Exam 3 inclass examples

Question 1

Macrophage activation by Th1 cells is an important immune mechanism for eliminating bacteria which can resist……

Answer 1

lysosomal degradation

Question 2

T-Cells which activate macrophages do all of the following except.

Answer 2

provide granzymes that the macrophages use to kill it.

Question 3

Th1 cells make IL-3 and GM-CSF which:

Answer 3

stimulate macrophage production in the bone marrow.

Question 4

Which of the following statements about primary and secondary antibody responses is NOT true?

Answer 4

Primary responses are characterized by IgG antibodies, whereas secondary responses are dominated by IgM antibodies.

Question 5

Which one of the following statements about humoral immune responses is true?

Answer 5

Naive B cells are required for initiation of primary responses and memory B-Cells are required for initiation of secondary responses.

Question 6

Which of the following events does not occur withing germinal centers?

Answer 6

Ig Gene V(d)J recombination.

Extra note: Variable part of IgG recombines in bone marrow.

Question 7

Which of the following antigenic structures might activate B-Cell antibody production without the aid of T-Cells?

Answer 7

ABO blood group antigen (oligosaccharide)

Question 8

Which of the following statements accurately describes antigen recognition events in a lymph node during a helper T-Cell dependent antibody response to a protein antigen?

Answer 8

Naive B-cells recognize intact proteins, generate peptide fragments of these proteins, and present them in complexes with MHC molecules to differentiated helper T-cells

Question 9

A 5-year-old boy has a history of recurrent pneumococcal pneumonia. Pneumocystis carinli pneumonia (PCP), and bacterial ear infection. His maternal uncle and an older brother experienced the same symptoms, but he has an older sister who is healthy. Laboratory studies indicate normal number of B cells and T cells, and the serum contains mostly IgM and very little IgG. Which of the following genes most likely contains a mutation in this patient?

Answer 9

CD40 and CD40L

Question 10

The B cell receptor (BCR) complex and the signaling cascades to which it is linked share many similarities with the T cell receptor (TCR) complex and its linked signaling cascades. Which of the following comparisons between BCR and TCR signaling is NOT true?

Answer 10

CD4/CD8 coreceptors in T cell and the CR2 coreceptor in B cells both enhance responses to antigen by a PI3 kinase– dependent mechanism.

Question 11

A 5-year-old boy has a history of recurrent pneumococcal pneumonia. Pneumocystis carinli pneumonia (PCP), and bacterial ear infection. His maternal uncle and an older brother experienced the same symptoms, but he has an older sister who is healthy. Laboratory studies indicate normal number of B cells and T cells, and the serum contains mostly IgM and very little IgG. Which of the follwing abnormalities would NOT be likely in this patient?

Answer 11

There is limited diversity in the repertoire of IgM antibodies produced.

Question 12

Concerning the Fab region of an antibody molecule, which of the following is TRUE?

Answer 12

the Fab includes the entire V and C regions of the light chain.

Question 13

Many cell surface molecules are important in the activation of B lymphocytes to produce antibody. Which of these is NOT however involved during the actual binding of B cells to the T helper cell surface?

Answer 13

Ig

Question 14

IF you could analyze at the molecular level, a plasma cell making IgA antibody, you would find all of the following except…

Answer 14

mRNA specific for u(MU) heavy chains.

Question 15

Within the germinal centers of secondary lymphoid organs

Answer 15

B cells expressing affinity for antigen are rescued from cell death by binding to antigen-binding complexes on follicular dendritic cells.

Question 16

The mechanism most responsible for co-expression of IgM and IgD on the surface of a B cell clone is

Answer 16

Alternative RNA splicing.

Question 17

The switch from membrane bound to the secreted form of Ig involves

Answer 17

Alternative splicing and

Polyadenylation of mRNA which excludes the transmembrane coding sequences found in the genomic DNA

Question 18

Multiple myeloma is a cancer which has arisen from a

Answer 18

plasma cell

Question 19

Which of the following is TRUE about effector functions and immunoglobulins?

Answer 19

If B cell membrane Ig binds to soluble complexes of antigen and antibody, B cells may be down-regulated.

Question 20

Complementarity determining regions (CDR’s) of an immunoglobulin

Answer 20

determine antibody specificity and are found on both the heavy and the light chains.

Question 21

If you wanted to check for the presence of memory B cells from your vaccine ??????? by taking some of their B cells and re-stimulating them in vitro ????? antigen, the best place to get some memory cells would be from

Answer 21

blood

Question 22

After binding to its specific antigen, a B lymphocyte may switch to

Answer 22

Immunoglobulin heavy-chain class

Question 23

C3a and C5a can cause

Answer 23

vascular permeability

Question 24

Patients with severely reduced C3 levels tend to have

Answer 24

increased number of severe bacterial infections.

Question 25

Individuals with a genetic deficiency of C6 have

Answer 25

Decreased resistance to Neisseria bacteremia

Question 26

The membrane IgM and IgD on the surface of an individual B cell

Answer 26

are identical except for their CH regions.