BIO210Y5 Lecture 6: The Immune Response 1

1. Neutralizing antibodies are effective at preventing
infection or toxicity mediated by pathogens or their toxic products. In fact, nearly all vaccines currently in use function by eliciting neutralizing antibodies. The most important feature of a neutralizing antibody is:
A. Having a high degree of multi-valency, such as being a pentamer or hexamer of immunoglobulin monomers
B. Having high affinity for the antigen
C. Being present at a high concentration in the circulation
D. Being efficient at activating the complement cascade
E. Having a long half-life in the body

2. IgM antibodies are much more efficient than IgG at activating the complement cascade. However, under certain circumstances, IgG antibodies will activate the complement pathway. One example of a situation in which IgG binding to its antigen will
NOT trigger the complement cascade is when:
A. The IgG antibodies bind to a multivalent soluble antigen in solution, such as a polysaccharide structure shed from a bacterial pathogen.
B. The IgG antibodies bind to a viral capsid protein that is present in more than 100 copies on the viral particle surface.
C. The IgG antibodies bind to a bacterial surface by recognizing a repetitive polysaccharide component of the bacterial capsule.
D. The IgG antibodies are binding self-antigens such as chromatin released from dead cells.
E. The IgG antibodies are neutralizing a bacterial toxin protein by blocking the receptor-attachment site on the toxin.

3. Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important effector mechanism in immunity to virus infections. This immune pathway has also been exploited for clinical applications. For instance, patients with
various disorders, including rheumatoid arthritis and some B cell lymphomas, are treated with an antibody directed at CD20, a surface receptor expressed on all B cells. This antibody leads to the depletion of B cells from the patients by the actions of:
A. Natural killer (NK) cells
B. Cytotoxic CD8 T cells
C. Cytotoxic CD4 T cells
D. Activated macrophages
E. The complement cascade membrane attack complex

1. Why is the process of gene rearrangement used in creating antibodies and T-cell receptors (TCRs) so important?

A. This is how our systems produce memory of pervious exposures, a key trait in adaptive immune responses.

B. Without it, we would need a single gene for every antibody and TCR required to mount all the possible responses need ed during our lives

C. interactions with antigens stimulate cells to initiate these processes, building the best and strongest response possible to the antigen

D. this is the same DNA altering process that leads to cancer. Understanding it leads to better treatments for cancer

2. Which of the following is NOT an antimicrobial substance?

A. keratin

B. Lysozyme

C. Defensins

D. Lactoferrins

E. Peroxidases

3. Which of the following is NOT an outcome of fever?

A. Direct destruction of microbes

B. increased release of pro-inflammatory cytokines

C. increased production of lymphocytes

D. increased phagocytic killing by leukocytes

E. increased production of interferons

4. Which of the following pattern recognition receptors is/are anchored in the host cell membrane?

A. Only C-type lectin receptors (CLRs)

B. Only RIG-like receptors (RLRs)

C. TLR and CLRs

D. Only toll-like receptors (TLRs)

E. NLRs and RLRs

F. Only NOD-like receptors (NLRs)

5. Fever allows the body to fight microbial invaders by which of the following mechanisms?

A.Fever plays all of these roles in the body

B. Fever prevents microbes with lower optimum temperatures from growing, giving the immune system time to eliminate those cells

C. Fever increases the inflammatory response, but reduces the production of interferons unless the invader is a dsRNA virus

D. A moderate fever reduces the inflammatory response but stimulates phagocytic activity in neutrophils and eosinophils

E. Fever increases the multiplication of lymphocytes and enhances the release of substances that attract basophils that then engulf the microbial invader

6. According to the clonal selection theory

A. Each B cell is already programmed to produce a specific antibody

B. B cells producing autoantibodies are eliminated in the thymus

C. Self-reactive T cells are killed in the thymus AND B cells producingautoantibodies are eliminated in the thymus

D. Seld-reactive T cells are killed in the thymus

7. Apoptosis

A. is a form of programmed cell death AND is induced in target cells by effector T cytotoxic cells

B. refers to the transformation of B cells into plasma cells

C. is induced in target cells by effector T cytotoxic cell AND results specifically in T cell death

D. results specifically in T cell death AND refers to the transformation of B cells into plama cells

8.

HI HELP PLEASE I NEED ANSWERS TO ALL QUESTIONS PLEASE THANKS

1. during inflamation fluid will passively diffuse out of blod vessels into the nearby infected tissue. This implies all of the following EXCEPT

a.the osmolarity of the fluid surrounding infected tissues is higher than the plasma b the surrounding tissue will swell with excessive fluids c near by cappilaries have become more pearmeable d B-lymphocyte will differeniate to become plasma cell

2. which of the following best describe the qualities of most antigens?

a macromolecules that are foreign to the host b atomic elements that are not normally present in the human body c macromolecules tah tare produced by the host organism d atomic elements that are harmful or toxic

3. an adbantages to adaptive immunity is

a its memory cell that provide quicker larger and more efficient immune response upon second exposure to an antigen b its need for several cells to be activated over several days on first exposure c the ability for its individul cells to respond to many differnt pathogens d the use of antibodies that cause cells lysis and kill invading cells

4, an advantages of innate immunity is

a its a barrier taht prevent pathogens from entering into the body b the specifcity of its individual cell which specialize in the removal on one type of antigen c the numerous step in the activation of its cell that can prevent autoimmune disease d the use of the antibodies to cause cell lysis and kill invading cell

5. B- lymphocytes are categorized as part of the adaptive branch of the immune sys for all of the following reason but one Which of the following is NOT one part of reason B lyphocytes are considered part of the adaptive immunity?

a they produce memory cell when activated b their receptors will bind to only one antigen c they require costimulation from an activated T helper cell d thet are a first line of defense that can begin killing

6. Over lap in the innate and adaptive immune sys is seen in all of the following examples but one Which of the following examples does NOT illustrate the over lap of innate and adaptive immune resposes ??? adendritic cell presenting antigen on their MHC II proteins to T helper cells b macrophage becoming activated macrophages in response to cytokines realesed by T helper cells c natural killer cell causing of an abnoraml host cell lacking MHC proteins d Plasma cell that produce large amounts of IgE that will ultimetly allow mast cell to relase histamine

7. Which of the following examples below describe an autoimmune disease? a infection and death of T helper cells bya virus resulting in a loss of adaptive immunity b realse of bacterial endotoxins that block acetylcholine realse result is muscle paralysis c antibody binding to acetylcholine receptors of hte motor end palte resulting in muscle weakness.d uncontrolled cell division resulting in cell surface abnormalities recognized by natural killer cell.

8. Which of he following does NOT describe actions of interferon IFN? a virally infected cell can release interferon which attracts natural killer cell to attack and kill the IFN secreting cell b IFN binds to normal uninfected cell stimulating the activation of genes that produce anti viral proteins c IFN will attract macrophages to the secreting cell to be removed bt phagocytosis d IFN can penetrate the virla capsid and destroy the virus