Lecture Exam 3 CH 16 - LC

What are the 5 classes of antibodies? Which class of antibody is the first one produced upon infection? Which class establishes a long-lasting immune effect?

IgM, IgA, IgD, IgD, Ige IgM is the 1st antibody produced IgG is the longest lasting antibody/immunity

What are Autoantigens?

antigens on the surface of NORMAL body cells - represent "self" cells

True/False, if false correct Adaptive immune responses initiate at the site of an infection.

False Adaptive immune responses INITIATE in LYMPHOID ORGANS, usually lymph nodes, where antigen-presenting cells interact with lymphocytes.

True/False, if false correct Lymphocytes with CD8 glycoprotein are HELPER T-cells.

False Lymphocytes with CD8 glycoprotein are Cytotoxic T-cells.

True/False, if false correct MHC Class II molecules are found on T-CELLS.

False MHC Class II molecules are found on ANTIGEN-PRESENTING CELLS.

True/False: If false, correct. B-Cells and T-cells are formed and mature in the red bone marrow.

False T-cells mature in the thymus

True/False, if false correct A TCR is a surface molecule composed of one polypeptide containing a single epitope-binding site.

False - TCR is a surface molecule composed of TWO polypeptides containing a single epitope-binding site BETWEEN them

True/False, if false correct. TCR's directly recognize epitopes.

False they do NOT recognize epitopes directly

True/False, if false correct Secretion of antibodies by activated B cells is a form of CELL-MEDIATED immunity.

False. Secretion of antibodies by activated B cells is a form of ANTIBODY MEDIATED immunity.

True/False - if false, correct: Similar to MHC, each TCR binds to many unique epitomes

False: Each TCR binds to ONE specific epitope binding site

True/False: if false, correct. Adaptive Immunity is all organisms ability to recognize and mount defense against distinct invaders and their products.

False: it applies ONLY to vertebrae/humans

What are Major Histocompatibility Complex (MHC)?

Group of genes that code for proteins found on the surfaces of cells that help the immune system recognize foreign substances. Important in determining tissue compatability

What is cell-mediated immune response

The branch of acquired immunity that involves the activation of cytotoxic T cells, which defend against infected cells.

A physician wants to stimulate immunological memory in a patient. Which of the following types of immunity would be the most useful? a) give the patient immunoglobulins b) give the patient breastmilk c) have the patient shake hands with an infectious individual d) vaccinate with viral proteins

d) vaccinate with viral proteins

Explain "clonal deletion"

lymphocytes are exposed to autoantigens, those that react undergo APOPTOSIS - programmed cell death

List the ELEMENTS of adaptive immunity (what the lymphatic system contains)

1) lymphatic vessels 2) lymphoid cells 3) tissues 4) organs

What are the two pathways that a Tc cell kills a virus?

1) perforin-granzyme pathway - causes apopsosis 2) CD95 pathway

List the 5 attributes of adaptive immunity

1) specificity 2) inductability 3) clonality 4) unresponsiveness to self 5) memory

What is the role of lymphatic vessels?

1-way transport of lymph towards the heart

Place the following steps of phagocytosis in the order that they occur: 1) Endosome fuses with lysozome 2) Dendritic cell engulfs Rhinovirus 3) Epitopes are attached to MHC-II 4) Digestion of the Rhinovirus 5) MHC-II plus the attached epitope move to the outside of the dendritic cell

2,1,4,3,5

Correctly order the steps involved cellular immunity: 1) The Tc recognizes the infected host cell 2) The Tc interacts with epitope presented by MHC-I on the dendritic cell 3) The Tc secretes perforin and granzyme, causing apoptosis 4) The helper T cell activates the Tc cell

2,4,1,3

True/False, if false correct APOPTOSIS is the term used to describe cellular suicide.

True

True/False, if false correct Each T-cell expresses only one TCR and displays only one specific Epitope binding site.

True

True/False, if false correct. T-cells do not recognize antigens directly; they must be presented on MHC.

True

True/False, if false correct CYTOTOXIC T-CELLS secrete immunoglobulin.

False PLASMA CELLS secrete immunoglobulin.

What is an antibody

A protein that binds to and acts against a specific antigen

Which of the following (select all that apply) do cell-mediated immune system respond to: a) viruses b) cancer cells c) intracellular protozoa d) intracellular bacteria

ALL of the above

Which type of immune responses do B and T cells exhibit (cell mediated or antibody)

B-cells are antibody immune response T-cells are cell-mediated immune responses

An Autoantigen is A.) an antigen from normal microbiota B.) a normal body component C.) an artificial antigen D.) any carbohydrate antigen E.) a nucleic acid

B.) a normal body component

Which of the following is NOT a step used by cytotoxic T cells to kill infected host cells? A)Secretion of granzyme B) Recognition of infected host cell using its TCR C) Recognition of infected host cell using its CD4 glycoprotein D) Secretion of perforin

C) Recognition of infected host cell using its CD4 glycoprotein

Which class of antibodies is mainly found in sweat, tears, breast milk and GI secretions?

IgA

Which class of antibodies is the most versatile (meaning it can have the greatest variety of effects and is longest lasting?

IgG

What is antibody-mediated (HUMORAL) immunity

The production of antibodies by B cells in response to an antigen. Also called humoral immunity.

True/False, if false correct: The body induces cell-mediated immune responses only against specific endogenous antigens.

True

Which type of Helper T-cell functions in conjunction with B-cells?

Type 2 Helper T-cells (Th2)

Which pair of molecules do NOT directly interact with one another? a) BCR and TCR b) BCR and epitope c) CD4 and MHC-II d) CD8 and MHC-I

a) BCR and TCR

What is a characteristic of a chemical that makes it a good antigen for the immune system? a) Complex molecules are usually good antigens. b) Autoantigens are usually good antigens. c) Small size is a characteristic of a good antigen. d) An antigen with very few epitopes is a good antigen.

a) Complex molecules are usually good antigens. Complexity is a characteristic of a good antigen because complex molecules have multiple possible epitopes.

Which type of T cell positively affects both B cells and T cells? a) Helper T cells b) Suppressor T cells c) Cytotoxic T cells d) Regulatory T cells

a) Helper T cells Helper T cells produce signals and growth factors that help regulate the activity of B cells and cytotoxic T cells.

Tc cells recognize epitopes only when the latter are held by _____. a) MHC proteins b) B cells c) interleukin 2 d) granzyme

a) MHC proteins

If someone gets measles, and is immune to measles as a result, what type of immunity is this? a) Naturally acquired active immunity b) Artificially acquired active immunity c) Artificially acquired passive immunity d) Naturally acquired passive immunity

a) Naturally acquired active immunity Getting the disease is a natural method of antigen exposure, and the immunity is active because the immunity is from the body's own response.

Match each cell with the assoc protein choosing from: MHC II Molecule, Interleukin 4, Perforin and granzyme, or Immnunoglobulin a) Plasma Cell b) Cytotoxic cell c) Th2 cell d) Dendritic cell

a) Plasma Cell -- Immunoglobulin b) Cytotoxic cell -- Perforin and granzyme c) Th2 cell -- Interleukin 4 d) Dendritic cell -- MHC II molecule

Which of the following lymphocytes predominates in blood? a) T cells b) B cells c) plasma cells d) memory cells e) all are about equally prevanent

a) T cells

Which part(s) of B cell receptors form the antigen-binding sites? a) The variable regions of the heavy and light chains b) Only variable regions of the heavy chains c) The disulfide bonds of a B cell receptor d) The transmembrane portion of a B cell receptor

a) The variable regions of the heavy and light chains

What are exogenous antigens?

antigens from OUTSIDE the cell that have been engulfed by the cell that displays them includes toxins, secretions, and components of microbial cell walls, membrane, flagella, and pili

What are endogenous antigens?

antigens produced by microbes that multiply INSIDE the cells of the body

Which of the following is NOT a step that ultimately leads to antibody production? a) Activation of helper T cells by dendritic cells b) Activation of cytotoxic T cells by helper T cells c) Differentiation of plasma cells d) Immature B cells conducting surveillance for foreign epitopes

b) Activation of cytotoxic T cells by helper T cells

Which type of cytokine signals white blood cells to move toward a site of infection? a) ILs b) Chemokines c) TNF d) IFNs

b) Chemokines

What is the role of helper T cells in the adaptive immune response? a) Helper T cells phagocytize bacteria and viruses. b) Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells. c) Helper T cells produce and secrete antibodies. d) Helper T cells directly kill infected host cells.

b) Helper T cells activate B cells and cytotoxic T lymphocytes to kill infected host cells.

How are the lymphatic system and cardiovascular system similar or dissimilar? a) Blood capillaries are much more permeable than lymphatic capillaries. b) Lymph is similar in composition to blood plasma. c) Both blood vessels and lymphatic vessels have a pump to circulate fluids. d) Both blood vessels and lymphatic vessels are circulatory systems.

b) Lymph is similar in composition to blood plasma.

The characteristic of adaptive immunity by which the adaptive immune response acts against one molecular shape and no others is called __________. a) clonality b) inducibility c) memory d) specificity

d) specificity Specificity provides the specific immune response with a precisely tailored reaction against specific attackers.

Adaptive immunity has characteristics that distinguish it from innate immunity, one of which is inducibility. What is inducibility? a) When adaptive immunity responds only to a specific pathogen b) When pathogens activate adaptive immunity c) When there is a virus that can infect both animals and humans d) When a virus cannot cause disease in a particular human because that individual lacks the specific receptor that the virus glycoprotein binds to

b) When pathogens activate adaptive immunity The adaptive immune system is activated or induced in response to pathogens.

The ability of a specific immune cell to proliferate and form many generations of nearly identical cells is called __________. a) specificity b) clonality c) memory d) inducibility

b) clonality Specific immune cells such as B cells make a huge impact on the immune response, in part because of their ability to rapidly clone themselves, a characteristic called clonality.

Antibodies function to _________. a) directly destroy foreign organ grafts b) mark invading organisms for destruction c) kill intracellular viruses d) directly promote cytokine synthesis e) stimulate T cell growth

b) mark invading organisms for destruction

Breastfeeding is an example of which of the following types of immunity? a) naturally acquired active immunity b) naturally acquired passive immunity c) artificially acquired passive immunotherapy d) artificially acquired active immunity

b) naturally acquired passive immunity

Which of the following does not contain MHC II on its surface? a) lymphocyte b) red blood cell c) macrophage d) dendritic cell

b) red blood cell Red blood cells do not serve as antigen-presenting cells, so they do not express MHC class II molecules.

How are the lymphatic system and cardiovascular system similar or dissimilar? a) Blood capillaries are much more permeable than lymphatic capillaries. b)Lymph is similar in composition to blood plasma. c) Both blood vessels and lymphatic vessels have a pump to circulate fluids. d) Both blood vessels and lymphatic vessels are circulatory systems.

b)Lymph is similar in composition to blood plasma.

How is the result of clonal expansion of activated B cells different than or similar to the clonal expansion of T cells? a) Like activated T cells, activated B cells are self-stimulatory. b) Clonal expansion of activated B cells does not require the involvement of helper T cells. c) Clonal expansion of activated B cells results in the production of memory B cells and plasma cells, while the clonal expansion of activated T cells results in the production of memory T cells and cytotoxic T cells. d) Both T cells and B cells are activated by Th1 cells.

c) Clonal expansion of activated B cells results in the production of memory B cells and plasma cells, while the clonal expansion of activated T cells results in the production of memory T cells and cytotoxic T cells.

Which of the following is not associated with killing by a cytotoxic T cell? a) perforin b) granzyme c) IL-4 d) CD95

c) IL-4 IL-4 is used by helper T cells to stimulate B cells.

The major class of immunoglobulin found on the surfaces of the walls of the intestines and airways is secretory ______. a) IgG b) IgM c) IgA d) IgE e) IgD

c) IgA

Which of the following is true about IgG? a) It stimulates a single immune responses. b) It is restricted to effects inside the vascular system. c) It is the most common antibody class. d) It cannot cross the placenta to protect an unborn fetus.

c) It is the most common antibody class.

In regard to antibody function, identify the MISMATCHED pair. a) neutralization = covering a critical portion of a toxin so that it is no longer harmful b) antibody-dependent cell-mediated cytotoxicity = target cell dies by apoptosis c) agglutination = antibodies bind microbes to the vessel walls, inhibiting spread of the microbe d) opsonization = simulates phagocytosis

c) agglutination = antibodies bind microbes to the vessel walls, inhibiting spread of the microbe Agglutination causes soluble molecules to become insoluble, which may target them for phagocytosis or filtering by the kidneys.

Once an inactive cytotoxic T cell recognizes and binds to an epitope that is presented by a dendritic cell, what type of cell activates the T cell, resulting in clonal expansion? a) A B lymphocyte b) A cytotoxic T cell c) A suppressor T cell d) A helper T cell

d) A helper T cell

Which of the following statements is true? a) Memory B cells are typically established when the B cell binds to an antigen. b) Adaptive defenses include humoral immunity only. c) Innate defenses are enough to keep a person healthly. d) Adaptive defenses include both humoral and cellular immunity.

d) Adaptive defenses include both humoral and cellular immunity.

What is meant by the clonal expansion of a B cell? a) An activated B cell will kill infected host cells. b) An activated B cell will engulf and digest anything foreign. c) An activated B cell will immediately begin to produce antibodies. d) An activated B cell divides into cells that give rise to memory B cells and plasma cells.

d) An activated B cell divides into cells that give rise to memory B cells and plasma cells.

Which cells express MHC Class I molecules in a patient? a) red blood cells b) antigen-presenting cells only c) neutrophils only d) all nucleated cells e) dendritic cells only

d) all nucleated cells

Among the key molecules that control cell-mediated cytotoxicity are a) perforin b) immunoglobulins c) complement d) cytokines e) interferons

d) cytokines

MHC class II molecules bind to ________ and trigger _______. a) endogenous antigens; cytotoxic T cells b) exogenous antigens; cytotoxic T cells c) endogenous antigens; helper T cells d) exogenous antigens; helper T cells

d) exogenous antigens; helper T cells

Rejection of a foreign skin graft is an example of _________. a) destruction of virus-infected cells b) tolerance c) antibody-mediated immunity d) a secondary immune response e) a cell-mediated immune response

e) a cell-mediated immune response

In which of the following sites in the body can B cells be found? a) lymph nodes b) spleen c) red bone marrow d) intestinal wall e) all of the above

e) all of the above

What is the TERM for certain 3-D regions of an antigen molecule that stimulate immune responses

epitopes

What part of an antigen is recognized by an immune receptor?

epitopes

T-cells act against body cells that harbor ________ pathogens, like viruses, AND against body cells that produce _____ antigens like cancer cells.

intracellular pathogens abnormal antigens

What are the primary and secondary lymphatic organs?

primary: red bone marrow, thymus secondary: lymph nodes, spleen, tonsils, MALT

What is the FUNCTION of MHC proteins in the immune system?

proteins in cytoplasm which function to hold and position epitopes for PRESENTATION to immune cells

Define Cytokines

regulatory proteins that act as intercellular signals/messages when released by certain body cells. Chemicals released by the immune system communicate with the brain.

What is the major function of B and T cell lymphocytes?

secretion of antibodies

Although very similar, describe how clonal deletion of B-cells is DIFFERENT from clonal deletion of T-cells.

self-reactive B-cells "may" become inactive or change their BCR rather than undergoing apoptosis

Describe the inducibility characteristic of adaptive immunity?

specific antigens activate or induces cells of the adaptive immune system

Which part(s) of B-cell receptors form the antigen-binding sites?

the end of the heavy chain and the end of the light chain