Chapter 16

Activation of complement and inflammation: -Stems of two or more Ig_ antibodies bind to complement protein 1 (C1) activating it to become enzymatic. This begins the classical _____ pathway, which releases inflammatory mediators. -IgE binding to epitope and mast cells and eosinophils triggers the release of ____ chemicals

M complement inflammatory

_____ includes: the appendix lymphoid tissue of the respiratory tract vagina urinary bladder mammary glands Peyer's patches in the small intestine -most of the body's lymphocytes

MALT

_____ bind to antigens and trigger adaptive immune responses

Lymphocytes

_____ T lymphocyte - represses adaptive immune responses and prevent autoimmune diseases

Regulatory

How are virus-infected cell and antigen-presenting cell presentation similar? a) Antigens are displayed on the surface of the cell. b) Both involve phagocytosis. c) Both cells are infected with a pathogen. d) Both cells digest engulfed bacteria for antigen processing.

a

How do the cells of the immune system detect internal proteins without entering the cell? a) The proteins are processed and displayed on the cell surface of MHC proteins. b) The proteins are secreted directly from the cell to the immune cell. c) The immune cells take peptides 8-10 amino acids long directly from the cytosol of the cell. d) The proteins are processed and displayed on the cell surface by the endoplasmic reticulum.

a

Five attributes of adaptive immunity: Adaptive immunity does not act against normal body cells

Unresponsiveness to self

Once bound, antibodies function in several ways. These include: (5)

activation and complement of inflammation neutralization opsonization agglutination anti-body dependent cytotoxicity

The major function of the descendants of B cells is to secrete soluble _____

antibodies

____ are free immunoglobulins and are similar to BCRs in shape

antibodies

protective proteins secreted by descendants of B cells

antibodies

Every T cell has a different shaped _____-binding site that recognizes and binds to a complementary shape

antigen

Structure of a B cell receptor (BCR): Together the two variable regions, one at the end of each arm of the Y, form ____ sites

antigen binding

Exact binding between the ____ site and ____ accounts for the specificity of an antibody immune response.

antigen binding epitope

Properties of Antigens: The body recognizes antigens by the 3-D shapes of regions called epitopes, or _______

antigenic determinants

Adaptive immune responses are directed against portions of cells, viruses, and even parts of single molecules that the body recognizes as foreign and worthy of attack These biochemical shapes are known as ________

antigens

the molecules that trigger adaptive immune responses

antigens

Clonal Deletion of T Cells cont.: -The result of clonal deletion is that surviving lymphocytes respond only to foreign _____ -This process occurs in the ____ and takes about 1 week

antigens thymus

Anti-dependent cytotoxicity is similar to opsonization in that antibodies cover the target cell; however, with ADCC the target dies by ____, whereas with opsonization the target is _____.

apoptosis phagocytized

Clonal deletion of T cells: Every population of maturing T lymphocytes includes numerous cells with receptors complementary to normal body components, or ____antigens; however, the immune system must be tolerant of "self"

auto

Types of Antigens: Antigenic molecules derived from normal cellular processes are ______.

autoantigens

The body eliminates self reactive lymphocytes via clonal deletion -Lymphocytes are exposed to _____ -Those lymphocytes that react to autoantigens undergo ___

autoantigens apoptosis

How do immune system cells identify virus-infected cells? a) change in cell morphology b) presentation of viral antigens by the infected cell c) presentation of viral antigens on a noninfected antigen-presenting cell d) presence of viral nucleic acid in the nucleus

b

What does MHC stand for? a) major histone complex b) major histocompatibility complex c) minor histocompatibility complex d) major histocompatibility core e) minor histone core f) major histone core

b

Why is antigen presentation needed if a normally functioning immune system is available? a) Antigens are essential for cell survival b) Pathogens can evade the immune system, requiring cells to signal to the immune system that they are infected. c) Antigens are important metabolic end products. d) Antigen presentation does not occur in a normally functioning immune system.

b

Neutralization: -Antibodies can ____ to a critical portion of a toxin or can ___ adhesion molecules on the surface of a bacterium or virus -Toxin can/cannot? function and pathogen can/cannot? adhere to target cell

bind block cannot cannot

Which of the following cells will have Class II MHC proteins? a) skin cells b) intestinal epithelial cells c) dendritic cells d) smooth muscle cells e) red blood cells

c

When antigenic epitope binds to its unique BCR, B cell undergoes ____, giving rise to nearly identical offspring that secrete immunoglobulins into blood or lymph -Immunoglobulins act against the ___ that stimulated B cell

cell division epitope

Five attributes of adaptive immunity: Once introduced, cells of adaptive immunity proliferate to form many generations of nearly identical cells, which are called clones

clonality

Properties of Antigens Examples of ______: -components of bacterial cell walls -capsules -pili -flagella -viral proteins -fungal proteins -protozoal proteins -toxins -some nucleic acid molecules

complex molecules

Antigen processing would involve which of the following for antigen-presenting cells? a) degradation of a whole bacterium into smaller, more presentable particles b) engulfing of a foreign bacterium c) movement of the small digested particles to the cell surface d) all of the above

d

Which of the following would you likely see on the surface of a human macrophage following phagocytosis of a bacterium? a) Class I MHC with macrophage antigens b) Class II MHC with engulfed bacterial antigens c) Class II MHC with macrophage antigens d) # 2 and # 3 e) #1 and #2 f) all of the above

e

Five attributes of adaptive immunity: Cells of adaptive immunity are activated in response to the specific pathogens

inducibility

Cell-Mediated Immune Responses: Responds to intracellular/extracellular? pathogens and ____ body cells

intracellular abnormal

T cells circulate in the lymph and blood and migrate to the ______, spleen, and Peyer's patches -Account for ___-___% of all lymphocytes in the blood

lymph nodes 70-85

Five attributes of adaptive immunity: For specific pathogens; it adapts to respond faster and more effectively in subsequent encounters with a particular type of pathogen or toxin

memory

Cytokines are soluble regulatory proteins that act as intercellular ____ when released by certain body cells. Immune system cytokines are secreted by various ____cytes and affect diverse cells

messages leukocytes

MALT

mucosa-associated lymphoid tissue

Properties of Antigens: Properties that make certain molecules more effective at provoking adaptive immunity are a molecule's: ___, ___, and ___.

shape size complexity

Clonal Deletion of B Cells: -Occurs in the bone marrow in a manner similar/not similar? to deletion of T cells -End result is that self-reactive B cells are ____ from the active B cell repertoire

similar removed

Cell-Mediated Immune Responses: The body induces cell-mediated immune responses only against generic/specific? endogenous antigens

specific

Five attributes of adaptive immunity: Adaptive immune responses are precisely tailored reactions against specific attackers

specificity

Five attributes of adaptive immunity

specificity inducibility clonality unresponsiveness to self memory

____ filters blood and removes bacteria, viruses, toxins, and other foreign matter from the blood; stores iron

spleen

Antibody-Dependent Cellular Cytotoxicity: -Antibodies coat a target cell by binding to epitopes all over the target's ____. -The antibodies' stems can then bind to receptors on special lymphocytes called ____ cells (NK cells), which are neither B nor T cells. -NK cells destroy target cells with proteins called perforin and granzyme. Perforin molecules form into a tubular structure in the target cell's membrane, forming a channel thru which granzyme enters the target cells and lyse by triggering ____.

surface natural killer apoptosis

T cells are produced in the red bone marrow and mature under the influence of the _____

thymus

____ and ____: physically trap foreign particles and microbes.

tonsils and MALT

T/F APC's will present antigens from engulfed foreign bodies

true

T/F All the BCRs on a single B cell are the same, but the BCRs of one cell differ from the BCRs of all other B cells

true

T/F Larger molecules are better antigens than smaller ones

true

T/F The Fc regions of all antibodies of each class in a person's body are identical; that is, the Fc regions of all IgM molecules are identical, the Fc regions of all IgA molecules are identical, and so on for each antibody class.

true

T/F all human cells present cell-produced antigens

true

Th (1 or 2) - assist cytotoxic T cells and stimulate and regulate innate immunity

1

Th (1 or 2) - function in conjunction with B cells

2

_____ cells- dendritic cells, macrophages, and B cells which process antigens and activate cells of the immune system

Antigen presenting cells (APCs)

___ lymphocytes or __ cells are found in the spleen, MALT, and lymph nodes -Small percentage of circulate in the blood

B

Two basic types of white blood cells involved in adaptive immunity: ____ lymphocytes (_ cells) - arise and mature in the red bone marrow ____ lymphocytes (_ cells) - arise in the red bone marrow and mature in the thymus

B T

Surface of each B cell contains the ____ which is a type of immunoglobulin

B cell receptor (BCR)

Antibodies have identical antigen-binding sites and antigen specificity as the ___ of the activated B cell

BCR

MHC proteins in _____ function to ___ and ____ epitopes for presentation to immune cells

CM hold and position

Two categories of adaptive immune responses: ____ immune responses- carried out by T cells; often act against intracellular pathogens, such as viruses. ____ immune responses- carried out by B cells; act against extracellular pathogens and toxins.

Cell-mediated Humoral (antibody)

Types of Antibodies: Ig_ -secreted during the initial stages of immune response. -More than 5 times larger than the basic Y shape bc it is a pentamer, consisting of 5 basic units linked together -most efficient at complement activation, which also triggers inflammation -can be involved in agglutination and neutralization.

IgM

___ T lymphocyte - directly kills cells infected with viruses and other intracellular pathogens, as well as abnormal cells

Cytotoxic

Five classes of antibodies

IgM IgG IgA IgE IgD

A plasma cell attaches ___ coding for its heavy chain variable region to one of the 5 DNA sequences for the five types of stems to form one of five classes of antibodies known as IgM (immunoglobulin class mu), IgG, IgA, IgE, or IgD.

DNA

An antibody stem, which is formed of the lower portions of the two heavy chains, is also called the __ region (because it forms a fragment that is crystallizable). There are five basic types of stems (__ regions) designated by the letters (__5__)

Fc M G A E D

____ T lymphocyte - functions to help regulate the activities of B cells and cytotoxic T cells by providing necessary signals and growth factors (cytokines)

Helper

Class _ MHC Proteins are used to present antigens produced within the cell

I

Class __ MHC molecules are found on the cytoplasmic membranes of all cells except RBC (all nucleated cells)

I

Other infected cells in the body are also able to present antigens, these cells have only the Class _ MHC proteins

I

Processing endogenous antigens (come from a cell's cytoplasm or from pathogens living within the cell): A few molecules of each polypeptide (self and nonself) produced w/in nucleated cells are broken into small pieces and are loaded onto class __ MHC molecules This complex is then displayed on the cell's ___

I CM

Class _ MHC proteins are used to present antigens engulfed by antigen presenting cells (APCs)

II

Class __ MHC molecules are found on professional antigen-presenting cells (B cells, macrophages, and dendritic cells)

II

Types of Antibodies: Ig_ -most closely associated with body secretions -secretory Ig_- combination of Ig_ and secretory component, found in tears, mucous secretions, and breast milk, where it agglutinates and neutralizes antigens. -Of critical importance in protecting the body from infections rising in the gastrointestinal, respiratory, urinary, and reproductive tracts.

IgA

Types of Antibodies: Ig_ -not secreted, membrane bound antigen receptors on B-cells that are often seen during initial phases of an antibody immune response. -A BCR is composed of two transmembrane subunits bound to an immunoglobulin, which is either IgM or Ig_. -Uncertain of all the functions or importance.

IgD

Types of Antibodies: Ig_ -not critical for most antibody immune responses. -Act as signal molecules- attach to receptors on eosinophil CM's to trigger release of cell-damaging molecules onto the surface of parasites, particularly parasitic worms. -Also trigger mast cells and basophils to release inflammatory chemicals, such as histamine.

IgE

Types of Antibodies: Ig_ -most common and longest-lasting class of antibodies, accounting for ~80% of antibodies, possibly bc it has many functions. -Play a major role in complement activation, opsonization, neutralization, and antibody dependent toxicity. -Especially important during inflammation bc it enables binding to invading pathogens before they get into the circulatory systems. -also the only antibodies that cross a placenta to protect a developing child.

IgG

_____ house leukocytes that recognize and attack foreigners present in the lymph; filter the lymph

Lymph nodes

TCRs (T cell receptors) only bind epitopes associated with a _____

MHC protein

T cell maturation involves the production of ~500,000 copies of a ____ on each cell's cytoplasmic membrane

T cell receptor (TCR)

How are Class II MHC proteins loaded with antigens? a) Digested fragments are placed directly on the cell surface. b) Digested fragments are loaded onto MHC proteins in the endoplasmic reticulum. c) Digested fragments are combined with cell-produced antigens prior to MHC protein loading. d) Digested fragments in one vesicle fuse to another vesicle containing MHC proteins, then are brought to the surface.

d

How does the immune system recognize that a cell is infected with a virus? a) It detects viral antigens on the surface of antigen-presenting cells. b) It detects viral encoded proteins in the cytoplasm of the infected cell. c) It compares the antigens displayed on Class II MHC and looks for unrecognized viral antigens. d) It compares the antigens displayed on Class I MHC and looks for unrecognized viral antigens.

d

What types of cells do antigen-presenting cells seek out? a) viruses b) phagocytes c) virus-infected cells d) foreign cells in the body

d

What would a virus-infected liver cell in the body have on its surface? a) Class II MHC with viral antigens b) Class I MHC with macrophage antigens c) Class II MHC with liver cell antigens d) Class I MHC with viral antigens e) Class II MHC with bacterial antigens

d

If an antigen fragment cannot be bound to an MHC molecule, it typically does/does not? trigger an immune response

does not

Flow of lymph: The lymphatic system does/does not? have a unique pump and is/is not? circular. Lymph flows in ____ direction(s) towards the ____

does not is not one heart

Class I MHCs are found on which of the following cells? a) macrophages b) nerve cells c) dendritic cells d) #1 and #3 e) all of the above

e

Where does the loading of Class I MHC proteins occur? a) directly in the cytosol b) the cytoplasmic membrane c) the phagosome d) the nucleus e) the endoplasmic reticulum

e

Which cell can present antigens on Class II MHC proteins? a) virus-infected liver cells b) healthy liver cells c) monocytes d) macrophages e) monocytes and macrophages f) monocytes, macrophages, and virus-infected liver cells

e

Types of Antigens: Protozoa, fungi, bacteria, and viruses that reproduce inside the body's cells produce _____ antigens. The immune system cannot assess the health of the body's cells, it responds to these antigens only if the body's cells incorporate such antigens into their cytoplasmic membranes, leading to their external display.

endogenous

Antibody binding to ____ is the central functional feature of antibody immune responses

epitope

Properties of Antigens: Complex molecules make better antigens because they have more ______

epitopes

Agglutination: -Each antibody can attach to two ____ at once -Numerous antibodies can aggregate ____ together (agglutination) •Agglutination causes soluble molecules to precipitate -May hinder the activity of ____ -Increased/decreased? chance of phagocytosis -Increased/decreased? chance of being filtered by the spleen

epitopes antigens pathogens increased increased

Types of Antigens: ___ antigens come from outside the body's cells and include toxins and other secretions and components of microbial cell walls, membranes, flagella, pili.

exogenous

Structure of a B cell receptor (BCR): Made of 6 polypeptide chains- 2 identical longer chains called ___ chains 2 identical shorter chains called ___ chains, arranged in such a way that they form two arms that extend outside the cell and form the letter Y. 2 additional PP chains attach to the stem of the Y and anchor the BCR into the membrane, forming a ___ portion of the BCR

heavy light transmembrane

Processing exogenous antigens (extracellular sources): APC (usually dendritic cells) ____ the invading pathogen and breaks clips its proteins into segments. Epitopes are loaded onto class __ MHC molecules. This complex is then also displayed on the cell's ___.

phagocytizes II cytoplasmic membrane

Opsonization: -Antibodies act as opsonins- molecules that stimulate _____. -Opsonization - changing the surface of an ____ in order to enhance phagocytosis

phagocytosis antigen

Activated, immunoglobulin-secreting B cells are called _____

plasma cells

Before MHC proteins can display epitopes, antigens must be _______

processed

Properties of Antigens: Most effective are large foreign macromolecules such as ____ and ____ (carbohydrates and lipids can also be antigenic)

proteins and glycoproteins