BIOL 260 STAGE 03 EXAM
Effector actions
"Security teams" of innate immunity that eliminate the invader
Clonal selection is a critical theme in the adaptive immune response. The two main features are that...
- A population of lymphocytes able to recognize a functionally limitless variety of antigens is generated - Each lymphocyte recognizes and responds to only a single epitope
IgG...
- Accounts for 80-85% of circulating antibody levels - Easily leaves bloodstream and enters tissues
What long-lived protective outcomes have been produced in an individual who has overcome an infectious disease with an immune response?
- Accumulation of protective antibodies - Production of memory B + T cells - NOT accumulation of effector lymphocytes in previously infected area (effector lymphocytes will largely undergo apoptosis after infection is cleared)
Basic functions of helper T cells
- Activation of B cells - Activation of macrophages - Coordination of activities of B-cells, macrophages, and other T cells
The cytokines delivered when a helper T cell comes into contact with a B cell presenting an antigen it recognizes leads to...
- Activation of the B cell - Proliferation of the B cell - Formation of memory B cells - Class switching in the B cell
How immune cells communicate with each other
- Adhesion molecules - Surface receptors - Cytokines (chemical signals)
Metagenomics...
- Allows study of all microbiota from a given environment, even ones not cultured yet - Is the analysis of DNA extracted from a given environment - Is used by programs such as The Human Microbiome Project
Normal microbiota is...
- Also called microbiome - Includes resident and transient microbiota - Group of microorganisms routinely found growing on body of healthy individuals
Fever is...
- An important host defense mechanism - Strong indication of infectious disease
Host defenses against viruses
- Antibodies - Interferon - Apoptosis
When a pathogen hides within a host cell, it avoids...
- Antibody binding - Complement proteins - Engulfment by phagocytes Does NOT avoid: - Destruction by cytotoxic T cells + NK cells (these cells would still be free to detect and destroy a host cell that is harboring an intracellular pathogen)
Secretory IgA is found in the secretions that coat mucus membranes, thereby preventing pathogens from colonizing mucosal surfaces. What are methods that bacteria have evolved to evade or inactivate these antibodies?
- Antigenic variation, or altering bacterial structures to which the antibodies bind - Rapid turnover of pili structures to shed any bound antibody - IgA proteases that cleaves the antibodies, so they cannot bind to the pathogen
What steps and outcomes are shared by macrophages and B cells seeking help from helper T cells?
- Antigens are brought into the cell by endocytosis - Peptide fragments are loaded into MHC class II molecules for antigen presentation to helper T cells - Endocytosed antigens are broken down into peptide fragments - Helper T cells with the correct TCR bind to the peptide/MHC class II complex and deliver cytokines NOT shared steps and outcomes: - The cytokines delivered by the helper T cell activate the cell to proliferate and differentiate - The cytokines delivered by the helper T cell activate the cell to increase its killing capacity
Leukocytes
- Are WBC - Are important in host defenses
Costimulatory molecules...
- Are not initially produced on dendritic cells - Are produced in increasing amounts on dendritic cells after they have collected microbial peptides and are migrating to lymph nodes - Serve as "emergency lights" to let a T cell know the antigen being presented is from a microbe
TCRs...
- Are similar in structure to one arm of a Y-shaped antibody's Fab region - Are composed of 2 (NOT 4) polypeptide chains
People who have mutations in the genes encoding some PRRs are more likely to develop certain...
- Autoimmune disease - Inflammatory disorders
Early in viral replication, interferons play important role in limiting viral spread by causing cells to produce enzymes that, when activated, prevent viral replication. To void this, some viruses...
- Avoid interferon's effects by interfering with activation of enzymes - Encode proteins that shut down expression of host genes
Cell types that produce MHC class II molecules for exogenous antigen presentation include...
- B cells - Dendritic cells - Macrophages
LPS induces a response from which of the following cells of the immune system?
- B cells - Monocytes - Macrophages
An antigen is a molecule capable of interacting with...
- BCR - Antibody molecule
Inflammatory response...
- Can damage host tissues - Can help eliminate an invading microbe
Primary adaptive immune response...
- Can take a week or longer to become fully protective - Produces "memory" to be used later on in subsequent exposures - Will NOT be identical in nature to secondary response to same antigen at later date
Antibiotics disrupt normal microbiota and can predispose a person to infections caused by...
- Candida albicans growing in the vagina - Clostridium difficile growing in the intestine
Chemoattractants for phagocytic cells
- Chemokines - C5a - Products of foreign microorganisms - Phospholipids released by injured host cells - NOT C3b
Memory cells can speed up a secondary response b/c...
- Class switching has already occurred, so the response is already fine-tined in question - Affinity maturation has already taken place, increasing the ability to bind antigen - There are many of them
Mechanisms used by non-invasive pathogens to cause disease in the host
- Colonization of host mucous membranes followed by toxin production - Production of toxins that are then ingested
BCR
- Composed of 4 polypeptide chains - Has 2 peptide binding sites - Light chains have a single variable & single constant region domain, while heavy chains have a single variable and multiple constant region domains
4 basic functions of inflammation include all of the following...
- Containment at the site of damage - Localization of immune response - Elimination of the invader - Restoration of tissue function and capability at damaged site
Normal microbiota competitively excludes pathogens by...
- Covering binding sites that might otherwise be used for attachment by pathogens - Consuming available nutrients that could otherwise support growth of pathogens
Catalase
- Creates H2O and O2 as breakdown products - Breaks down hydrogen peroxide
The cells that have the general role of interacting with target cells and then inducing changes in them are...
- Cytotoxic T cells - Helper T cells
Functional categories of exotoxins based on tissues they affect
- Cytotoxins - Neurotoxins - Enterotoxins
Exotoxin is a...
- Damaging, harmful molecule produced by pathogens - Toxin that might leak into tissue fluid after a bacterial cell that produces it is lysed
TLRs on present on or in which of the following sentinel cells?
- Dendritic cells - Macrophages
Early on in an initial infection, __________ might be found in lymph draining into a lymph node
- Dendritic cells with processed antigens - Free antigens - WBC - NOT antibodies against the antigens present (in an initial response, the B cells would not have had time yet to make any antibodies against antigens present) - NOT endothelial cells
Basic functions of effector cytotoxic T cells include...
- Destruction of cancerous self cells - Induction of apoptosis in infected self cells - NOT assistance in activation of B cells or macrophages
Which of the following T cell events occur after activation?
- Differentiation of the activated cells into effector cell form - Formation of memory cells - Migration of effector cells out of secondary lymphoid organ and to site of infection - Proliferation of newly activated cells
Helper T cells orchestrate the immune response by...
- Directing the activities of B cells, macrophages, and T cells - Activating B cells and macrophages
Components of innate immunity
- Effector actions - Sensor systems - First-line defenses
During an immune response against "antigen X", which cell type(s) specific for "antigen X" would increase in number?
- Effector lymphocytes - Activated lymphocytes - NOT naive lymphocytes
Signs
- Elevated WBC count - Pus formation - Fever of 103 F - Rash
Many viruses cause flu-like symptoms as a result of the body's response to the infection. These symptoms include...
- Fever - Malaise - Body aches
Compounds recognized by TLRs anchored in the cytoplasmic membrane and facing the outside of the cell normally include which of the following?
- Flagellin - LPS - Lipoproteins
Examples of MAMPs
- Flagellin subunits - LPS - Peptidoglycan
Why are vaccines so important for protecting people against endotoxin-induced diseases such as tetanus and diphtheria?
- Following initial exposure to exotoxin, antibody production takes time during which exotoxin may cause extensive damage or even death - They induce production of specific antibodies that will immediately bind toxin if encountered later, providing fast protection **Not necessarily a problem with growth rate of microbe**
Secretory IgA is important in mucosal immunity and can be found in mucosal membranes of the...
- Genitourinary tract - GI tract - Respiratory tract
Which exhibit rapid mutation of antigens due to dependence on error-prone RNA polymerase or reverse transcriptase for replication?
- HIV - Influenza virus
TCR
- Has only one peptide binding site - Each chain in the receptor has a single variable and single constant region domain - Composed of 2 polypeptide chains
Two main categories of T lymphocytes necessary to mount a response against foreign pathogens
- Helper T cells - Cytotoxic T cells
Tolerance is crucial b/c it allows the immune system to...
- Ignore harmless substances such as pollen and proteins in food - Ignore body's own self molecules
During which of the phases or stages of an illness can a person be contagious to others?
- Illness - Incubation - Convalescence
Lysozyme, an enzyme that degrade peptidoglycan in bacteria, can be found...
- In saliva - In tears (lubricate and cleanse surface of the eye) - In the mucus of the small intestine (help protect the tissues around small intestine from microbes) - In phagocytic cells (help break down peptidoglycan of ingested microbes)
PRRs are located in 3 distinct locations...
- In the cytoplasm - In endosomes or phagosomes - On the cell surface
Which are mechanisms that either prevent complement protein activation or protect host cells from activated complement proteins?
- Inactivated C3b is not an effective opsonin - Proteins on host cells bind and inactivate C3b
Basic functions of effector cytotoxic cells (Tc cells)
- Induction of apoptosis in infected self cells - Destruction of cancerous self cells - NOT direct attack of extracellular bacteria
2 ways in which exotoxin can enter the body or its tissues
- Ingestion of preformed exotoxin molecules in food or water - Secretion of exotoxin by pathogens following infection of host tissues
Primary response
- Initially lacks affinity maturation; formed near end of the response - Slow to develop, taking 10-14 days - Initially lacks class switching; formed near end of response - Usually IgM in nature
Characteristics of the innate immunity response
- Initiation of identical responses upon repeated infections with the same microbe - Recognition of molecules that are common among microbes - Use of a combination of basic barrier systems and general purpose antimicrobial chemical secretions - NOT the capability to shorten response time and increase strength of response upon repeated exposures with the same antigen
In order for a naive T cell to become activated in a lymph node by a dendritic cell, it must...
- Interact with the costimulatory molecules on the dendritic cell to get a "second signal" for activation - Have antigen presented to it on an MHC molecule by the dendritic cell
Possible outcomes of a ligand binding to its receptor on a cell's surface
- Internal portion of the receptor becomes modified - A response is triggered in the cell, initiating some change - Numbers and types of the receptor on the surface may be altered to fit needs of the cell
Affinity maturation...
- Is a form of natural selection among proliferating B cells - Is a random process of spontaneous mutation - Occurs in B cells, allowing them to increase the binding-ability for their specific antigen over time
A carrier is an individual who...
- Is still contagious to individuals around him or her - Exhibits none of the symptoms of an illness - Harbors an infectious agent for a long time after infection
Why would it be disadvantageous to the pathogen to completely overwhelm the host defenses and kill its host?
- It may not be transmitted to another host - It would lose its nutrient source
Traits of a pyrogen
- Its production can be induced by detection of microbial products - It is often released by macrophages during an inflammatory process - It can elevate body temp. by acting on brain's body thermostat - It does NOT result from a macrophage undergoing apoptosis
Bacterial cell wall components to which host defenses are primed to respond
- LPS - Peptidoglycan
Chronic infections...
- Last a very long time - Can result in long-term contagiousness - Are usually subclinical - Are very slow to develop
In humans and other animals, killing "self" cells may...
- Limit spread of an infection - Eliminate cells no longer needed - NOT remove susceptible cells a pathogen might otherwise infect
Cytokines released by helper T cells (TH cells) help to coordinate, activate, and support...
- Macrophages - B cells - Cytotoxic T cells
TLRs are present on or in which sentinel cells
- Macrophages - Dendritic cells
Cell types capable of quickly binding up newly produced IgE...
- Mast cells - Basophils
Most exotoxins fall into 3 general categories that reflect their structure and general mechanism of action
- Membrane-damaging toxins - Superantigens - A-B toxins
T-indpendent antigens
- Might be repeating polymers of carbohydrates - Might be lipid variants such as LPS - Can activate B cells w/o T cell assistance - Possess long stretches of repeating subunits
Pus is composed of
- Neutrophils - Tissue debris
Characteristics of acute inflammation and its resolution
- New capillaries are formed - Macrophages clean up the damage and debris in area - Scar tissue forms - Neutrophils stop entering the site - Granulomas are NOT formed
TLRs in endosomes and phagosomes detect...
- Nucleotide sequences that are relatively common in bacterial DNA - Long molecules of dsRNA
Variables that affect the duration of the incubation period
- Number of infectious particles encountered - Host's general physical condition - Growth rate of pathogen
PRRs are generally found...
- On surface of innate immunity cells - Within the endosomes/phagosomes of innate immunity cells
Positive selection mechanisms in lymphocytes occurs...
- Only in T cells - Due to binding of TCR to MHC molecules during development and screening in the thymus
Protective outcomes of activation of the complement system
- Opsonization - Inflammatory response - Cell lysis - NOT phagocytosis (cannot b/c it is just a series of proteins) - NOT antibody production (B lymphocytes produce antibody molecules)
Symptoms
- Pain - Muscle soreness or weakness - Nausea
Dendritic cells gather material by...
- Phagocytosis - Pinocytosis - Tentacle-like extensions between epithelial cells to mucosal surfaces
Pyroptosis
- Process in which PRRs in a macrophage's cytoplasm are triggered, initiating self-destruction of that cell that triggers an inflammatory response - Programmed self-destruction that triggers inflammatory response
A secretory component is added to IgA before it is deposited in the mucus over a mucosal surface in order to...
- Protect it from destruction by enzymes in the layer of mucus - Help attach it to layer of mucus NOT true: - Increase its ability to bind to antigen (secretory component has nothing to do with antibody's ability to bind antigen)
Benefits of the normal microbiota to our health
- Protect us against infection - Produce beneficial compounds - Help us digest our food
In addition to phagocytosis, neutrophils kill microbes by...
- Releasing antimicrobial peptides - Releasing destructive enzymes - NOT producing PRRs (PRRs allow cells to detect microbes, but they do not have a direct antimicrobial effect)
Areas that have a mucous membrane lining
- Respiratory tract - Genitourinary tract - Digestive tract
Secretory IgA (sIgA), the dimer form of IgA, can be found in...
- Saliva - Tears - Breast milk
What events occur as a result of memory B cells being activated as part of the secondary response?
- Second round of affinity maturation - Proliferation - Quick differentiation into plasma cells - NOT class switching
Damage-inducing mechanisms of eukaryotic parasites include...
- Secretion of enzymes that damage host tissues or cells - Successful competition for nutrients in the intestinal tract, leading to malnutrition - Growing large enough to block organ openings - Induction of strong inflammatory response that is damaging to the host NOT mechanisms: - Spreading through bloodstream to every organ system of body (most parasites have a favored tissue type that will attach to or attack) - Impairment of immune responses by attacking and degrading bone marrow (most parasites cannot gain easy access to inner areas of the bones)
Factors that can lead to excessive growth of the yeast Candida albicans include...
- Severe burns - Uncontrolled diabetes - Inhibition of normal microbiota by antibiotic treatment - AIDS
The increase in temp. from a moderate fever helps the body fight an infection by...
- Slowing or preventing the growth of microbes that have lower optimum temp. - Enhancing inflammatory response - Enhancing phagocytic activity and the multiplication of lymphocytes - NOT reducing rate of respiration - NOT decreasing rates of human enzymatic reactions
Examples of secondary lymphoid organs
- Spleen - Tonsil - Lymph nodes
C3 convertase
- Splits CP3 - Forms at the convergence of the 3 pathways of complement activation - Is NOT the final product of the complement activation cascade
If scarring from the inflammatory response damages the inner areas of the fallopian tubes in the female reproductive tract, there is higher likelihood of...
- Sterility due to prevention of fertilization by physical blockage of tubes - Ectopic pregnancy (fertilized egg implants outside uterus)
A virus might avoid extracellular antibody binding by...
- Stimulating syncytium formation (forced fusion of cells) - Moving directly from one cell to another - NOT destroying the target cell, releasing the virus (would expose virus particles to antibodies)
Secondary response
- Strong levels of affinity maturation already in place - Class switching has already taken place - Usually NOT IgM in nature - Faster to develop due to preformed memory cells
Immune cells communicate with each other through...
- Surface receptors - Cytokines - Adhesion molecules
4 signs of inflammation that are always present
- Swelling - Redness - Pain - Heat
If an immune system lost the ability to make helper T cells, the B cells could still be activated by...
- T-independent antigens - Polysaccharides
In the human intestinal tract...
- The body absorbs short-chain fatty acids - Microbes ferment breakdown products, making short-chain fatty acids - Microorganisms break down most types of dietary fiber
Why is the MAC formation more damaging to Gram-negative cells than to Gram-positive cells?
- The outer and cytoplasmic membranes serve as targets of MAC - The thick layer of peptidoglycan of Gram-positive bacteria prevents MACs from reaching cytoplasmic membrane **Cell wall is not target of the MAC**
True statements about granulomas...
- They are formed as part of the disease process in TB - They wall off and contain pathogens, preventing their spread - They can damage the host by interfering with normal tissue function NOT true: - They never harm the host, they are always protective (granulomas can harm a host by interfering with normal tissue functions)
Possible fates of activated B cells in a primary response
- They can differentiate into plasma cells - They can become memory B cells - They can proliferate - They can NOT assist in the activation of other B cells
Which descriptions are true for macrophages but not neutrophils?
- They have a longer life span in the tissues - They are always present in the tissues, whether slow wanderers or stationary NOT TRUE: - They release granule contents and DNA strands to entrap and destroy microbes - They have more killing power
Humoral immunity is generally used to eliminate extracellular antigens such as...
- Toxins - Viruses in tissue fluids - Bacteria - NOT TB pathogens ingested by macrophages
The leftover bits of material that either cannot be broken down by a phagocytic cell or are purposely left partially intact are...
- Used to display bits of invaders to cells of the adaptive immune system - Exocytosed by fusing internal vesicle with external plasma membrane
3 gene segments used to encode an antibody heavy chain variable region...
- Variable segments - Diversity segments - Joining segments
A baby may acquire normal microbiota in which ways?
- Via contact with other humans - Due to exposure to microbes in the environment - From food consumed after birth - During birth from mother's birth canal
What are differences in viral RNA that make it a target for binding by RIG-like receptors, while cellular RNA is left alone?
- Viral RNA will often form double-stranded areas, whereas eukaryotic RNA does not - Viral RNA is not capped at the 5' end - it has 5' phosphate groups exposed instead
A granuloma...
- Walls off material that cannot be destroyed - Contains T cells - Contains macrophages - Is an example of cooperation between innate and adaptive immune responses - Does NOT function as a last-ditch destruction mechanism to destroy infectious agents
Examples of tissue damage or irritation facilitating spread of pathogens to new hosts
- Watery diarrhea induced by cholera - Extreme coughing fits induced by whooping cough infection - NOT skin rash caused by allergic reaction
As the dendritic cells that have engulfed antigen migrate into lymph nodes, they...
- Work on processing the antigen to load its peptides into MHC molecules - Begin to produce costimulatory molecules that will help activate naive T cells
Traits of chronic inflammation
-Granulomas form -Giant cells accumulate in the area -The infection may not be completely eliminated, but largely controlled - NOT a large influx of neutrophils occurs in infected area
Why might it be a good thing for a host to kill an infected self cell?
If it is harboring an infectious agent, killing the cell may prevent adjacent cells from also becoming infected by that infectious agent
N. gonorrhoeae evades the most common antibodies found in mucosal secretions by producing ___ protease
IgA
Which protective maternal antibody is present in colostrum?
IgG
B cells in the lymph nodes, producing antibodies for the blood and tissues, would most commonly switch to ___ production. But B cells in the MALT would most commonly switch to ___ production, providing mucosal immunity
IgG; IgA
Dysbiosis
Imbalance in microbiome
When ___ complexes form after a throat infection with S. pyogenes, they can deposit in the glomeruli of the kidneys, causing a destructive inflammatory process known as acute glomerulonephritis
Immune
Indirect damage
Immune response
Lymphocytes
Include B cells and T cells; primary cell type involved in adaptive immune responses
Cytokines released by Tc cells encountering a target call strengthen immune response by causing nearby cells to...
Increase antigen processing and presentation
Young children are particularly susceptible to many encapsulated bacteria b/c polysaccharides are T-___ antigens to which this age group responds poorly
Independent
Carrier
Individual who still harbors an infectious agent for months or years after initial infection w/o signs or symptoms
If you hear that a bacterium uses a type III secretion system to inject effector proteins into host cells, you can conclude that the proteins...
Induce a change in the host cells
Main "weapon" that a Tc cell uses
Induction of apoptosis
In response to tissue damage or introduction of microbes into normally sterile body sites, _____ occurs. The purpose of this is to contain the site of damage, localize the response, eliminate the invader, and restore tissue function
Inflammation
Collective term for various pro-inflammatory cytokines and chemicals
Inflammatory mediators
NK cells belong to group of lymphocytes called...
Innate lymphoid cells
Why have pathogens evolved mechanisms to evade immune responses?
Inside the body, they will be under attack by these responses. Evasion will allow them to survive.
T cells
Interact with target cells and then cause changes in those cells
If a virally-infected cell's PRR detect viral nucleic acid, then that cell will produce __________
Interferon
Symbiosis
Intimate relationships between the microorganisms and the human body; means "living together"
___ pathogens are able to penetrate the body's first line defenses and then multiply in host tissue
Invasive
Mannose-binding lectins (MBLs)
Involved in activation of complement system via lectin pathway
Eosinophils
Involved in immune response to parasitic worm infections, allergy, and inflammatory reactions
Different varieties of antibody specificities are created by...
Joining together any combo that includes one V, one D, and one J segment
Tumor necrosis factor
Kills tumor cells, initiates the inflammatory process, triggers apoptosis
Example of endotoxin
LPS
Immature lymphocytes
Lack fully developed antigen-specific receptors
Incubation period
Length of time between initial infection and development of symptoms
Mucosa-associated lymphoid tissue (MALT) and skin-associated lymphoid tissue (SALT) are both examples of...
Less-organized (diffuse) secondary lymphoid organs
A molecule that can bind to a given surface receptor is a ____ for that receptor
Ligand
Memory lymphocytes
Long-lived descendants of activated lymphocytes that can quickly respond when a specific antigen is encountered again
An M cell is a specialized cell of the MALT that samples the materials from the intestinal ___. As such, it can be exploited by pathogens to cross membranes.
Lumen
Lymphatic vessels carry ___ to the lymph nodes
Lymph (the extracellular fluid that might carry antigens into the lymph nodes)
______ are responsible for adaptive immune responses and include two major groups: B cells and T cells
Lymphocytes
Certain TLRs within endosomes or phagosomes do not become fully functional until the vesicle fuses with ____, exposing the contents of the vesicle to low pH and digestive enzymes. B/c of this, TLRs are less likely to contact host nucleic acid
Lysosomes
Shigella species are ingested by macrophages after being taken across epithelial membrane via _ cells. However, they are not destroyed by these macrophages; instead, the bacteria induce ___ in macrophages in order to effect their release
M; apoptosis
Positive selection in T cells permits only those cells that recognize ___ molecules to develop further
MHC
Cytotoxic T cell recognizes...
MHC class I molecules
Helper T cell recognizes...
MHC class II molecules
Production of a fake ___ class I molecule on the surface of a cell infected with cytomegalovirus lets the infected cell evade ___ by NK cells
MHC; apoptosis
Mucous and antimicrobial secretions
Material that bathes and protects the exterior barriers
IgG
Maternal immunoglobulin that protects fetus and newborn
A B cell in a lymph node is a ___ type of lymphocyte, while a plasma cell is a fully ___ lymphocyte
Mature but naive; differentiated
Memory is an important trait of the adaptive immune processes. Which disease will generally only occur in an individual once, priming a protective adaptive immune response that will provide the person with lifelong immunity?
Measles, mumps, and diphtheria
To avoid destruction by the complement system, some microbes avoid formation of...
Membrane attack complex (MAC)
BCR
Membrane-bound version of the specific antibody that the particular B cell is programmed to produce
Both B and T cells can form ___ cells that react quickly if the same antigen is encountered at a later time
Memory
Human pathogen
Microbe capable of inducing damage to human body
Infection
Microbe establishing itself on or in the body of a parasitic relationship
Dimorphic fungi occur as ___ in the environment and another form, usually yeast, in the body
Mold
MAMPs
Molecular patterns commonly found on microbes
PRRs
Molecules that allow the body's cells to "see" signs of microbial invasion
Macrophages have a lifespan of weeks to months. To replace them, ___ leave the bloodstream and differentiate into new macrophages
Monocytes
An activated macrophage has ___ killing power than its unactivated counterpart
More
IgG
Most abundant class in blood and tissue fluids
IgA
Most abundant class produced, but most is secreted into mucus, tears, and saliva
Cells of the immune system...
Move from one part of the body to another via the body's circulatory systems
The mucociliary escalator's function in respiratory tract is to...
Move microbes and other material trapped in the mucus up and out of the tract, where it can be eliminated safely
Most invasive pathogens enter the tissues via...
Mucous membranes
Colony-stimulating factors (CSFs)
Multiplication and differentiation of leukocytes
When a BCR binds antigen, and the naive B cell is activated by confirmation from a helper T cell, the B cell then begins to...
Multiply
An antigen interacting with a T cell receptor...
Must be broken down into peptide fragments and presented on an MHC molecule
Antibody-dependent cellular cytotoxicity (ADCC) takes place when...
NK cells bind the Fc region of antibodies coating an infected self-cell or tumor cell, and then induces that cell to undergo apoptosis
Endotoxin is the LPS layer of Gram-____ bacteria
Negative
Gram-____ cells are more susceptible to lysis by MAC formation due to outer membrane and thin peptidoglycan layer of their cell wall structure
Negative
Neutrophils can release their cell contents to form NETs, which stands for...
Neutrophil extracellular traps
Class switching is beneficial in immune responses b/c...
Not all types of antibodies are equally effective in clearing all the different antigen types
Infectious dose
Number of microbes necessary to establish infection
Molecular mimicry
Occurs when a pathogen tries to disguise itself by coating its surface with molecules that are similar to those found in the host so that it can avoid host immune responses
Example of adhesion molecules in action
Occurs when phagocytic cells are needed in tissues; the endothelial cells lining the blood vessels make adhesion molecules to "grab" cells from the blood
Aflatoxin
One of the most potent mycotoxins produced by Aspergillus flavus, which grows on grains and nuts; can damage liver
In a situation where a normal protein from host A elicits an immune response when it is transplanted into host B, it is immunogenic...
Only for host B, b/c it would be considered a self-antigen in host A and therefore would not elicit a response in that host
When antigen is introduced...
Only the B cells capable of making the appropriate antibody can multiply
Compounds recognized by TLRs anchored in the cytoplasmic membrane are generally components of the...
Outermost layers of microbial cells
With respect to the body's borders, the contents of the digestive tract are...
Outside the body
Pathogens can be distinguished from other microbes by their ability to...
Overcome body's immune defenses and cause damage
Septic shock
Overwhelming systemic immune response, characterized by a dramatic drop in BP, disseminated intravascular coagulation (DIC), and fever
C-type lectin receptors
PRR that detects certain carbohydrate molecules found on surface of cells
DAMPs
Patterns that might be released from our own cells when they become damaged but would otherwise be hidden away
By surviving within WBC called ___, some pathogens are able to hide from antibodies, control some aspects of immune response, and be transported to other locations in the body
Phagocytes **Not neutrophils - they are short-lived and therefore would not transport pathogen to other parts of body**
Microbes that have been opsonized are easier to engulf b/c...
Phagocytes have receptors for opsonin proteins such as C3b on their surface
Main role of neutrophils
Phagocytosis
If antibodies bind to ___, structures on bacterial cells used for adherence, the bacteria are not able to attach to host tissues and can be more easily washed away or targeted for destruction by immune responses
Pili
IgG is the only antibody that is transported across the _________ into the fetus's bloodstream
Placenta
A ___ cell typically undergoes apoptosis after several days, but ___ continue multiplying and differentiating for a longer period of time, allowing for increases in overall antibody levels
Plasma; activated B cells
When memory B cells become reactivated in a secondary response, some rapidly form _____ cells to produce antibodies. Others begin undergoing _____ to produce an additional base of cells to work with.
Plasma; proliferating
Analogy for macrophages' role
Police officers who routinely protect city streets
Good example of a T-independent antigen
Polysaccharide b/c of its identical, evenly spaced repeating epitopes
Normal microbiota
Population of microbes that routinely grow on the body surfaces
Membrane-damaging toxins often form ___ in the membranes of phagocytes and other cells
Pores
Constant region
Portion of an antibody molecule that has a consistent A.A. sequence regardless of epitope recognized
Damaging consequence of inflammation
Possibility for enzymes and toxic products from phagocytic cells to damage self tissues
Bacteremia
Presence of bacteria in the bloodstream
Viremia
Presence of free viral particles in the blood
Toxemia
Presence of toxins in the bloodstream
Purpose of major histocompatibility complex (MHC) class I and class II molecules
Present digested antigen fragments
When a B cell processes and presents the antigen it recognized to a TH cell, it...
Presents a variety of peptides from the antigen
If a person lost the ability to make memory B cells, then the secondary response would be nearly identical to the...
Primary humoral response
Primary vs. secondary infections
Primary influenza infection weakens respiratory tract defenses, making secondary pneumonia more likely and more deadly
If a macrophage's PRRs detect bacterial products, then that macrophage will produce...
Pro-inflammatory cytokines
Some pro-inflammatory cytokines cause endothelial cells of local blood vessels to...
Produce adhesion molecules that loosely "grab" phagocytes
E. coli in the GI tract
Produce colicins, a group of proteins that are toxic to certain bacteria
Lactobacillus species in the vagina
Produce lactic acid as a fermentation end product; the resulting low pH inhibits growth of some pathogens
While the innate immune system responds to general molecular patterns associated with a variety of microbes, the adaptive response...
Produces multiple, highly specific individual responses to small subcomponents of individual microbes
Listeria monocytogenes can escape from a phagosome inside a phagocytic cell before it is destroyed by...
Producing a molecule that forms pores in the phagosome membrane, allowing the bacteria to escape
Most important mechanism for destruction of the contents of a phagolysosome
Production of a respiratory burst in which O2 consumption increases dramatically, allowing an enzyme to produce ROS
The main function of helper T cells is...
Production of cytokines that direct and support other immune system cells
Apoptosis
Programmed cell death that does not trigger an inflammatory response
Mechanisms of ___ pathogenesis are better understood
Prokaryotic
Lactoferrin and transferrin
Proteins that bind iron, keeping it at low levels and away from microbes that need it
Due to its dense layering of tightly joined cells, the skin...
Provides a highly efficient barrier that prevents microbes from entering our deeper tissues
Helper T cell
Provides the second signal confirming that an antigen-activated B cell needs to start proliferation and differentiation into a plasma cell
Imprecise joining can lead to an increase in antibody diversity due to changes in the ___ frame of the encoded protein
Reading
After a virus binds to a specific host cell ___, it enters the cell via either receptor-mediated ___ or by fusion of the viral envelope with the plasma membrane of the target cell.
Receptor; endocytosis
TH2
Recruit eosinophils and basophils; helminth invader
If macrophages cannot rapidly clear invading microbes, these phagocytic cells produce cytokines that...
Recruit neutrophils
TH17
Recruit neutrophils; extracellular bacterium invader
A human is infected with a bacterial pathogen whose optimum growth temp. is 33 C. If the infection leads to a moderate fever, this will...
Reduce the growth rate of the pathogen
Fab region
Region at the end of each arm of the Y-shaped antibody molecule responsible for antigen binding
When a phagocyte encounters something too large to engulf, it will...
Release its toxic contents into the surrounding area in an attempt to degrade the particle
Primary end outcome of activation of the complement system is...
Removal and destruction of invading microbes
When a bacterium is defined as being serum resistant, it means it is...
Resistant to complement proteins in the serum that might otherwise kill the cells
When a helper T recognizes a peptide presented by a B cell or macrophage, it will...
Secrete cytokines that will assist in activation of B cell or macrophage
Salmonella species prevent fusion of lysosomes with the phagosome by...
Secreting a protein that blocks fusion processes
Complement system
Series of proteins circulating in blood and fluid that bathes the tissues that work to enhance the adaptive immune processes
In the classical pathway of complement system activation, the cascade of reactions is activated when a specific complement system protein attaches to...
Side-by-side Fc regions of antibodies bound to an antigen
Epitope
Small region of an antigen molecule that is the site of antibody binding
When complement system protein C3 is activated, it...
Splits into C3a and C3b
NLRs are cytoplasmic proteins that detect microbial components. Why would a cell need detectors in the inside, rather than outside?
Such detectors could alert the cell when its borders have been breached
If regulatory T cells were absent or impaired, a person might be more likely to...
Suffer from autoimmune diseases from failing to shut down anti-"self" responses
Unlike the enterotoxins of V. cholerae and pathogenic E. coli strains, the exotoxins produced by S. aureus strains that cause foodborne intoxication are ___
Superantigens
When Mycobacterium tuberculosis cells direct their uptake by macrophages in the alveoli of the lungs, they...
Survive within macrophages that have not been activated
Subclinical infection
Symptoms of disease or absent or too mild to be noticed
T-dependent antigens
T-helper cells are required for confirmation
A conjugate vaccine is composed of a polysaccharide attached to a protein, which converts a...
T-independent antigen to a T-dependent antigen
Processing and presentation of antigens is necessary for interaction with which type of lymphocyte antigen receptor?
TCRs
Indirect binding of a phagocyte to a bacterial cell occurs when...
The cell's receptors first bind to opsonins that have coated the bacterial cell
Peristalsis in the intestines is...
The contraction of smooth muscle elements in the intestine to propel food, liquid, and microbes along (and ultimately out) of it; this propulsion is important for digestion but also serves to eliminate microbes from the vicinity
As with bacterial pathogenesis, damage due to viral infection is often due to...
The host responses
The human intestinal microbiome allows the body to extract more energy from foods. One reason for this is that...
The human genome encodes relatively few enzymes that degrade complex carbohydrates
The key step to a phagosome becoming a phagolysosome occurs when..
The phagosome fuses with enzyme-filled lysosomes
When oral antibiotics inhibit the Lactobacillus species that normally predominates in the vagina of mature females, which of the following can occur?
The yeast Candida albicans is allowed to multiply unchecked, resulting in fungal infection of the area
What function do cell surface receptors perform that is similar to our eyes and ears?
They allow a cell to receive signals from external environment
T cell maturation site
Thymus
Main function of lymphatic system
To allow antigens to interact and activate lymphocytes
Example of superantigen
Toxin shock syndrome toxin (TSST)
Direct damage
Toxins
Virulence factors
Traits of a microbe that specifically allow it to cause disease
If a macrophage detects microbial contents in its cytoplasm, it...
Triggers an inflammatory response
T/F: A NK cell is a type of lymphocyte
True
T/F: Antigen variation in N. gonorrheae occurs when the bacteria change the structure of their pili, rendering highly specific host antibodies previously produced unable to bind to new and different structures
True
T/F: Defensins create pores in bacterial cytoplasmic membranes, leading to leakage of ions and fluids and resulting in bacterial death
True
T/F: Due to wide differences in life cycles and tissues affected by eukaryotic parasites, the extent and type of damage induced varies tremendously
True
T/F: Endotoxin can cause septic shock
True
T/F: Hygiene hypothesis states that insufficient exposure to microbes can lead to development of allergies
True
T/F: Some viruses control the host cell protein p53 to regulate or prevent apoptosis in infected cells
True
Dendritic cells
Type of antigen-presenting cell; responsible for initial activation of naive T lymphocytes in lymph nodes during a cell-mediated immune response
Giardia lamblia
Uses a disc that functions as suction cup to attach to intestinal surface
Bacterial pathogens that invade the body through the skin...
Usually require a skin-damaging injury in order to gain entry through the tough barrier
When comparing two different antibody molecules that bind to different epitopes, the A.A. sequence in the ___ region of each molecule will be different
Variable
The A.A. sequence of the end of the "arms" of different antibody molecules is...
Variable, thus providing the basis for antibody specificity to antigens
A prime example of the protective actions of cytotoxic T cells can be found in attacks against...
Virally infected self cells, inducing apoptosis
Neutralization prevents...
Viruses and toxins from attaching to target cells and damaging them
Cell-mediated immunity (CMI) deals with intracellular pathogens and antigens such as...
Viruses replicating in a cell
Granulomas are an important defense mechanism b/c they...
Wall of the offending agent, preventing the infectious microbes from escaping to other cells
Interferon response
Warns nearby cells that a virus is present
Why are complement regulatory mechanisms needed?
Without them, there might be inappropriate activation of the system when there isn't an infectious agent present (help to turn off the cascades, not to activate them)
Superantigen
Works by binding the MHC class II molecule on an antigen presenting cell with many different possible TCRs on helper T cells, causing them to become inappropriately activated
The activator for inactive antiviral proteins (iAVPs) is the presence of viral ___ within the host cell
dsRNA
Communicable or contagious diseases
infectious diseases that spread from one host to another
Steps that result in directed uptake of Salmonella species in intestinal epithelial cells
1. Bacteria adhere to host cells 2. Bacteria use a type III secretion system to deliver proteins into host cells 3. Bacterial proteins cause rearrangement of actin molecules in host cell 4. Characteristic membrane ruffling occurs on host cell's surface 5. Host cell's membrane encloses around bacterial cells, bringing them in
Phagocytosis involves multiple steps, each of which is potentially a target for microbes to modify or avoid as a means of evading immune response mechanisms. What is the correct order for the steps involved in phagocytosis of a microbe?
1. Chemotaxis 2. Recognition and attachment 3. Engulfment 4. Fusion of phagosome with lysosomes
Order of the main events that would take place during an inflammatory response
1. Dilation of small blood vessels in the affected area 2. Leakage of fluid from blood vessels in the affected area 3. Migration of leukocytes out of the bloodstream and into the tissues of the affected area
Steps that occur during the clonal selection process
1. Lymphocytes gather in secondary lymphoid organs 2. Antigens bind to lymphocytes that have a specific antigen receptor for an epitope on the antigen 3. The lymphocytes being activated need the antigen as a first single, but also a second signal to confirm danger and allow activation 4. When activation is confirmed, proliferation occurs 5. Differentiation into effector cell form (plasma cell, helper T cell, cytotoxic T cell) occurs
Order in which cells would arrive, via chemotaxis, at an inflamed or infected area following recruitment as a result of release of inflammatory mediators at site of infection
1. Neutrophils 2. Monocytes (which mature into macrophages at site of infection)
Koch's Postulates
1. The microorganism must be present in every case of the disease 2. The organism must be grown in pure culture from diseased hosts 3. The same disease must be produced when a pure culture of the organism is introduced into susceptible hosts 4. The organism must be recovered from experimentally infected hosts
Koch's Molecular Postulates
1. The virulence factor gene or its product should be found in pathogenic strains of the organism 2. Mutating the virulence gene to disrupt its function should reduce virulence of pathogen 3. Reversion of mutated virulence gene or replacement with a wild-type version should restore virulence to the strain
There are _ identical light chains and _ identical heavy chains in an antibody molecule
2; 2
_ general types of constant regions that correspond to major classes of immunoglobulin (Ig, aka antibody) molecules
5
Positive and negative selection processes for T cells are so strict that _% of developing T cells undergo apoptosis in thymus
95
C3 convertase
A complement protein that is unstable and can spontaneously cleave into C3a and C3b, and by doing so plays an important role in activating alternative pathway
Plasma cell typically survives...
A few days
Effector protein
A protein that a bacterium injects into a host cell, with the result the host cell's cytoskeleton structure is altered
Homeostasis
A state in which the immune system must destroy pathogens while maintaining relatively stable conditions within the body
Macrophages
A type of cell specialized for phagocytosis that needs the assistance of helper T-cells to become fully activated, showing an example of the cooperation between innate and adaptive response systems
Macrophages
A type of cell specialized for phagocytosis; needs the assistance of helper T cells to become fully activated, showing example of cooperation between innate and adaptive response systems
During an initial or primary exposure to an antigen, adaptive immunity generally takes about ___ to build
A week
Activated lymphocytes
Able to multiply because they have encountered an antigen they recognize and have received signal confirming that the antigen requires a response
An effector cytotoxic cell should recognize presented antigen when cell is displaying peptide fragments of endogenous proteins that are...
Abnormal (cancerous) or non-self (replicating virus or microorganism) loaded into its MHC class I molecule
Regional infection
Acting on a variety of cells in the general vicinity of the cytokine's release
Local infection
Acting only on the very few cells in the immediate vicinity of the cytokine's release
Systemic infection
Acting throughout the organism, and not restricted to a particular area
TH1
Activate macrophages and stimulate Tc cells; intracellular virus invader
A naive T cell that recognizes antigen presented by a dendritic cell displaying co-stimulatory molecules can become...
Activated
C5a
Activated complement molecule that can serve as a strong chemoattractant for phagocytic cells
Complement activation
Activated components remove and destroy invading microbes; acts in combination with the adaptive defenses
C3a and C5a
Activated members of the complement system that can cause inflammatory changes in blood vessels
When a macrophage receives assistance from a helper T cell in the form of cytokines, it...
Activates more potent destructive mechanisms for the cell, enhancing its antigen clearing capacity
Highly specific response of ___ immunity will protect an individual from one disease, but not a different illness caused by a different microbe
Adaptive
Common non-pathogenic E. coli strains usually possess an ___ that only allows them to bind to large intestines. By contrast, pathogenic E. coli strains have additional ___, which broadens range of tissues to which they can attach.
Adhesin; adhesins
Memory B cells can scavenge for very low concentration of antigen in a secondary response b/c...
Affinity maturation has already made their receptors fine-tuned for binding the antigen
Memory B cell production occurs...
After class switching has taken place
Hypersensitivity reactions to normally harmless materials such as foods, dusts, and pollens are also known as ___ reactions
Allergic
An antigen is a molecule that is ___ able to interact with an antibody or lymphocyte, but sometimes without inducing a response; if the antigen is ___, then it elicits an immune response
Always; immunogenic
Physiological variations within the host
An example is hormonal shifts during pregnancy. These would be changes to the normal homeostatic patterns in the host organism that are not due to pathogenic infection.
Direct result of activities of the human host
An example of this consuming different amounts of food. these would be changes in the way a human interacts with the surrounding environment that may alter the normal microbiota composition.
T cells that recognize a peptide presented by a dendritic cell, yet do not receive co-stimulatory molecule signals, will be induced to become ___
Anergic
Bacterial pathogens that survive the innate defenses will soon encounter ___, a component of the adaptive defenses
Antibodies
The component of the adaptive defenses that protects against bacteria invading blood and other body fluids is...
Antibodies **Not Tc cells - these destroy infected host cells**
Antigen
Antibody generator
B cells
Antibody response
Clonal selection theory describes how the body can make a seemingly unlimited range of...
Antibody specificities
Plasma cell
Antibody-producing descendant of a B cell
People with vitamin D deficiency are more susceptible to certain diseases. This might be related to observation that the vitamin regulates the expression of some _______
Antimicrobial peptides (AMPs)
If a person is suffering from an exotoxin-induced disease like tetanus, treatment with ___, or a suspension of neutralizing antibodies, would be helpful
Antitoxin
Interferon
Antiviral and other roles
B cells with anti-self BCRs undergoing negative selection in the bone marrow are induced to undergo ___
Apoptosis
W/o continuous stimulation by presence of antigen, effector lymphocytes will undergo ___
Apoptosis
Interferon results in...
Apoptosis of infected cells
Functions of IgD in blood serum...
Are not well understood
T-dependent antigens typically...
Are protein molecules
Neutrophils...
Are usually the first cell type recruited to a damaged area
The PRRs of an innate immunity cell allow that cell to tailor its response according to the general category of pathogen by determining...
Assortment of the pathogen's MAMPs
Pathogens must first ____ to host cells in order to initiate an infection
Attach
A pathogen that is able to avoid fusion of lysosomes with phagosomes can...
Avoid destruction by phagocytes
Protozoa and helminths may live within host cells to...
Avoid exposure to antibodies and other defenses
Mechanism microbes may utilize to evade immune responses
Avoid formation of MAC after complement system activation
Positive selection take place in T cells but not in B cells b/c...
B cells do not need to have peptides presented to them on an MHC molecule, so it does not matter if they can bind MHC or not
Skin
Barrier that keeps microbes outside of the body
Mucous membranes
Barrier that lines many body cavities and organs; keeps microbes out of deeper tissues
Epithelial cells that line the exposed surfaces of the body are tightly packed together and rest on the ____ membrane
Basement
Anergy
Being unresponsive to an antigen
The function of the two arms of the Y-shaped antibody molecule is to...
Bind epitopes, or antigenic determinants
Capsules on microbes help them avoid recognition and attachment by phagocytes by...
Binding host complement regulatory proteins that inactivate C3b, preventing opsonization
One way that NK cells identify target cells for antibody-dependent cellular cytotoxicity (ADCC) is...
Binding to Fc regions of antibodies that have attached to the target
An effector cytotoxic T cell (Tc) makes contact with target by ... As a result of that contact, it induces the cell to undergo apoptosis
Binding to an antigenic peptide:MHC class I molecule complex
Plasmodium vivax
Binds to Duffy blood group antigen on RBC
IgE
Binds to mast cells and basophils
B cell maturation site
Bone marrow
Primary lymphoid organs
Bone marrow and thymus
Mast cell
Bound to connective tissue and contains granules containing mediators of inflammation and allergy such as histamine
Human body temp. is kept around 37 C by a temperature-regulation center in the ___
Brain
Analogy for function of secondary lymphoid organs
Busy coffee shop where many cellular meetings take place
How do viruses attach to target cells?
By binding to specific host cell receptors prior to either membrane fusion or receptor-medicated endocytosis
C3b is both a product and a trigger for the alternative complement cascade. How can this occur?
C3 is unstable and can spontaneously split into C3a and C3b at a low rate
Cryptococcus species produce a very large ___ that interferes with phagocytosis
Capsule
M proteins in cell wall of S. pyogenes work in a manner similar to ___, binding a complement regulatory protein that ___ C3b, thereby preventing it from being an effective opsonin
Capsules; inactivates
Chemokine
Chemotaxis of immune cells
Exposure to members of normal microbiota allows immune system to learn to distinguish harmless microbes from pathogens. Failure to do this can result in...
Chronic inflammatory conditions
All B cells are initially programmed to differentiate into plasma cells that secrete IgM antibodies. It is only through ___ switching that they can shift to producing one of the other types.
Class
Antibody-antigen binding can activate the complement cascade via the...
Classical pathway
When a toxin or virus is neutralized, it is...
Coated by antibody molecules
Opsonization
Coating a microbial surface with proteins or other molecules, making it easier for it to be engulfed by a phagocytic cell
Immune complex
Combination of an antibody and antigen bound together; required to begin the classical pathway of complement activation
Peptidoglycan
Common bacterial cell wall component that can induce septic shock if it reaches high enough levels
Example of acute infection
Common cold
During inflammation, ___ system proteins leak out into tissues to become cleaved and activated and attack microbes
Complement
The stem of the Y-shaped antibodies has a highly...
Conserved A.A. sequence that provides the "red flag" for other immune system components to eliminate the antigen
Inflammatory response
Coordinated response that allows various protective components to leak into tissues
Koch's Postulates
Criteria that Robert Koch used to link the organism Bacillus anthracis with the livestock disease anthrax
Which is easier for a phagocyte to engulf?
Cross-linked large immune complexes over individual antigens that are well separated
Why is production of cross-reactive antibodies different than formation of immune complexes in terms of damage associated with adaptive immunity?
Cross-reactive antibodies bind to self structures, while immune complexes do not
Different subsets of effector T cells produce different ___, thereby directing the immune system toward an appropriate response for a given antigen
Cytokines
If macrophages cannot rapidly clear invading microbes, those phagocytic cells produce ___ that recruit neutrophils
Cytokines
Tc cells encountering a target cell produce ___ that strengthen the immune response in nearby cells
Cytokines
When the helper T cell recognizes a peptide presented to it by a B cell or macrophage, it delivers signals known as ___ that activate the cell
Cytokines
PRRs in a cell's _________ allow the cell to monitor its own internal contents for signs of invasion
Cytoplasm
NLRs are ____ proteins, while TLRs are ____ proteins. Both detect PAMPs
Cytoplasmic; membrane-bound
CD8
Cytotoxic T cell
The inflammatory process is typically induced by PRRs detecting...
DAMPs and MAMPs
Immunocompromised
Defined as having weaknesses or defects in their innate or adaptive immune responses
Cutibacterium species in hair follicles
Degrade lipids, releasing fatty acids that inhibit pathogen growth
C5a peptidase
Degrades complement component C5a
Virulence
Degree of pathogenicity of an organism
Coxiella burnetii is a microbe that can survive phagocytosis by...
Delaying fusion of the phagosome and lysosome until it has equipped itself to survive within the phagolysosome
T cells are activated by ___ cells, which can be considered the scout of the immune system
Dendritic
Cross-presentation occurs when a...
Dendritic cell that has ingested an antigen presents it to T cells on both MHC class I and II molecules
Effector lymphocytes
Descendants of activated lymphocytes that are armed with protective abilities; expresses specific traits that help eliminate invaders
Membrane-damaging toxins are cytotoxins that...
Destroy plasma membranes of cells, causing the cells to lyse
Butyrate, which is produced as a result of bacterial fermentation of ___, is an important energy source for epithelial cells that line the large intestine
Dietary fibers
Interleukin
Diverse overlapping functions important in innate and adaptive immunity
Most fungi are saprophytes and therefore...
Do not typically cause disease
The human genome...
Does not have the coding capacity to have one gene per specific antibody molecule
Opsonization is a process in which antibodies bind to antigens, making the antigens...
Easier to ingest by phagocytes
Effector actions of innate immunity...
Eliminate invaders
In the process of B cell activation, after the BCR has bound the antigen, the cell takes in the BCR and antigen complex via the process of ___
Endocytosis
In the process of directed uptake, the pathogen first attaches to a cell, then triggers the process of ___ that brings it inside the cell
Endocytosis
Tc cell
Endogenous antigen
Peptidoglycan can cause symptoms similar to those that characterize the response to ____. The systemic response leads to septic shock.
Endotoxin
Dendritic cells provide a link between the innate and adaptive immune systems by...
Engulfing material and degrading it, then presenting it to the adaptive system cells
Phagocytosis
Engulfment and digestion of microbes and cell debris
Unlike bacterial cells, viruses must do which of the following to cause disease?
Enter host cells
Dengue hemorrhagic fever
Example of a viral infection where the virus uses binding of antibodies to assist its entry into target cells, rather than being destroyed
TH cell
Exogenous antigen
T/F: Damage caused by inflammatory mechanisms is always directly due to the microbes and the toxic, damaging molecules they create
False
T/F: Monocytes are normally found in various tissues of the human body, including lungs, liver, and brain
False
T/F: Mycobacterium tuberculosis cells direct activated macrophages in the alveoli to ingest them
False
T/F: Serum resistance occurs when bacteria are capable of resisting destruction via the antibody molecules found in blood serum
False - serum resistance is about resistance to complement proteins
T/F: The deeper interior tissues of the body are generally laden with helpful symbiotic bacteria
False - the deeper interior tissues of the body are generally sterile, except during infections
T/F: Macrophages cannot function to eliminate antigen without assistance from helper T cells
False - they can function to eliminate antigen, but they do so more efficiently when they have been activated by helper T cells
Some bacteria have __ receptors on their surface that bind the stem region of antibodies, masking cells from phagocytes
Fc
The constant region of an antibody molecule includes the entire ___ region, but also part of the two ___ regions
Fc; Fab
IgM
First antibody class produced during primary response
Binding of antibodies to ____ interferes with a bacterium's ability to swim. Since movement is often necessary for a pathogen to infect a host, this antibody binding can help prevent infection
Flagella
Fab region stands for
Fragment of antigen binding region
Macrophages and dendritic cells
Function as sentinel cells, engulfing material in tissues and taking it to adaptive immune system cells for inspection
B toxin subunit
Fuse it to a medication
A toxin subunit
Fuse it to compound that will attach to a specific cell type that needs to be destroyed
By forcing cellular neighbors to ___ to form syncytia, viruses can ___ extracellular antibody binding and neutralization
Fuse; avoid
Granulocyte
General term for any type of WBC with noticeable cytoplasmic granules
If activated macrophages fail to destroy microbes, the phagocytes can fuse together to form _______
Giant cells
Purpose of hematopoietic cells
Give rise to WBC and RBC
Proinflammatory cytokines
Group of cytokines that act together to trigger inflammation
One of the traits of IgG molecules that gives them such a strong capacity for productive responses is their long ________-life if 21 days.
Half
Penicillin is a ____, meaning that it can combine with a protein to elicit an immune response
Hapten
Naive lymphocytes
Have antigen-specific receptors, but have not yet encountered the antigen to which they are programmed to respond; mature, but has not encountered antigen previously
Antibody ___ chain gene rearrangement processes are highly similar to those of the ___ chains
Heavy; light
Combinatorial diversity occurs when different fully formed antibody ___ and ___ chains are paired up with each other, yielding different specificities
Heavy; light
CD4
Helper T cell
Fever
Higher than normal body temperature
When MHC class _ levels are shut down on an infected cell by a pathogen, that cell becomes a target for destruction by ___ killer cells
I; natural