shynra exam 3 set 2

Question 1

Extracellular Bacteria are optimally killed by

a. macrophages
b. complement
c. antibody
d. macrophages plus complement
e. macrophages plus antibody plus complement

Answer 1

e. macrophages plus antibody plus complement

Question 2

Opsonization of bacteria occurs through coating bacteria just with:

a. C3b
b. C8
c. membrane attack complex
d. F(ab’)2 IgG
e. IgM

Answer 2

a C3b

Question 3

extracellular bacteria try to avoid killing by:

a. activating neutrophils
b. accelerating complement activation
c. synthesizing capsules
d. by deviating complement deposition to the cell membrane
e. limiting variation in their antigens

Answer 3

d. by deviating complement deposition to the cell membrane

Question 4

CR1 complement receptors on phagocytic cells bind:

a. Factor H
b. Factor I
c. C3d
d. only inactive C3b (iC3b)
e. C3b

Answer 4

e. C3b

Question 5

iC3b binds to 
a. Factor H
B. C5 convertase 
c. CR1
d. CR2
E. C3 convertase

Answer 5

c. CR1

Question 6

Individuals lacking C8 or C9 are more prone to infections with the following type of bacteria:

a. Haemophilus influenzae
b. bacillus anthrax
c. Vibrio cholerae
d. Neisseria
e. Listeria monocytogenes

Answer 6

d. Neisseria

Question 7

Neutrophil chemotaxis is mediated by:

a. C5b
b. IL-8
c. C3a
d. CCL2
e. E-selectin

Answer 7

b. IL-8

Question 8

The membrane attack complex consists of:
a. OH
B Colicins 
c. C3b3b, Bb
d. C5b,6,7,8,9
e. Properdin

Answer 8

D. C5b, 6,7,8,9

Question 9

C3b

a. is chemotactic
b. is an anaphylatoxin
c. Opsonizes bacteria
d. directly injures bacteria
e. is the inactive form of C3

Answer 9

c. Opsonizes bacteria

Question 10

IgG antibodies:

a. are the earliest class to appear in an immune response
b. are normally dimeric in mucosal secretions
c. remain of low affinity
d. inhibit antibody responses through the Fc gamma receptor FcgRIIB1 on B-cells
e. Augment antibody responses through the Fc gamma receptor FcgRIIB1 on B-cells

Answer 10

d. inhibit antibody responses through the Fc gamma receptor FcgRIIB1 on B-cells

Question 11

Dendritic Cells can be driven from a resting state to an activated state by the T-cell surface molecule:
a. TCR
B. CD40L
c. CD28
D. B7
E. CD40

Answer 11

b. CD40L

Question 12

Which is the first of the following genes to be upregulated subsequent to T-cell activation 
a. transferrin receptor 
b. cytokine receptor 
c. cytokine 
d. c-myc 
e, VLA-1

Answer 12

d. c-myc

Question 13

Cytokines always act:

a. by binding to specific receptors
b. in an autocrine fashion
c. at long rang
d. antagonistically with other cytokines
e. synergistically with other cytokines

Answer 13

a. by binding to specific receptors

Question 14

A cytokines receptor which is a member of the hematopoietin receptor family is:

a. IL-8 receptor
b. IFN gamma receptor
c. TNF (TNF-alpha) receptor
d. IL-1 receptor
e. IL-2 receptor

Answer 14

e. IL-2 recepto

Question 15

IFN-gamma and TNF (TNF-alpha) can act synergistically:

a. to downregulate expression of MHC class I
b. because IFN-gamma downregulates expression of TNF receptors
c. to upregulate expression off MHC class II
d. because they both bind to the same receptor
e. because they cross-link IFN-gamma and TNF beta receptors

Answer 15

c. to upregulate expression off MHC class II

Question 16

Which og the following is characteristically produced by the Th2 CD4 cells which provide help for antibody production, but not by Th1 cells?

a. IFN-gamma
b. Lymphotoxin (TNF-beta)
c. GM-CSF
d. IL-4
e. IL-1

Answer 16

D. IL-4

Question 17

In the germinal center, B-cells become memory cells under the influence of:
A. CD40 
b. Cd23
C. Il-1 alpha 
d. IL-4
e. TGF beta

Answer 17

a. CD40

Question 18

high affinity B-cell clones in mammals are usually generated by

a. somatic hypermutation
b. expression of high affinity precursors in the virgin (naive) B-cell population
c. class switching
d. apoptosis
e. gene conversion

Answer 18

a somatic hypermutation

Question 19

Prior to class- switching, B-cells express

a. IgA alone
b. IgA and IgG
c. IgM and IgD
d. IgD alone
e. no surface Ig

Answer 19

c. IgM and IgD

Question 20

The specificity of antibody secreted by a B-cell may not be the same as that os the surface Ig of the clonal parent because of:

a. class switching
b. somatic hypermutation
c. allelic exclusion
d. alternative splicing
e. different heavy;light pairing

Answer 20

b somatic hypermutation

Question 21

In the thymic medulla the majority of gamma delta T-cells are:

a. CD4+CD8+
b. CD4+CD8-
c. CD4-CD8+
d. CD4-CD8-
e. Surface Ig+

Answer 21

d. CD4-CD8-

Question 22

The major long term source of a foreign antigen in the body is:

a. Anti-idiotype
b. complexes on the surface of follicular dendritic cells
c. antigen bound to the surface of B-cells
d. Antigenic peptides in the groove of MHC molecules
e. There are no long term sources of foreign antigen in the body

Answer 22

b. complexes on the surface of follicular dendritic cells

Question 23

Ctyokines:

a. are usually around 150-200 kDa
b. have glycosyl phosphatidylinositol )GPI_ anchors
c. can be pleiotropic
d. generally act at long range
e. produce very stable long-lived messenger RNA

Answer 23

c. can be pleiotropic

Question 24

Th1 cells secrete:
a. CD4
b. IL-4
c. IL-5
D. IL-6
e. Interferon-gamma

Answer 24

e. Interferon gamma

Question 25

Which one of the following cytokines can mediate release of acute phase proteins from the liver? a. IL-10 b. TGF- beta c. IL-6 d. IL-12 e. IL-8

Answer 25

c. IL-6

Question 26

``` Which og the following is not a feature of germinal center B-cells a. Immunoglobulin gene class switching b Apoptosis c, initial VDJ rearrangement d Somatic hypermutation e. Proliferation ```

Answer 26

c. Initial VDJ rearrangement

Question 27

Low amounts of antigen: a. produce low affinity antibodies b. do not influence the affinity of antibodies c. produce high affinity antibodies d. affect the avidity but not the affinity of antibodies e. preferentially induce class switching

Answer 27

c. produce high affinity antibodies

Question 28

The level of antigen a. is unrelated to the intensity of the immune response b. is related to the intensity of the immune response c. never has an effect on the response to a T-independent antigen d. has no effect on the concentration of MHC bound processes antigen

Answer 28

b. is related to the intensity of the immune response

Question 29

Memory T-cells a. Are continuously produce directly from naive progenitors without the need for antigenic stimulation b. express high levels of CD44 C. are only present in primary immune responses d. switch from an alpha beta to a gamma delta T-cell receptor e. express germ line Ig V genes

Answer 29

b. express high levels of CD44

Question 30

``` Activated memory T-cells can be distinguished from naive T-cells on the basis of expression of: a. T-cell receptor b. Immunoglobulin c. MHC class II molecules D. CD45RO e. IL-1 ```

Answer 30

D. CD45RO

Question 31

``` A major factor regulating the adaptive immune response is a. the neutrophil b. complement membrane attack complex c. C-reactive protein d. Antigen concentration e Haptoglobin ```

Answer 31

d. antigen concentration