TBL 1 - Mucosal Immunity

Question 1

which of the following is a true statement about M cells in the gut?

a. derive their name from mucus
b. located in the dome area of Peter’s patches
c. protected by a thick glycocalyx
d. participate in antigen processing and presentation

Answer 1

b. located in the dome area of Peter’s patches

Question 2

which of the following is a true statement regarding the role of dendritic cells in the mucosal immune system?

a. present commensal organisms to Ag-specific T cells and B cells to induce Ag-specific secretory IgA
b. quickly induce inflammation to contain infection
c. present food antigens to Ag specific T cells and B cells to induce Ag-specific serum IgA
d. quickly induce tolerance to an invasive pathogen

Answer 2

a. present commensal organisms to Ag-specific T cells and B cells to induce Ag-specific secretory IgA

Question 3

which of the following immunoglobulin types binds the poly-Ig receptor the way that IgA does?

a. IgG
b. IgE
c. IgD
d. IgM

Answer 3

d. IgM

Question 4

which of the following is true regarding IgA?

a. secretory IgA activates the classical complement pathway and facilitates phagocytosis
b. intestinal secretions of healthy animals contain secretory IgA specific for commensal organisms
c. IgA is secreted as a dimeric molecule by M cells on the intestinal mucosa
d. dimeric IgA on the intestinal mucosa is cleaved into two monomeric IgA molecules

Answer 4

b. intestinal secretions of healthy animals contain secretory IgA specific for commensal organisms

Question 5

a naive B cell is activated by a specific antigen in the mucosa of the GI tract, where and in what form will the specific IgA occur?

a. monomeric IgA in milk and serum
b. monomeric IgA in milk and respiratory secretions
c. dimeric IgA in milk and respiratory secretions
d. dimeric IgA in milk and serum

Answer 5

c. dimeric IgA in milk and respiratory secretions

Question 6

the significance of MAdCAM-1 on the endothelium of blood vessels is that it binds to which of the following?

a. the integrin a4B7 on effector lymphocytes homing to mucosal tissues
b. dendritic cells, and causes the up-regulation of antigen processing and presentation
c. dendritic cells, and causes the down-regulation of antigen processing and presentation
d. the integrin a4B7 on naive lymphocytes homing to secondary lymphoid tissues

Answer 6

a. integrin a4B7 on effector lymphocytes homing to mucosal tissues

Question 7

which of the following statements regarding intestinal microbiota is true?

a. microbiota produce substances that favor the colonization of pathogenic microorganisms
b. commensal bacteria and pathogenic microorganisms induce similar mucosal immune responses
c. microbiota induce production of antimicrobial substances (defensins) through signaling by TLRs on epithelial cells
d. tolerance to organisms of the microbiota is induced in the systemic immune system

Answer 7

c. microbiota induce production of antimicrobial substances (defensins) through signaling by TLRs on epithelial cells

Question 8

mice and pigs reared in gnotobiotic conditions will display which of the following characteristics?

a. normal levels of sIgA in the gut lumen
b. poorly developed secondary lymphoid tissues in GI tract
c. well developed secondary lymphoid tissues in GI tract
d. elevated levels of sIgA in the gut lumen

Answer 8

b. poorly developed secondary lymphoid tissues in the GI tract