Adaptive Immunity

Structure of antibodies

- contain two heavy chains and two light chains - have constant region and variable region

Clonal diversity: B cell maturation

-Directed by bone marrow sites that harbor stromal cells, which nurture the lymphocyte stem cells and provide hormonal signals -Millions of distinct B cells develop and "home" to specific sites in the lymph nodes, spleen, and GALT -Come into contact with antigens throughout life -Have immunoglobulin as surface receptors for antigens

Peripheral Tolerance of B cells

-functional, apoptosis-->deletion, regulation of inhibitory receptor

Molecules that recognize antigen

1. circulating antibody 2. antigen receptors on the surface of B lymphocytes (BCR) ( Be cell receptor complex) 3. antigen receptors on the surface of T lymphocytes(TCR)

What is the funciton of antibodies?

1. neutralize bacteria 2. neutralize viruses 3. bind with antigen to form antigen-antibody complexes

Antigen

A protein that, when introduced in the blood, triggers the production of an antibody

If a person has resistance to a disease from natural exposure (or vaccination) to an antigen, the person has which form of immunity? A. Natural B. Innate C. Passive acquired D. Active acquired

Active acquired Correct Active acquired immunity is obtained when an individual is exposed to the antigen.

What type of immunity is conferred when an individual is given a vaccine? a. natural immunity b. passive acquired immunity c. active acquired immunity d. alloimmunity

Active acquired immunity Correct A vaccine consists of a foreign antigen that induces a primary immune response. For this reason, vaccination confers active acquired immunity.

What type of immunity affords long-term protection against infectious disease?

Adaptive Immunity

Major histocompatibility class I (MHC I) antigens are found on which of the following cells? a. RBCs b. B lymphocytes and macrophages only c. all body cells except for RBCs d. Liver, heart, and bone marrow cells only

All body cells except for red blood cells Correct MHC I antigens are found on all cells except red blood cells.

Older individuals are at increased risk for which of the following problems? A. Autoimmune diseases B. Hypersensitivity reactions C. Infections D. All of the above

All of the above Correct Aging is associated with increased numbers of circulating autoantibodies that increase the occurrence of autoimmune diseases, increased numbers of circulating immune complexes that increase the occurrence of hypersensitivity reactions, and decreased numbers of circulating T cells and antibodies that increase the risk of infection.

An immune complex is formed by which of the following paired molecules? a. cytotoxic T cells and antigen b .antibodies and antigen c. B cells and antigen d. helper T cells and lymphocytes

Antibodies and antigen Correct An immune complex is also known as an antibody-antigen complex.

What does B-cell receptor complex consist of?

Antigen recognition and binding molecules (antibodies) and accessory molecules involved in intracellular signaling

What type of cells produce antibodies and confer humoral immunity?

B cell (B lymphocytes)

B cell antibody class switch

B cell activation there is an antigen recognized by b cell receptor. (BCR) Now there's going to be b cell receptor mediated endocytosis so that antigen will come inside the B cell. Now inside the B cell there is going to be complex formation between MHC2 and the foreign antigen. Once this complex has been formed, its going to get expressed on the B cell surface This MHC2 and the antigen complex is now going to get recognized by the tcell receptors on the T helper cell and this makes up the first signal now also on the picture here you could see that there is cd4 T recepors on the B cell which binds to the cd40 ligand which is on the T Helper cells and this is your signal 2. Now when both of these signals are achieved, the T helper cells will now release its cytokines and this will determine the IG class switching of the B cell so as you can see in the pic, all the interleukins are being released and its being recognized by the interleukin receptor which will cause B cell activation and make it undergo class switching and this finally causes The B cells to produce appropriate antibodies .

If a person is exposed to antigen x and is later exposed to antigen x again, which of the following immune responses will occur? a. primary b. secondary c. determinant d. immunosuppressive

B. Secondary Correct This person mounted a primary immune response after his/her first exposure to antigen X and a secondary immune response after the second exposure.

How is the immune system affected by age? a. the immune system remains the same with age b. The immune system becomes stronger d/t previous exposure to antigens c. immune system becomes weaker with age d. immune system does not need support as age advances

B. The immune system becomes weaker with age The immune system becomes weaker with age, d/t a decrease in tcell activity

Cytotoxic T Cells can cause apoptosis of infected or cancer cells by which of the following mechanisms? a. producing toxins (perforin) b. expressing Fas ligand c. producing antibodies d. both a and b

Both a and b Correct Tc cells can destroy microorganisms or cancer cells by releasing toxins such as perforin and inducing apoptosis of the malignant or infected cell.

Which molecule is found on the surface of antigen-presenting cells (APCs) that present lipid antigens and plays an important role in recognizing tuberculosis infections? a. CD1 antigen b. Rh antigen c. BCR antigen d. MHC II antigen

CD1 antigen Correct CD1 antigens are found on the surface of APCs that can present lipid antigens. This is important for the recognition of Mycobacterium tuberculosis, the bacterium that causes tuberculosis.

T cells

Cells created in the thymus that produce substances that attack infected cells in the body.

MHC describe class I and class II

Class I - self recognition for all nucleated cells Class II - primarily on APC's (macrophage, B cells) + others

The selection and proliferation of mature and B and T cells in response to exposure to a specific antigen

Clonal selection

agglutination

Clumping of microorganisms or blood cells, typically due to an antigen-antibody interaction.

MHC: Coded by?

Coded by MHC genes from different loc on chromosome 6

What is CD1 coded by?

Coded by genes on chromosome 1

Tc do what?

Cytotoxic t cells - mediated killing

What are the most common antigen process and presenting cells (APC's)

Dendritic cells macrophages B lymphocytes

Which of the following is not a function of antibodies? A. Neutralizing bacterial toxins B. Preventing viruses from entering tissue cells C. Direct cell killing through the release of toxic chemicals D. Opsonizing foreign antigen

Direct cell killing through the release of toxic chemicals Correct Antibodies are inflammatory proteins and do not have the capacity to secrete toxic chemicals.

What are teh two main effector functions of activated T cells?

Direct killing (Cytotoxic T cells -Tc) T regulatory cells (T reg)

Passive immunity

Does not involve the host's immunse system Ie andiministration of preformed antibodies or T lymphocytes can be Passive - from mom active - from serum

Clonal diversity: T cell maturation process

Double negative (subcapsular zone) --> cortex --> double positive --> if insufficient affinity for self MHC then apoptosis = positive selection by cortical epithelial cells --> single positive in medulla --> if they have excessive affinity for self antigens for MHC then apoptosis = negative selection

Why are helper T cells necessary?

For the process and critical to an effective immune response

Antigens (nonself)

Foreign material that invades the body and can excite the immune system and provoke an immune response (Non self) Examples: foreign proteins nucleic acids Large carbohydrates some lipids pollen grains microorganisms

What are the two phases of adaptive immunity?

Generation of clonal diversity and clonal selection

Which cell stimulates both the cell-mediated and humoral immune responses? a. plasma cell b. cytotoxic c. B lymphocyte d. Helper T cell

Helper T cell Correct Helper T cells stimulate the proliferation and differentiation of B and T cells, thus exerting control over both the cell-mediated and humoral immune responses.

B Cell activation causes what response?

Humoral immune response

Which is the main antibody transferred from a mother to an infant in breast milk? A. IgG B. IgM C. IgE D. IgA

IgA Correct IgA, also known as secretory IgA, is found in the secretions from any mucosal surface, including the mammary glands. It is the primary antibody found in breast milk and confers passive acquired immunity to the breast-feeding infant.

When a person has an allergic reaction to bee stings, which antibody causes the life-threatening hypersensitivity response? a. IgM b. IgA c. IgE d. IgG

IgE Correct IgE is the predominant antibody in an allergic response.

Select the statement which is true concerning immunoglobulin levels: a. in utero, a fetus can produce IgA and igG b. After birth, IgM is passed through breast feeding c. IgG is present in the infant at birth, but declines quickly d. There are no immunoglobulins available for immunity in the newborn

IgG is present in the infant at birth, but declines quickly. Correct In the uterus, the fetus is able to produce some IgM; however, it cannot produce IgG and IgA and is dependent on the active trophoblastic transport of maternal IgG into the fetal circulation. After birth, the amount of maternal IgG declines before the infant can begin making adequate amounts of its own IgG, so a transient hypogammaglobulinemia occurs, during which the infant is susceptible to a number of infections.

The predominant antibody of typical secondary immune response is: a. IgG b. IgM c. IgE d. IgA

IgG. Correct IgG is the predominant antibody in a secondary immune response constituting 80-85% of circulating antibodies.

Antibody classes

IgM, IgA, IgD, IgG, IgE

Cellular immunity -

Immune responses mediated by activated, antigen-specific T lymphocytes. These T cells may function as effector cells or may orchestrate propagation of the inflammatory response and cellular recruitment through their secretion of cytokines and chemokines.

What are memory cells?

In biology, a memory cell refers to one of a number of types of cells that make up part of the immune system. These cells are a vital part of the system that defends the body against pathogens such as bacteria or viruses that cause disease and infection. They are one type of white blood cell or lymphocyte. There are two main types, called memory T cells and memory B cells. T cells activate the immune system and directly attack pathogens, while B cells produce substances called antibodies, which can disable or kill pathogens.

Induction of an in immune response: clonal selection Successful invasion by a pathogen elicits ________ immunity -- the __________ response. Some of these cells communicate with immature _________ & ______________- cells to initiate specific immunity B cells encounter antigen in the secondary lympohid tissues; ________, ___________ _________, ____________ __________ and the ____________________

Innate Inflammatory B and T spleen, lymph nodes, Peyer's patches and the appendix.

Which cytokine is produced by macrophages to stimulate the immune response? A. Colony-stimulating factor B. Tumor necrosis factor C. Interleukin 1 D. Interleukin 2

Interleukin 1 Correct Interleukin 1 is produced by macrophages to stimulate the immune response.

Antibodies provide a secretory immune response. Describe

It is a line of defense provided by antibodies (primarily IgA with some IgG and IgM ) produced in secretions (tears, sweat, saliva, breast milk and in the mucous membranes)

Immunoglubulin vs antibody

Key Difference - Immunoglobulin vs. Antibody The production of antibodies is the key function of the human immune system. The antibody can identify and neutralize pathogens such as bacteria and viruses. Both immunoglobulin and antibody are substitutable terms. Some scientists believe that immunoglobulin as the main class of proteins that antibodies belong to based on their overall protein structure. This is the key difference between immunoglobulin and antibody. .

self antigen and tolerance Size and complexity

Larger antigens have stronger immunogenicity nonimmunologic usually laess than 1000 daltons immunogenic more than 6000 daltons larger, more complex antigens are usually better recognized and more susceptible to phagocytosis exceptions: glucogon (~3400 daltons) can be immunogenic and large homopolyers are not immunogenic

Which of the following statements best describes the process of clonal selection? A. An antigen directly activates B- and T-cell clones. B. Lymphocytes that can recognize and react to a specific antigen proliferate. C. A single lymphocyte develops the ability to recognize multiple antigens. D. A B lymphocyte is selected to become a T cytotoxic cell.

Lymphocytes that can recognize and react to a specific antigen proliferate. Correct The process of clonal selection occurs when an antigen selects those lymphocytes with compatible receptors and expands their population. The immunocompetent B and T lymphocytes also differentiate into mature B and T cells

How does T lymphocyte tolerance to self-antigen develop? A. Stem cells are signaled not to produce lymphocytes that can recognize self-antigen. B. Lymphocytes that have the ability to recognize self-antigen undergo apoptosis. C. Lymphocytes are stimulated to mutate into a cell that recognizes a foreign antigen. D. T-lymphocyte tolerance to self-antigen develops through clonal deletion in the spleen.

Lymphocytes that have the ability to recognize self-antigen undergo apoptosis. Correct During the generation of clonal diversity, T lymphocytes that can react with self-antigen are stimulated to undergo apoptosis.

Cell surface proteins distinguising self from non-self but are also involved in antigen presentation

MHC - Major Histocompatibility Complex

Which cell ingests microorganisms for the purposes of presenting their antigen to the immune system and activating an immune response? A. Helper T cell B. Mast cell C. Neutrophil D. Macrophage

Macrophage Correct Macrophages are phagocytes that are involved in antigen processing and presentation for the purpose of activating an immune response

__________________ are very effective in presenting antigen to T helper cells.

Macrophages

Which of the following is an example of an endogenous antigen? a. poison ivy b injected medications c. pollen d. malignant cells

Malignant cells Correct The body's own tissues are considered endogenous antigens because they originate from within the body. Intracellular infections and malignancies are examples.

For tissue, organ/bone marrow transplantation what does MHC have to do with this? Who is the best chance of a match?

Match MHC molecules (human leukocyte antigens - HLA) Best chance of match is with a sibling

T cell activation produces what cells?

Memory T

Which type of antibody can be created in a laboratory for the treatment of diseases such as cancer and will only react with a single antigen? A. Polymorphic B. Monoclonal C. Totipotent D. Deterministic

Monoclonal Correct Monoclonal antibodies are created by proliferation of a B-cell clone, the antibodies of which will only react with a single type of antigen.

IgE antibodies

Monomer 0.002% of serum antibodies On mast cells, on basophils, and in blood Allergic reactions; lysis of parasitic worms Half-life = 2 days

IgD antibodies

Monomer 0.2% of serum antibodies In blood, in lymph, and on B cells On B cells, initiate immune response Half-life = 3 days

IgG antibodies

Monomer 80% of serum antibodies Fix complement In blood, lymph, and intestine Cross placenta Enhance phagocytosis; neutralize toxins and viruses; protects fetus and newborn Half-life = 23 days

effector cells

Muscle cells or gland cells that carry out the body's response to stimuli.

How do natural killer (NK) cells differ from cytotoxic T cells (Tc)? A. NK cells lack antigen-specificity and can target any infected or malignant cell. B. NK cells are phagocytic. C. NK cells can opsonize bacteria and viruses. D. NK cells release toxins that kill the target cell.

NK cells lack antigen-specificity and can target any infected or malignant cell. Correct Tc cells recognize specific antigen, whereas NK cells can recognize any infected or malignant cell.

Active Immunity

Occurs after either exposure to an antigen or with immunization can be naturally acquired - like getting mumps or artificially acquired - getting MMR

Where are CD1 found mostly?

On APCs and cells of the thymus

IgM antibodies

Pentamer 5-10% of serum Abs Fix complement In blood, in lymph, and on B cells Agglutinates microbes; first Ab produced in response to infection Half-life = 5 days

IgA

Plays crucial role in mucosal membrane immunity The amt of IgA produced in association with mucosal membranes is greater than all the other types of antidoy combined

Natural immunity

Present at birth species specific a usually inherent, nonspecific form of immunity to a specific disease. Kinds of natural immunity include individual immunity, racial immunity, and species immunity

What does CD1 specialize in ?

Presenting lipid antigens

B cell activation: the humoral response is involved in what types of immune response?

Primary and secondary immune With first exposure to antigen IgM and then IgG; Subsequent exposure to same antigen titer goes up.

clonal diversity

Production of T and B lymphocytes Antigen recognition Lymphocyte specificity

Which process confers long-lasting immunity against a specific antigen? A. Production of memory cells B. Activation of macrophages C. Activation of cytotoxic T cells D. Activation of the inflammatory response

Production of memory cells Correct Production of memory cells allows the body to have immunity against an antigen, even years after the initial exposure.

What role does opsonization play in the immune and inflammatory response? a. prevents the lymphocytes from attacking self-antigen b. stimulates cytotoxic T cells c. stimulates exudation of WBC into the tissues d. promotes phagocytosis of foreign antigen

Promotes phagocytosis of foreign antigen Correct Opsonization is the process by which an antigen is made recognizable as a foreign substance. The opsonized antigen attracts phagocytes that in turn will destroy the foreign antigen.

Adaptive immunity: Lymphocytes are released from these organs into circulation where they migrate to ___________ _________ _________ and take up residence (give examples of where they migrate to)

Secondary lymphoid tissues spleen and lymph nodes

Which pair of relatives has the highest chance of sharing both HLA haplotypes, making them a good match for an organ transplant from one to the other? a. mom and daughter b. father and son c. siblings d. mother and father

Siblings Correct Since each sibling receives one haplotype from each parent, they have the highest chance of sharing both.

What happens when Thp cell secretes IL-2?

Stimulates the proliferation of Thp cells signals Thp cells to differentiate into Th1, Th2, or new Th17 cells Formation of Th1, Th2 and Th17 cells

Il-2

T cell growth factor

T cells (T lymphocytes) differentaite into ______________ cells (+ others) and confer ___________ __________ immunity

T cytotoxic cell mediated

Heper T cells: _________ and _____________ molecule on Th precursor cell (Thp_ binds to MHC class II receptor on ____________-

TCR and CD4 APC

What is the role of a B receptor complex (BCR)

TO recognize antigen and communicate that info to the cell's nucleus

Fab antibody fragments

The antigen-binding (Fab) fragment is a region on an antibody that binds to antigens. It is composed of one constant and one variable domain of each of the heavy and the light chain

Fc: crystalline fragment

The fragment crystallizable region (Fc region) is the tail region of an antibody that interacts with cell surface receptors called Fc receptors and some proteins of the complement system. This property allows antibodies to activate the immune system.

Histocompatibility

The immunologic similarity between an organ donor and a transplant recipient

What is the key difference between humoral and cell mediated immunity?

The key difference between humoral and cell mediated immunity is that the humoral immunity (antibody-mediated immunity) involves antibodies while the cell mediated immunity does not involve antibodies.

clonal selection

The process by which an antigen selectively binds to and activates only those lymphocytes bearing receptors specific for the antigen. The selected lymphocytes proliferate and differentiate into a clone of effector cells and a clone of memory cells specific for the stimulating antigen.

What is the most important step in clonal selection?

The production o f two types of Th cells Th1 and Th2

Antigen vs Immunogen

The terms antigen and immunogen are often used interchangeably, and for most purposes, the difference is irrelevant. But to be precise, they describe two types of interactions between a molecule and the immune system. An immunogen refers to a molecule that is capable of eliciting an immune response by an organism's immune system, whereas an antigen refers to a molecule that is capable of binding to the product of that immune response. So, an immunogen is necessarily an antigen, but an antigen may not necessarily be an immunogen.

Lymphocytes

The two types of white blood cells that are part of the body's immune system: B lymphocytes form in the bone marrow and release antibodies that fight bacterial infections; T lymphocytes form in the thymus and other lymphatic tissue and attack cancer cells, viruses, and foreign substances.

What is the function of regulatory T cells (Treg) a. Prevent lymphpcytes from attacking self-antigen b. Suppress inflammatory response c. enhance the activity of antigen presenting cells d. they are involved in the development of passive immunity

They enhance the activity of antigen-presenting cells. Correct T reg cells suppress the immune response and play an important role in the immune system's tolerance to its own antigen.

_________________- cell secretes Il2

Thp

B cell activation: The humoral response differentiated B cell becomes a _______________ cell after ________ encounter.

a plasma cell antigen

Antigenic determinant

a site on the surface of an antigen molecule to which a single antibody molecule binds; generally an antigen has several or many different antigenic determinants and reacts with many different antibodies

Th1 activates what?

activate cells related to cell-mediated immunity (macrophages)

Th2 activates what?

activate eosinophils and B cells to produce IgE

Adaptive Immunity: The entire population of immunocompetent B and T cells has the ability to recognize ______ _______ _________. However, each group of individual B or T cells has ____________ ___________ for one antigen.

all foreign antigens receptor specificity

proliferation

an increase in number, multiplication

B cell activation: Plasma cells produce what?

antibodies

Immunoglobulins

antibodies

antibodies bind with antigens to form ________ - _________________ complexes

antibody - antigen complexes

Clonal selection: B cells differentiate in to what type of cells? T cells differentiate into what type of cells

antibody-producing plasma cells cytotoxic T Cells

Clonal selection involves ________ processing and presentation by __________ __________ cells. to the immature lymphocytes.

antigen antigen processing

Molecules that present antigen

antigen presenting cells (APC's) Major Histocompatibility Complex (MHC)

Immune system is continually challengd by foreign substances called __________

antigens

Haptens

antigens too small to provoke immune responses; attach to carrier molecules (incomplete antigens)

Molecules that are capable of inducing an immune response are called: a. lymphocytes b. haptens c. antigens d. antibodies

antigens. Correct Antigen is the term used to describe a molecule that has the capacity to induce an immune response by the lymphocytes

Self antigen

any molecule or chemical group of an organism which acts as an antigen in inducing antibody formation in another organism but to which the healthy immune system of the parent organism is tolerant.

T-cell immunity is altered at puberty secondary to: A. decreases in bone marrow production of T cells. B. atrophy of the thymus. C. the diminishing effects of most childhood vaccines. D. the inhibitory effects of sex hormones on T-cell function

atrophy of the thymus. Correct Atrophy of the thymus at the time of puberty results in a decrease in cell-mediated immunity because the thymus is the site of T-cell maturation.

The condition in which the immune cells attack the individual's own tissues as if they were invaders is called: A. alloimmunity. B. autoimmunity. C. hypersensitivity. D. graft rejection.

autoimmunity. Correct Autoimmune diseases occur when the lymphocytes mount an immune response against the body's own tissues.

How does an individual obtain passive immunity? a. obtaining an immunization b. after natural exposure to an antigen c. by washing hands before eating d. during immunotherapy

b. after a natural exposure to an antigen A natural exposure to an antigen is called passive immunity

Mast cells facilitate the inflammatory response by all of the following methods except: a. constriction and dilation of capillaries b. bradykinin production c. chemotaxis and neutrophils d. stimulation of cell growth and angiogenesis

b. bradykinin production although important in facilitating inflammation, bradykinin is not produced by mast cells but is produced by the kinin protein system

When antibodies neutralize viruses it prevents what? agllutination and ____________________

binding and entrance to host cells precipitation

When antibodies neutralize bacteria It prevents what? Causes __________ & precipitation Prevents secretion of _____________ toxins

binding of bacteria to tissue cells agglutination bacterial toxins

The portion of the antigenic molecule that is recognized by the lymphocyte is called the antigenic determinant or: A) MHC complex. B) immunoglobulin. C) epitope. D) haplotype.

c. epitope The epitope is another name for the antigenic determinant

Which of the following is accurate regarding the function of leukocytes in providing defense against microorganisms? a. macrophages recognize and eliminate viruses and cancer cells b. natural killer cells serve as a primary defense against parasites c. neutrophils recognize and eliminate bacteria d. eosinophils remove dead cells and cellular debris

c. neutrophils recognize and eliminate bacteria.

Different APC cells influence whether Th1, Th2, Th17 is produced Th1 plays a role in stimulating what? Th2 plays a role in stimulating what? Th17 increases what response

cell- mediated immunity humoral (anitbody formation) immunity inflammatory response

central tolerance

cells that bind to "self" cells are eliminated in bone marrow

What produces memory cells?

cellular immunity

memory t cells function

circulate the body, proliferate, and respond to eliminate subsequent invasion by same antigen. (2ndary response - takes less time, ~5 days)

memory b cells function

circulate the body, proliferate, and response quickly (via antibody synthesis) to eliminate subsequent invasion by same antigen. (2ndary response - takes less time, ~5 days)

Regulatory T cells

control the T-cell response

Th1 cells stimulate the proliferation and differentiation of: A. cytotoxic T cells. B. B cells. C. eosinophils. D. regulatory T cells.

cytotoxic T cells. Correct Th1 cells stimulate the proliferation and differentiation of cytotoxic T cells (Tc) and macrophages

All of the following are important/principal chemical mediators of inflammation except: a. cytokines such as interleukins, interferon, and tumor necrosis factor b. chemokines such as monocyte/macrophage chemotactic proteins c. histamine released when mast cells degranulate d. angiogenesis factors, such as vascular endothelial growth factor

d. angiogenesis factors, such as vascular endothelial growth factor. angiogenesis factors, such as vascular endothelial growth factor, are important during the reconstructive phase of tissue healing and are not proinflammatory

All of the following include basic characteristics of the vascular acute inflammatory response except: a. local vasodilation b. increased vascular permeability c. WBC adherence and migration d. fibroblast attraction to site

d. fibroblast attraction to site Fibroblast attraction to site occurs later during the healing phase of injury

Which of the following constitute the third line of human defense mechanisms? a. mast cells and macrophages b. complement and kinins c. activated lympocytes and antibodies d. lympohyctes and antibodies

d. lymphocytes and antibodies Lymphocytes and antibodies constitue the third line of defense in protection from infection

Blocking the Th2 cell response would: A. block the entire immune response. B. decrease macrophages. C. decrease antibody production. D. decrease Tc cell response.

decrease antibody production. Correct Blocking the Th2 cell response would only decrease the differentiation of B cells to plasma cells and therefore would result in decreased antibody production.

effector mechanism

effectors directly influence controlled physiological variables antibodies Ab then provide a secretory immune response

The portion of the antigenic molecule that is recognized by the lymphocyte is called the antigenic determinant or: A. MHC complex. B. immunoglobulin. C. epitope. D. haplotype.

epitope. Correct The epitope is another name for the antigenic determinant.

Clonal selection: These antigen-selected cells mount a defensive response against the ___________ antigen.

foreign

CD4 receptors that bind to the surface of macrophages and B cells are found on: A. helper T cells. B. cytotoxic T cells. C. plasma cells. D. the human immunodeficiency virus (HIV).

helper T cells. Correct CD4 receptors are found on helper T cells.

B cells (B lymphocytes) produce antibodies and confer _____________ immunity

humoral

humoral immunity

immunity associated with antibodies

Why are CD1 improtant?

important for some bacterial infections in which the bacteria have large mounts of lipids in their cell membranes.

The Fc portion of the antibody: a. is responsible for binding to specific antigen b. is responsible for creating the hinge region of the antibody c. consists of light chains d. interacts with inflammatory cells

interacts with inflammatory cells. Correct The Fc portion of the antibody interacts with inflammatory cells and proteins.

The primary cell of immunity is the: A. mast cell. B. macrophage. C. neutrophil. D. lymphocyte.

lymphocyte. Correct Lymphocytes (B and T cells) are responsible for generating immune responses

products of adaptive immunity

lymphocytes (B and T cells) immunoglobulins (antibodies)

Which of the following constitute the third line of human defense mechanisms? a. mast cells and macrophages b. complement and kinins c. activated lymphocytes and antibodies d. lymphocytes and antibodies

lymphocytes and antibodies Correct Lymphocytes and antibodies constitute the third line of defense in protection from infection.

Recognition and response: a successful immune resonse depends on recogition of the foreign antigen by _______________ and/ or _______________ Recognition molecules on the surface of lympohcytes and APC's are known as the_________________________________________________________________ proteins A large number of ______________ also contribute to the acquired immune response

lympohcytes APCs (antigen presenting cells) Cluster of differentiation proteins (CD) cytokines (cell chemical communcators)

T cells can activate __________________

macrophages

Immune cells distinguish "self" from "non-self" by recognizing a. cellular RNA b. major histocompatibility antigens c. different types of phospholipids in a cell's membrane d. "non-self" enzymes secreted by foreign cells.

major histocompatibility antigens. Correct Immune cells distinguish "self" from "non-self" by recognizing major histocompatibility antigens on a cell's plasma membrane.

Immunocompetent B and T cells with receptor specificity are selected and stimulated to ___________ and ____________-

mature and proliferate

B cells activation produces ___________ _________ cells

memory B

NK

natural killer cells

Where are B cell receptors complex (BCR) found?

on the surface of immunocompetent B cells

Clonal selection: Moste immune responses are ________________.

polyclonal

Secretion of I1-1 by APC signals what?

precursor helper T cells (Thp)

Humoral immunity is generated through the process of: A. direct cell lysis. B. stimulating an inflammatory response. C. producing antibodies. D. secreting toxic molecules.

producing antibodies. Correct Humoral immunity involves the production of antibodies that attack foreign antigens.

T cell receptor complex - T cells use a similar, but distinct array of ___________for recognition and binding to antigens

proteins

Immunoglobulins (antibodies)

proteins produced by B-cells neutralize targets (toxins, bacteria) in the body recruit other cells to help eliminate the threat

Processing and presentation of antigen is necessary as most antigens do not what?

react directly with immature T or B cells

In contrast with the inflammatory response, the immune response: A) is more effective at fighting microorganisms. B) is faster. C) recognizes specific invaders. D) has no memory.

recognizes specific invaders. Correct Immune cells have the capacity to recognize a specific antigen, whereas inflammatory cells respond in the same manner to any foreign antigen.

self antigen and tolerance: foreignness

refers to the phytogenic relationship between the host and the antigen, generally the further apart, the better the response

T regulatory cells (Treg)

regulate the immune response to avoid attacking "self" - avoid over-activation of immune system - avoid attacking self antigens

Antibody-dependent cellular cytotoxicity

targets cell for destruction by natural killer (NK) cells

The generation of clonal diversity is: A. the reaction of a lymphocyte to a specific antigen. B. the development of natural immunity. C. the ability of the population of lymphocytes to recognize any antigenic molecule. D. the circulation of lymphocytes through the spleen.

the ability of the population of lymphocytes to recognize any antigenic molecule. Correct Through clonal diversity, lymphocytes have the capacity to recognize an estimated 1018 different antigens that might be encountered in the life of an individual.

adaptive immunity

the ability to recognize and remember specific antigens and mount an attack on them

T cell activation

the stimulation of mature naive T cells by antigen presented to them by professional antigen-presenting cells. It leads to their proliferation and differentiation into effector T cells.

T cell receptor (TCR) comples is a _____________________ protein and a group of accessory proteins that are involved in ______________________- ____________________-

transmembrane intracellular signaling

Which of the following cells has the capacity to produce antibodies during and immune response? a. plasma cells b. t cells c. memory cells d. pluripotent cells

which of the following cells has the capacity to produce antibodies during an immune response? A. Plasma cells Correct Plasma cells are B lymphocytes that have developed the ability to produce antibodies during an immune response.