43. Humoral Immune Response I

Question 1

A scientist is study the humoral mediated immune system an B-cell activation. His superior wants him to run experiments on TI-2 B cell receptor activation what of the listed would cause activation?

A. Blimp-1
B. Bacterial Flagella
C. CD8 Cells
D. Lipopolysaccharide

RFA

Answer 1

Ans. B- TI-2 are activated by highly repetitious molecules such as Bacterial Flagella

A. Blimp-1- is a repressor gene that is associated with B cell proliferation

C. Cytotoxic T Cells (CD8) T cells- do not help with B cell activation CD4, Helper Cells do

D. Lipopolysaccharides- activate TI-1 not TI-2

Question 2

A patient suffers from a autoimmune condition after studies it is found that the B-cells are over responsive and are failing to be deactivated. Which of the following may the patient lack?

A. AID
B. CD21
C. CD22
D. CXCR5
E. TAPA-1

RFA

Answer 2

ANS C. CD22- cytoplasmic tail for signal transduction, contains ITIM (immunoreceptor tyrosine inhibitory motif), which functions to deactivate B cells, it is important in prevent autoimmunity

A. AID- Activation Induced cytidine deaminase- creates muation in DNA by deamination of cytosine base, immportant in Affinity Maturation and Class Switching,

B. CD21- important in innate immune system works with CR2 to bind with C3d (on microbes) , enhances antigen dependent activation of B-cells

D. CXCR5- expressed by T cells and draws cells to the follicles

E. TAPA-1- is a B cell co-receptor, it is a transmembrane molecule

Question 3

Which of the following is responsible for signal 2 activation?

A. Interaction of B7 and CD28
B. Interaction of CD40 and CD 40L
C. Ig-alpha and Ig-beta 
D. CD22  
E. CR2

SZ

Answer 3

Ans. B Interaction of CD40 and CD40L

A. B7-CD28 provides costimulation to the T helper cells
C. Ig-alpha and Ig-beta are receptors that help tranduce signal 1
D. CD 22 is an inhibitor co-receptor
E. CR2 is a receptor for C3d complement

Question 4

Which of the following is required for class switching?

A. CXCR5
B. AID enzyme
C. ICOS
D. CD40 &CD40L
E. A&C
F. B&D
G. All of the above

SZ

Answer 4

Ans. F     AID and CD40/CD40L
are both required for class switching. 

If there isn’t CD40L than only IgM, X-linked hyper M syndrome.

CXCR5 helps draw cells to the follicles. ICOS helps generate the functional follicular helper T cells.