Midterm 1 review (CH 1 and 2)
If a person is in a hospital bed for a long period of time without moving, lymph can pool in one spot. This pooling of lymph can become what you know as ______ Pooling of lymph can cause skin damage from swelling, and damaged skin is more likely to break, which increases the chance that a pathogen can enter the body and result in infection .
"bed sores".
Which of the following are characteristics of the innate immune system (check all that apply):
Immune cells are included as part of this branch of the immune system Includes skin and mucosal membranes Is the first line of defense Recognizes many common invaders rather than mounting a specific response to particular invaders Reacts quickly to invaders
Another term for antibodies is:
Immunoglobulin
Macrophages reside:
underneath the epithelial lining of tissues exposed to the environment
Eukaryote
In addition, fungi are eukaryotes, meaning that they have nuclei and other membrane-bound organelles such as mitochondria and the golgi apparatus. The largest invaders our body's immune system needs to be able to handle are parasites.
The primary function of lymph nodes is to:
Increase the chance that B cells and T cells will come into contact with APCs that carry their antigens so that they can be activated
Hyperactivated macrophages (check all that apply):
Increase their rate of phagocytosis Increases the number of lysosomes Produce and secrete TNF Increase their growth rate
Type I interferons:
Inhibit viral replication and activate host defenses Interfere with viral replication by infected cells Alert immune system cells that infection is present Make virus-infected cells more vulnerable to killer lymphocyte attack
MHC I molecules provide information on problems occurring _______ the cell; MHC II molecules provide information on problems occurring _______ the cell:
Inside; outside
A neutrophil makes and stores what protein so that it can rapidly mobilize it to its surface after the neutrophil binds to SLIG?
Integrin
when the PRR's in innate cells such as macrophages detect a virus attack, they produce warning proteins called
Interferon alpha and beta
Interferons and complement proteins contribute to non-specific immunity
Interferons are a group of proteins made by cells in response to viral infection, which induce a generalized antiviral state surrounding cells
Important aspects of the immune system include (check all that apply):
It develops over a person's lifetime Immune cells are mobile Communication between different cells in the immune system is important Communication with other body systems is important
Helper T cells (Th cell) = cytokine factory
It directs the action by secreting chemical messengers that have dramatic effects on other immune cells. Cytokine examples include Interleukin 2, and interferon gamma.
When the C3 complement protein is split, what will happen to the C3b fragment if it does not immediately run into a suitable chemical signal?:
It will be neutralized by a water molecule
Once in the lymph nodes, dendritic cells secrete substances that help the lymphocytes decide what pathway to activate to fight the pathogen.
It wouldn't do much good to mobilize cells that specialize in killing viruses when the pathogen is a large, multicellular parasite.
Three types of T cells:
Killer (aka cytotoxic lymphocytes) T cells Helper T cells Regulatory T cells
The type of cell that destroys virus-infected cells is the:
Killer T cell
Hyperactivation of macrophages is induced by:
LPS or mannose
NK cells can be activated by (check all that apply):
LPS, IFN a and b
All lymphocytes are also ____________
Leukocytes
B cells and T cells differ in which of the following characteristics (check all that apply):
Location where cells mature in the body The types of antigens they can recognize The ability to recognize an antigen whether or not it is "presented" to the cell
B and T cells collectively are called :
Lymphocytes
But there are leukocytes that are not ___________
Lymphocytes
A vesicle inside a phagocyte that contains powerful chemicals and enzymes that can destroy bacteria is called a:
Lysosome
Once there are plenty of C3b on the surface of invader a _______________ forms and anchors within the bacterial membrane
MAC (membrane attack complex)
Antigen presenting occurs via:
MHC molecules
The long-lived cell that resides solely in tissues, is responsible for cleaning up cellular debris, is an antigen presenting cell, and is phagocytic is a/an:
Macrophage
Put the following steps involved getting a blood-borne neutrophil to stop at the sight of infection in order from beginning to end:
Macrophage gives of Il-1 and TNF that signal activation by a pathogen Endothelial cells in blood vessels produce Selectin, which is transported to cell surface Neutrophils bind to Selectin using SLIG which slows them down to a roll Neutrophils look for sure sign of invasion using, like signals called C5a or LPS Neutrophils produce integrin Integrin binds to ICAM Neutrophils stops rolling and enters tissue
A ______ job is to serve as a sentinal that watches for invaders and signals other cells, whereas a ______ job is to be on call circulate in the blood leave the blood at the first opportunity to kill
Macrophage; neutrophil
APC's
Macrophages
The spleen, which is a huge lymph node, has resident ____________ specifically for the purpose of cleaning up dead blood cells.
Macrophages
_______ also engage in antigen presentation, is which a way of showing other immune cells what kinds of invaders it the macrophages have phagocytosed.
Macrophages
MHC 1
Made up of one long chain (heavy chain) plus a short chain (beta microglobulin)
The specialized molecules that "present" an antigen to T-cells are called:
Major histocompatibility complexes
Which compound is found on the surface of cells of a broad array of pathogens but not the cells of humans?
Mannose
lectin activation pathway's central player is a protein produced in the liver that is found in the blood called
Mannose-binding lectin
lectin activation pathway
Mannose-binding lectin binds to bacterial surface carbohydrates to activate the complement. The complement reacts directly with pathogens.
One single B cell produces:
Many copies of the exact same B-cell receptors, all of which recognize the same antigen
One single B cell produces
Many copies of the exact same BCR's, all of which recognize the exact same antigen
________ cells are cells that live in tissues and contain histamines in granules. Histamines are small peptides that act on receptors on the surface of blood cells to cause dilation, or expansion, of blood vessels.
Mast cells
In addition to presenting molecules, MHC's are involved in rejection of transplanted organs and tissues
Matching must be in the MHC molecules of donor and recipient
B cells and T cells that don't die after proliferation are called:
Memory cells; these help us if we are attacked by the same pathogen more than once, often quick enough that you never experiencing symptoms the symptoms again
Immune cells like macrophages are able to recognize invaders by recognizing (check all that apply):
Molecules that are on common the surface of pathogens Signals that our own cells produce when damaged
PRRs recognize :
Molecules that are on entire classes of invaders, such as LPS on gram negative bacteria
When individual genes are picked from gene modules to create an antibody, DNA bases may be added or deleted. This creates:
More antibodies than could otherwise be created, which we call junctional diversity
MHC 1 molecules are produced by:
Most cells in the human body
pDC can make up to 1000 times as much interferon per day as any other cell
Most human cells have receptors on surface for type 1 interferons, if this receptor detects that a virus is in the area, it turns on the expression of several hundred genes that encode proteins that slow viral reproduction it also can warns cell to commit suicide if it gets infected
Which of the following are characteristics of the adaptive immune system (check all that apply):
Mount a highly specific response to particular invaders Needs to be given permission to attack an invader by other parts of the immune system Improves in efficiency upon repeated exposure to the same pathogen Components of this system can develop immunological memory Is a secondary line of defense that is only invoked if needed Immune cells in this system undergo clonal selection Antigen presentation is required to activate this system Takes up to several weeks to mount a full response to invaders Immune cells are included as part of this branch of the immune system
This lineage is associated with the adaptive immune system
Myeloid stem cell lineage
_________ are the most abundant lymphocyte. Puss that you may see from a wound (say, a silver, infected hangnail, or pimple) is actually a collection of all massive amounts of dead ____________that have come to dump their cytotoxic contents to kill a pathogen.
NEUTROPHILS
Cells that use the roll, stop, and exit strategy to get out of the blood include (choose all that apply):
NK cells Mast cells Activated T and B cells Monocytes Neutrophils Eosinophils
Which of the following are lymphocytes (check all that apply):
NKC's, T cells, B-cells, Plasma Cells
Put the following in order (generally) from smallest (1) to largest (4):
virus (non-living), bacteria, fungi, parasite
Which of the following are considered members of the innate immune system (check all that apply):
Natural killer cells Macrophages Neutrophils Skin Complement proteins
Natural killer cells have some characteristics of the innate immune system and some characteristics of the adaptive immune system
Natural killer cells have granules and are able to destroy some parasites, bacteria, virus-infected cells and cancer cells
These cells live only a very short time, with a lifespan ranging from just minutes to a day or so. They live primarily in the blood, but they can migrate out of the blood if they get a signal that indicates they are needed to help in the battle against an invader
Neutrophil
If macrophages get overwhelmed by an infectious agents, they first recruit this kind of cell to help:
Neutrophils
The short-lived cell that resides in the blood, contains granules, is the most abundant leukocyte, and is the primary component in puss is a/an:
Neutrophils
Which of the following are considered white blood cells (check all that apply)
Neutrophils Macrophages Dendritic cells
Bacteria lack which of the following structures:
Nucleus
Cognate antigen
what BCR'S are fishing for. This is the molecule with the correct Fab region that a BCR can grab onto
Toll-like receptors are a family of patter-recognition receptors can be located (check all that apply):
On the outer surface of phagocytic cells In the membranes of phago-lysosomes
An individual antibody binds to
One specific antigen
An individual antibody binds to:
One specific antigen
When an antibody binds to an invader, the antibody has:
Opsonized the invader
Immunologist say that antibodies can ________ invaders by "decorating" invaders this means.....
Opsonizing; they bind to the invader with their Fab region, leaving their Fc tails available to bind to Fc receptors on the surface of cells such as macrophages
2 primary properties of PRR's
PRR recognize general characteristics of classes of invaders (not single invaders) 2nd important characteristic of the patterns which PRR's recognize is that they represent structural features which are so important to the pathogen that they cannot easily be altered by mutation to avoid detection
The type of immunity that results when a person receives antibodies to an invader from another individual who had been exposed to a pathogen is called:
Passive immunity
NKC use an injection system that uses ______ proteins to deliver suicide enzymes (granzyme B) into the target cell. In other situations a protein called _____ on the NKC cell surface interacts with a proteins called Fas on the surface of its target, and causes the invader to self-destruct.
Perforin; Fas Ligand
During phagocytosis, the phagocyte ingests a potential invader and the resulting vesicle containing the invader is called a:
Phagosome
The king of interferons is the
Plasmacytoid dendritic cell (pDC)
Platelets are not cells but are fragments of megakaryocytes.
Platelets also secrete factors that aid in healing and tissue repair. The red blood cells make up a large portion - almost 40% - of our blood. Platelets are structures that promote clotting when your blood vessels are damaged and you are bleeding.
Myeloid stem cells give rise to :
Platelets and erythrocytes (RBC's, platelets,
IFN-g causes macrophages to (check all that apply):
Produce and display more MHC II molecules Feed more vigorously
After a BCR finds its cognate antigen, it can now _______
Proliferate (aka it is triggered to double in size and divide into two daughter cells. Resulting in about 20,000 identical B cells. A real defense can now be mounted.
When a B-cell receptor binds to its cognate antigen, it is induced to double in size and divide into two daughter cells. This process is called:
Proliferation
IFN-a and IFN-b are best described as:
Proteins that can ready cells for possible viral attack
Activation of a Helper T cell
Recognition of cognate antigen and the most common receptor on the surface of a helper T cell is CD28 Non-specific signal proteins on surface of antigen (the most common "non-specific signal protein" on the surface of an APC is the protein called B7)
The method by which the 4 different gene modules are combined to make an antibody is called:
Recombination?
The only cell listed below that is not a leukocyte is the: T cell Dendritic cell Red blood cell Macrophage Basophil B cell Eosinophil Neutrophil Monocyte Natural killer cell
Red blood cell
Macrophages have 3 stages
Resting (function primarily as garbage collectors, expressing very few MHC 2 on their surface, so they aren't very good at presenting antigen to helper T cells in this phase) Activated (in order to be primed the macrophage receives is a cytokine called interferon gamma (produced by helper T and NKC's) This causes the macrophage to up-regulate expression of class 2 MHC molecules and function to be a better APC) Hyper-activation (this phase is activated by receiving a signal from an invader called LPS (LPS is found on the outside of harmful bacteria) this process of binding is certain way to tell the macrophage that an invader is within. This causes proliferation and increases rate of phagocytosis. Another cytokine macrophage can produce is called TNF which kills tumor cells and virus-infected cells and activates other immune cells to kill invader
Macrophages exist in three stages :
Resting, primed and hyperactivated
Which of the following are constitutively (always) expressed on the surface of neutrophils:
SLIG
Having such a complicated process protects our bodies from the powerful destruction of neutrophils. This process ensures that the attack is real and the need for neutrophil destruction is apparent
Safety measure
Activated macrophages give off cytokines, including IL-1 and TNF, to signal an invasion. In response to these signals, the endothelial cells on the walls of blood vessels begin to express what protein:
Selectin
Resting NKC's produce some cytokines and can kill, but kill better if they are activated
Several signals that can activate NKC's include IFN alpha and IFN beta In addition, when their surface receptors encounter LPS they can be activated
The first line of defense against potential pathogens is:
Skin and mucous membranes
Complement can be used against (check all that apply)
Some viruses Bacteria parasites
Steps in activation of Helper T cell requires 2 steps:
Specific recognition of its cognate antigen (usually as a protein fragment being displayed by class 2 MHC molecules on the surface of an APC) Non-specific involves a protein on the surface of an APC that plugs into its receptor on the surface of the Th cell.
Put the following steps in the life cycle of a macrophage in the correct order, from beginning to end:
Stem cell differentiates into monocytes Monocytes leaves bone marrow and enters blood stream Monocyte travels to the capillaries Monocyte leave blood vessels and enters tissues through cracks in endothelial cells Monocyte matures into macrophages
T (thymus) cells have surface proteins called
T Cell Receptors (TCR's)
The cytokine that can kill tumor cells and virus-infected cells is:
TNF
Which of the following best describes the relationship between the DNA in immature B cells and the DNA in mature B cells:
The DNA of all immature B cells are identical to one another, but the DNA of mature B cells is different from the DNA in immature B cells
The cells in the myeloid lineage are generally associated with the innate immune response. This is made up of 3 cells called the:
The basophils, neutrophils, and eosinophils are called granulocytes
Plasma is the
The component of the blood that contains water, proteins, nutrients, and hormones
Complement proteins are produced primarily in:
The liver
Neutrophils are (check all that apply):
The main constituents in puss Short-lived Cytokine producers Phagocytic cells
RBC's
The red blood cells make up a large portion - almost 40% - of our blood.
The most well studied PRR is the TLR's (10 human types of known)
These are displayed on that outside of cells (TLR4 which is anchored on the plasma membrane and sense bacterial invaders in the external environment) or inside of cell (that alert the cell to the presence of viruses or bacteria that have been phagocytized)
Two keys required for activation because:
These cells are powerful weapons and we only want to activate appropriately
eosinophil granules contain neurotoxins that can cripple the nervous system of multicellular parasites.
These cells live in blood but migrate to tissues when they get signals from the inflammatory response. These cells also live only minutes to days, and their goal is to destroy pathogens or elements of their structure.
What conditions might cause neutrophil abundance to be too low?
These could include having had chemotherapy or radiation, or having cancer of the bone marrow, which produces the precursors to neutrophils.
The immune system targets 4 main classes of pathogens
These include bacteria, viruses, fungi, and larger parasites
There are killer (or cytotoxic) T cells, helper T cells, and regulatory T cells.
These serve to kill pathogens directly help other immune cells be more effective and regulate the immune system's activity.
they do not try to survive - their mission is to empty their granules in a process called degranulation. This contributes to the fact they neutrophils are so short-lived.
They sacrifice themselves for the purpose of killing pathogens. This makes neutrophils the most powerful immediate response we have to invaders.
Macrophages are long-lived surveillance cells.
They "look" for infections organisms or signals of infection given off by your own infected cells, like sentries on watch.
Basophils
They are also designed primarily to deal with parasites. But in addition, they also contribute to allergy by releasing histamines.
Which of the following are true about INF-a and INF-b (check all that apply):
They are can be used to warn cells about a range of viruses They are secreted by infected pDCs
Eosinophils
They are designed primarily to deal with larger parasites. The granules of eosinophils contain digestive enzymes that break down your own collagen matrix. For example, say you have ingested a worm that is an intestinal parasite. That worm wants to hook into your intestinal wall and stay for a while. Eosinophil granules contain collagenases, which can break down the collagen matrix that would allow the worm to attach to your intestinal wall.
Granulocytes
They contain granules packed with potent killing compounds, which can be released in order to damage or kill potential pathogens. These three types of cells all contain granules and have nuclei that contain multiple lobes rather than the typical single round nuclei. Their names also all end in "phil" -
Macrophages do not ______
They do not migrate out of tissues once they have matured.
Clonal selection cont'd: If a B cell makes a catch and attaches its cognate antigen, it proliferates and clones about 20,000 copies of itself, eventually producing a great quantity of antibodies to mount a defense against pathogen
This is a great design because: B cells use relatively few genes to create enough different antibody molecules to recognize any invader B cells are made on demand so we don't have a ton of useless cells circulating at any given time after the cline of a B cell has grown sufficiently large, most of these cells become antibody factories which create huge amounts of antibodies that are exactly right for the pathogen When the intruder has been conquered most of the B cell dies
The lymphocyte lineage contains T-cells, B-cells, and natural killer cells:
Together, these three classes of cells are known as lymphocytes. Note that the term "lymphocyte" refers to these three classes of cells that are part of the adaptive immune system. All lymphocytes are also leukocytes.
The concept that describes immune cells being "educated" so they don't attack our own cells and attack only those of invaders is called:
Tolerance to self
There are leukocytes in both the myeloid and lymphoid lineages.
True or False
Activation of the helper T cell requires:
Two steps: the binding of the T-cell receptor to its cognate antigen, and the binding of the T-cell's CD28 receptor to the B7 protein on an activated APC
B cells and T cells share which of the following characteristics (check all that apply):
Use modular design to create a diverse array of antigen-binding receptors Produced in the bone marrow Undergo proliferation via clonal selection once they bind to an antigen Have cell-surface receptors that can bind to specific antigens
NKC's mature in bone marrow and are found in blood or spleen and liver and very few are in the tissue if they are not under attack
Use the roll stop exit strategy to enter tissues if they need to. Once in tissue they proliferate. Once they reach the tissues they can give off cytokines including IFN gamma that help with defense.
In every B cell (on the chromosome that encodes for the antibody heavy chain) there are multiple copies of 4 types of DNA modules (aka gene segments) called:
V, D, J and C
The 4 different gene modules that are combined to make an antibody are called:
V, D,J,C
The Fab region of an antibody (check all that apply):
Varies from one antibody to another Binds to an antigen
Monocytes circulate only in the blood. However, when they leave the blood, they mature into one of two types of cells:
a macrophage or a dendritic cell These cells are both phagocytic and they are also both antigen-presenting cells Monocytes are essentially the immature progenitor cells that can differentiate into either dendritic cells or macrophages
Opsonizing targets allows them to form a bridge between the invader and the phagocyte which allows them to prepare
and bring the invader closer for phagocytosis.
B cells, and more specifically plasma B cells, are the cells that produce _________ against a potential invader
antibodies
Classical activation is dependent on
antibodies for activation
Y-shaped proteins that are made in response to exposure to a particular antigen and secreted into the blood are called:
antibodies or immunoglobulins
BCR's
are formed after B cells creates antibody molecules, these are transported to the surface of the b cell and tethered with their antigen-binding regions facing out. Each B cell has 100,000 BCR's on its surface. ALL BCR'S ON A GIVEN B CELL RECOGNIZE THE SAME ANTIGEN
Secondary lymphoid organs
best of which is known as a lymph node
MBL works to activate the complement system by binding in blood to MASP protein and when MBL finds its target MASP protein functions like a convertase to clip C3 into C3b. These then
bind to the surface of pathogen and can begin to create a MAC complex which will help destroy the pathogen
Immune and blood cells originate in
bone marrow
Like B cells, T cells are produced in the
bone marrow
Most abundant of the proteins is called ___
c3 (convertase) and are continuously being broken down into smaller proteins
Monocytes are cells that _________ . When monocytes mature, they can become either ________ or ________ , which ________ .
circulate in blood; dendritic cells or macrophages which live in tissue
During times of no viral infection NKC's
circulating in the blood, spleen or liver
Each B cell has 100,000 BCR's tethered to the outside of cell and all of the BCR's recognize the same antigen ,waiting for their
cognate antigen
PRR's recognize
danger signals associated with pathogen invaders PRR's detect 2 types of patterns: Pathogen associated molecular patterns (PAMP's) Damage associated molecular patterns (DAMP's)
__________ are the only cells to purposefully travel to the lymph in order to take their antigen message to the hubs that are lymph nodes.
dendritic cells are cells that serve as communicators between the innate and adaptive immune systems. Dendritic cells present their antigens to T cells in order to activate the adaptive immune response when necessary.
Antibiotics that inhibit the synthesis of peptidoglycan, such as those in the penicillin family tend to be more effective against ______ bacterial cell walls than _______bacterial cell walls.
gram positive; gram negative
Neutrophils can be thought of as explosive packages full of______________ . Their goal is to eliminate invading cells by unleashing their cellular weaponry.
invader-destroying enzyme
Neutrophils
make up 70% of circulating WBC's Can turn tissue into toxic soup to kill invader can liquify tissue connective tissue and cells Leave blood stream to kill invaders in tissues
Killer T cells destroys by:
making contact with its target, and then triggering the cell to commit suicide. This is great because when a virus infected cell dies, the virus within the cell dies too.
Which of the following cell types do not mature until they get to the tissues (check all that apply):
mast cells, macrophages and dendritic cells, and B and T cells.
A special cell that can differentiate into a wide variety of cell types is called a
multipotent hematopoietic stem cell
alternative pathway of complement activation
one of three pathways of complement activation. It is triggered by the presence of infection but does not involve antibodies The early stages leading to cleavage of C3 involve iC3b, factor B, and factor D. This results in a C3bBb molecule forming and can help create more (+ feedback) Ultimately meant to attack hydroxyl groups and amino groups on the surface of pathogens Accelerants to stop this process in order to prevent it from destroying our cells are: MCP enzyme that is present on surface of human cells prevents attachment DAF destruction on Convertase CD59 is called protectin prevents the incorporation of C9 into nearly MAC's
Cells most associated with type I interferon production are:
pDC
Put the following steps used by pDCs to warn other cells of a potential viral invader in order from beginning to end:
pDC cells become infected with virus pDC cell releases IFN alpha and IFN beta Human cells that have the IFN a and IFN b receptor bind, and IFN ligand bind, thus warning the cell Human cells produce proteins that slow viral reproduction causes warned cell to commit suicide if infection; if not infected, business as usual
Gram-positive bacterial cells contain a very thick layer of
peptidoglycan (a series of linked sugars and amino acids), which serves as additional protection for the bacteria. In addition, sticking out from the outermost surface of the cell wall is a polymer called teichoic acid, which is common to most grampositive bacteria.
Gram-negative bacteria also contain
peptidoglycan, but the layer is much less thick than that of gram positive bacteria. However, gram negative bacteria have second plasma membrane, called the outer membrane, for additional protection. On the outermost surface of the cell wall of gram negative bacteria is a lipid-sugar molecule known as lipopolysaccharide, or LPS.
Put the following steps of phagocytosis in correct order, from beginning to end:
phagocyte senses invader and moves towards it phagocyte engulfs invader Phagosome fuses to lysosome Lysosome releases digestive enzymes Digestive enzymes destroy invader
In addition, notice that mast cells do not share the same ___________ cell as the other granulocytes.
progenitor cell
Once activated :
proliferation of many clones that recognized the same antigen These Th cells then mature into cells that can produce cytokines needed to direct the activities of the immune system
Some cells, become fully differentiated in the bone marrow and enter the blood as mature cells. These cells include the
red blood cells, all 3 granulocytes of the myeloid lineage, and natural killer cells.
Think PEPTIDOGLYCAN POSITIVE
remember
This unique capability of stem cells make daughter cells that continue to be stem cells is called:
self-renewal
Complement system is composed of about _____ proteins
20
In a normal healthy person, there are _______ individual B cells that can produce an antibody that binds to any one specific antigen. _________ is the process by which additional copies of a particular B cell can be to counteract a specific invader with antigens that bind to a particular antibody.
3 billion; clonal selection
Adult humans have _____ killer T cells
300 billion
If a person has fewer than _____ neutrophils pre milliliter of blood, they will need to be placed in isolation because they are missing their most potent early line of defense.
500
Purpose of the immune system
A complex of network organs, tissues, cells and molecules that work together to protect the body against foreign invaders
Interferon gamma (or IFN-g) is: (check all that apply):
A compound that can activate a resting macrophage to the primed state Produced mainly by helper T cells and NK cells a cytokine a protein
Medically important gram negative bacteria
A few examples of medically important gram-negative bacteria include those that cause food poisoning, typhoid fever, dysentery, the plague, pneumonia, sepsis, and gangrene.
Medically important gram positive bacteria
A few examples of medically important gram-positive bacteria include those that cause staph infections including MRSA, strep throat, diphtheria, listeriosis, and botulism.
Neutrophils are an integral part of our inflammatory response. So, these cells are our primary front-line mechanism for killing invaders
A person cannot live without neutrophils. Our bodies have to make neutrophils every day. We usually expect to have ~4150 neutrophils per microliter of blood.
The complement cascade is an example of
A positive feedback loop
All viruses contain (check all that apply):
A protein capsid DNA or RNA genes
NKC's destroy tumor cells, virus infected cells, bacteria, parasites, and fungi
ALL BY FORCING THEM TO COMMIT SUICIDE
MHC II molecules are produced by:
APC's
The type of immunity that results when a person's own immune response is induced from exposure to a pathogen is called:
Active
The type of immunity that results when a person receives immune cells from another individual who had been exposed to a pathogen is called:
Adoptive
Clonal selection
After B cells go through their mix and match process of modular design and junctional diversity, they produce a heavy chain and light chain, and small number of these end up as the B cell receptor and are transported to the surface of the cell.
Class 2 MHC molecules
Also function as billboards, but this display is intended to inform the helper T cell Only certain cells make these MHC's, they're called Antigen presenting Cells and they inform helper T cells that a problem exists outside of cells (displayed after a macrophage engulfs a virus or bacteria)
Although histamine production is the hallmark function of mast cells, these cells can also be important in amplifying inflammatory signals to help recruit other immune cells to the site of infection.
Although mast cells do have granules inside them, we do not think of these as typical granulocytes, because granulocytes live in blood, not tissues.
There are about 3 billion B cells in bloodstream and this is possible due to their being about 100 million kinds of B cells. This means that no average we have about 30 B cells in the blood that can produce antibodies which will bind to a given antigen.
Although this is true, we don't have a lot of any kind of B cell at a given time, as a result we must produce more B cells on demand if we are attacked, this is through a process called clonal selection.
The main difference between an antibody and a B-cell receptor is:
An antibody is secreted outside the B-cell and the B-cell receptor is anchored to the surface of the B-cell
The condition in which your body has too little hemoglobin is called:
Anemia
The term that describes the chemical component (i.e., ligand) to which an antibody binds is:
Antigen
leukocytes are white blood cells that
stem from both the myeloid and lymphoid stem cells
Antibodies jobs are to plant the "kiss of death" not to actually kill, this is done by:
tagging an invader for destruction by other immune cells
Molecules on the very outer surface of the cell walls can be used by your immune system to recognize specific kind of invader that you are experiencing. _______ is the outer surface molecule associated with gram positive cell walls, and __________ is the outer surface molecule associated with gram negative cell walls.
teichoic acid; LPS
Virus lifecycle steps in order :
Attachment Penetration Uncoating Biosynthesis Assembly Release
NK cells use the balance of "kill" and "don't kill" signals on the target cell's surface to determine whether or not to kill a particular target cell. The "kill" signal is _____________ and the "don't kill" signal is __________
Atypical carbs or proteins; MHC 1 molecules
After a B cell proliferates, most of the cells now begin to make antibodies and these antibodies travel to ....
the blood stream, and the B cell that produced them usually dies. After this, these antibodies are certain to be useful against invader. Following this production and after the invader has been conquered, these B cells usually die. This process ensures that we don't become filled with B cells that that were used for yesterdays invader, and instead we can create more for tomorrow's attacker
Inside lymph nodes:
B and T cells circulate form node to node looking for the antigen for which they are fated. Lymph nodes are a place where T cells, B cells, APC's and antigens all gather for the purpose of communicating and activation
You only need to know that the initial commitment to a particular cell line and some degree of development occurs in
the bone marrow
Antibodies are produced by:
B cells
Put the following steps involved in clonal selection in order from beginning to end:
B cells attach antibodies to their cell surface, turning the ab's into BCR's B cells circulate in the blood looking for their cognate antigen BCR's bind to their cognate antigen Proliferation of selected B cells occurs Plasma B cells produce antibodies Antibodies released into blood stream Plasma B cell dies
Differences between B and T cells
B cells mature in bone marrow, T cells mature in the thymus Although B cells make antibodies that can recognize any organic molecule, T cells specialize in recognizing protein antigens A B cell can secrete its receptors in the form of antibodies, but a T cells receptor remain tightly glued to its surface A B cell can recognize an antigen by itself, but a T cell will only recognize recognize an antigen if it's presented by another cell
An antibody that has been tethered onto the surface of a B cell is called a
BCR
TCR's are made by the same mix and match modular design strategy which makes them as diverse as
BCR's
Prokaryote
Bacteria are the smallest of the living organisms. They are prokaryotes, meaning they have no nucleus in their cells and no other membrane-bound organelles.
Which of the following potential invaders are considered living? (check all that apply):
Bacteria, fungi, parasites
These cells live in the blood, and they are the least common of all of the leukocytes. Their lifespan in unknown, and these cells are not as well-studied as other kinds of immune cells.
Basophils
just remember that the adaptive immune response cannot be initiated in the absence of an innate immune response.
Because the adaptive immune response is very specific, and mounting an adaptive immune response is energetically costly. We only want to activate the adaptive immune response if we are sure that the threat is real.
The Fc region of an antibody (check all that apply):
Binds to the Fc receptors on the surface of immune cells Determines the class of antibody (i.e., IgA, IgG, etc)
A neutralizing antibody is one that:
Binds to viruses so that the viruses cannot enter your cells and take advantage of your cells (by using your cells machinery to make many copies of itself)
Red blood cells are formed in the:
Bone marrow
The component of the blood that contains leukocytes and platelets is the:
Buffy coat
Put the following steps involved in in the complement cascade in order from beginning to end for a bacterial invader:
C3 gets close to a bacterial cell C3 is spontaneously clipped into C3a and C3b C3b is stabilized by reacting with with a hydroxyl group or amino group on surface of bacterial cell B proteins binds to C3b In the presence of protein D, protein B cleaves C3b to yield C3bBb C3bBb molecule called convertase clips additional C3 molecules into C3b 2 molecules of C3b clip C5 into two pieces C5b combines with complement proteins C6, C7, C8 to form a stalk that anchors the complex C9 is added to make a channel that punches a hole in to the membrane of the pathogens cell wall
Proteins that serve as chemoattractants include: (check all that apply)
C5a C3a
Once a neutrophil has stopped, it knows to move out of the blood and into the tissue by looking for signals including:
C5a and f-met
Proteins that human cells use to ensure that complement proteins do not form MACs in our own cells include: (check all that apply)
CD59
The protein that prevents C9 from being incorporated into MACs is:
CD59
Macrophages cannot swallow large parasites. They therefore:
Can dump the contents of their lysosomes outside their cell to harm parasites
Immunology includes the study of how our bodies respond to (check all that apply):
Cancer Bacteria Parasites Allergens Viruses Toxins Autoimmune conditions
For these cells, the precursor cells circulate in the blood, and maturation to fully committed, mature, cells only occur after the precursor cells leave the blood and enter the tissues, these include :
Cells with this development pattern include mast cells, macrophages and dendritic cells, and B and T cells.
Which of these types of proteins cross the entire plasma membrane, with part of the protein on the inside of the cell and outside of the cell:
Channel proteins Transmembrane protein
During times of no viral infection, NK cells reside:
Circulating in the blood or in the spleen and liver
Two types of MHC molecules
Class 1 MHC molecules Class 2 MHC molecules
The molecules used by antigen-presenting cells that present antigens from invaders helper T cells are called:
Class 2 MHC proteins
The molecules that present viral peptides from cells infected with a virus to cytotoxic T cells are called
Class I MHC proteins
This system must be activated before it can function and there are three ways this can happen:
Classical pathway Alternative Pathway Lectin activation pathway
When a TCR binds to its cognate antigen, the T cell proliferates to build up a clone of T cells with the same specificity, it obeys the same type of
Clonal selection as B cells do
complement proteins
Complement proteins are proteins that lyse the cell wall of an antigen. They are part of the nonspecific defense mechanisms of the immune system.
Which of the following statements are true about complement: (check all that apply)
Complement proteins can to opsonize, or tag, cells for destruction by other members of the immune system, such as phagocytes The complement cascade is fast-acting Human cells need to be protected from the effects of complement Complement is part of the innate immune system Complement proteins can act as attractants to alert immune cells to the location of a pathogen The complement cascade can be activated by the classical pathway The complement cascade can be activated by the lectin pathway The complement cascade can be activated by the alternative pathway
There are two main lineages of blood cells:
the myeloid lineage and the lymphoid lineage
Proteins that are secreted by macrophages (and other immune cells) to communicate with other cells are called:
Cytokines
The broad class of molecules whose purpose is communication among different cells are:
Cytokines
The protein that causes the C3bBb convertase to degrade quickly when near human cells is:
DAF
there are two cell types that cross-talk between the systems or have characteristics of each system
Dendritic Cells and Natural Killer Cells
The _________ serves as a communication bridge between the innate and adaptive immune systems, and the __________ has some characteristics of innate immune system cells and some characteristics of adaptive immune system cells:
Dendritic Cells; Natural Killer Cells
The long-lived cell that resides in tissues and can migrate to the lymph node, where it presents antigens is a/an:
Dendritic cells
dendritic cells are unique among all leukocytes it that they serve as a bridge to pass information from the innate immune system to the adaptive immune system.
Dendritic cells are part of the network of sentries in tissues, and once they sense a pathogen, phagocytose it, and present the antigen on the outside of their cells, they can actively migrate to the lymph node where they will take their message about the specific nature of the pathogen to adaptive immune cells.
Like macrophages, dendritic cells also originate from monocytes after monocytes leave the bloodstream
Dendritic cells have many long, narrow projections, called dendrites. These projections increase the surface area of the cell, which improves the dendritic cells' ability to sense invaders or chemical signals from injured cells. primary function of dendritic cells is that they are able to display antigen fragments on their cell surface, and then they are able to move to local lymph nodes to activate the adaptive immune system.
This MAC forms a hole in the surface of bacterium that ultimately ___________
Destroys it
NKC do not have T cell receptors, instead they have receptors that activate or inhibit
Don't kill signal is conveyed by class 1 MHC molecules on the surface of a potential target Kill signal is conveyed by unusual carbohydrates or proteins on the surface of target cells and act as flags
dendritic cells
these cells live in your body tissues and wait like a soldier on watch for chemical signals from injured cells or pathogens. They then migrate from the tissues to lymph nodes via the lymphatic vessels, taking information with them about the nature of the invasion. dendritic cells serve as messengers, and when they take their message to lymph nodes, the B and T cells of the adaptive immune system respond. So, dendritic cells serve to connect the innate immune response to the adaptive immune response.
Short-lived cells that resides in the blood, contains granules, and are primarily responsible for mounting a response to parasites are (check all that apply):
EOSINOPHIL BASOPHIL
Other cells that leave blood and enter tissue
Eosinophil Mast cells (both of which are parasite protection) Monocytes (to become a macrophage or dendritic cell) Activated T and B cells
Macrophages in the resting stage (check all that apply):
Express few MHC II molecules on their surface Phagocytose dead cells Are inefficient at antigen presentation
Fab region of an antibody is composed of light chains that can bind to :
F A (antigen) b(binding) region
Put the following steps involved in opsonization in order from beginning to end:
Fab region of on antibody attaches to the its cognate antigen on an invader Fc region of an antibody binds to the Fcr region of a phagocytic cell Phagocytic cell becomes even more phagocytic invader is phagocytized
We need about 100 million antibodies to protect us
this is possible because of
The portion of an antibody that binds to an antigen is called the:
Fc region
What region determines the class of the antibody?
Fc region
The portion of an antibody that binds to receptors on the surfaces of immune cells is called the:
Fc region. Binds to receptors on the surface of cells such as macrophages.
To assemble a mature heavy chain gene, each B cell chooses one of each kind of gene segment and pastes them together. There are a huge amount of variation in each segment, so there is no prob creating 100 mill B cells each with the ability to create different antibodies to protect us.
this is possible through junctional diversity and modular designs
Which of the following are characteristics of the lymphatic system (check all that apply):
Fluid is not pressurized Fluid from the lymph eventually is returned to the blood supply Fluid moves from your legs to your torso via muscle contraction and one-way valves Fluid comes from liquid that leaks out of blood vessels
Antibiotics and gram positive
For example, some antibiotics, like those in the penicillin or cephalosporin families, inhibit the synthesis of peptidoglycan. Peptidoglycan is really the only form of protection outside of the plasma membrane for gram positive bacteria, so antibiotics like these have a large effect on gram-positive bacteria.
NK cells kill other cells primarily by:
Forcing infected cells to commit suicide
Class 1 MHC molecules
Found of the surface of most body cells Function as billboards which inform killer t cells about what is going on inside of cell when a cell is infected, fragments of viral proteins called peptides are loaded onto the MHC and transported to the surface of the infected cell so that the killer T cell can use this to "see" inside the cell and make it commit suicide
Which potential invaders are considered eukaryotes (check all that apply)?
Fungi and parasites
Fungi have
Fungi have cell walls that are made of the chitin, or chitosan, which is the same type of molecule that occurs in the shells of crabs and shrimp.
Fungi
Fungi, like all cells, have a cell membrane, but they lack the peptidoglycan cell wall structure of bacteria. The cell walls of fungi also include structural polysaccharides and glucans. These compounds, along with the glycoproteins that stick out of the exterior surface of the cell wall, are indicators to our immune systems that we have a fungal infection.
so remember that the "phils" are the granulocytes
GRANULOCYTES-PHILS
Which kinds of organisms contain peptidoglycan in their cell walls (check all that apply):
Gram negative and gram positive bacteria (the gram positive bacteria have a thicker peptidoglycan wall layer)
bacterial cell walls contain a very thick layer of peptidoglycan, and bacterial cell walls contain thin layer of peptidoglycan and also contain and extra cell wall called the outer membrane
Gram negative bacteria
Antibiotics and grab negative bacteria
Gram-negative bacteria, on the other hand, have the additional protection afforded by their outer membrane, so drugs designed to inhibit peptidoglycan synthesis do not affect gram-negative bacteria as severely as they do gram-positive cells. The differences in cell wall structure also result in different abilities to cause disease. For example, the LPS found in gram negative bacteria is extremely immunogenic in animals, meaning that it elicits a very strong immune response. When our immune systems sense LPS, they produce chemical factors that eventually lead to development of fever. Simplistically, you can think of gram-negative bacteria as having a thin bulletproof vest.
MHC 2
Have 2 long chains (Alpha and beta)
Regulatory T cells
Help keep the immune system from overreacting- not fully understood
The type of T cell that secrete chemical messages among immune cells to coordinate the immune response across different cell types is the:
Helper T cells
Which of the following cells have to be "activated" by a two-step activation system (check all that apply):
Helper T cells
Hematocrit is calculated by dividing the volume of the red blood cells, indicated here as "A", by the total volume of blood, indicated here by "B"
Hematocrit comprises about 40-60 % of total blood volume
Which class of organism contains plasma membranes (or cell membranes) surrounding their cellular contents (check all that apply):
Humans Fungi Parasites
Which chemical groups are able to initiate the complement cascade (check all that apply):
Hydroxyl group, and amino group
Integrin on the surface of a neutrophil binds to what protein on the endothelial cells of blood vessels to stop a neutrophil from moving:
ICAM
Which of the following are constitutively (always) expressed on endothelial cell walls of blood vessels:
ICAM
On endothelial cell walls of blood vessels _________ is constitutively (always) expressed whereas __________ is only expressed when IL-1 and TNF signal an invasion nearby. On the cell surface of neutrophils, ____________ is constitutively (always) expressed whereas ____________ is only expressed after the neutrophil binds to selectin.
ICAM; selectin; SLIG; integrin
If a cell surface is not protected it will be attacked by complement
IT works like little grenades that drop bombs to kill
In general, the function of an antibody is to:
Identify bacterial and viral invaders so other immune system components can kill them
