Chapter 10: Preventing Infection At Mucosal Surfaces

Question 1

Three parts to body’s defense agains infection

Answer 1

• Innate and adaptive immunity
• preventing infection (ex. Mucosal tissues)
• immunological memory and secondary immune response
• bridging innate and adaptive immunity (help each other)

Question 2

Mucosae

Answer 2

• is everywhere in our body

- anywhere where air comes into contact with tissue, mucous must be there

Question 3

Gastrointestinal tract

Answer 3

• activities such as immunological, food adsorption, takes place

Question 4

Ring of Lymphoid Organs

Answer 4

• guards the entrance to the gastrointestinal and respiratory tracts (Waldeyer’s Ring)

Question 5

Lymphoid Follicles

Answer 5

• present in the gut wall along with lymphoid tissue

Question 6

Microfold cells (M cells)

Answer 6

• and dendritic cells facilitate transport of microbes from the gut lumen to gut-associated lymphoid tissue
• adaptive immune responses in the gut are initiated and maintained by M cells that sample the gut’s content

Question 7

Mucins

Answer 7

• are gigantic glycoproteins that endow the mucus with properties to protect epithelial surfaces

Question 8

Gut-Associated Lymphoid Tissues

Answer 8

• has fingerlike processes (villi) covered by a layer of thin epithelial cells that are specialized for the uptake and further breakdown of already partly degraded food coming from the stomach

Question 9

How are adaptive immune responses in the gut initiated and maintained?

Answer 9

• by M cells that sample the gut’s content
• they deliver this material to pockets on the basolateral side of the M-cell membrane
• here, dendritic cells and B cells take up antigen and stimulate the proliferation and differentiation of antigen specific T cells

Question 10

Effector Lymphocytes populate healthy ___________ tissue in the absence of infection

Answer 10

• mucosal

Question 11

Most immune-system cells in mucosal tissues are activated ______________ ________.

Answer 11

• effector cells

Question 12

Outside the lymphoid tissues, the gut ____________ contains ________ T cells

Answer 12

• epithelium

- CD8

Question 13

The lamina propria is well populated with _______ T cells, __________ T cells, __________ cells, ________ cells, ___________ cells, and ___________.

Answer 13

• CD4
• CD8
• Mast
• Plasma
• Dendritic
• Macrophages

Question 14

Dendritic cells can extend across epithelial cells to retrieve ____________.

Answer 14

• antigens

Question 15

Dimeric IgA and Pentameric IgM binds ____________ at various sites in mucosal tissues to take care of business.

Answer 15

• pathogens

Question 16

Humans with selective deficiency of IgA do not succumb to infection. Why?

Answer 16

• in IgA deficiency the lack of IgA is compensated for by increased productions of other isotypes (IgM)

Question 17

IgM and IgA can be transported to the other side with the help of a…

Answer 17

• poly-Ig Receptor

- uses the J chain to safely transport Igs

Question 18

Intestinal helminth infections provoke strong TH2 mediated immune responses

Answer 18

• feature of CD4 T cell responses to intestinal helminths is that they can polarize, becoming either a protective TH2 response or a TH1 response that augments the disease and discomfort of the human host
• TH2 responses can lead to expulsion of the parasite, whereas TH1 responses lead to persistent infection and chronic inflammation of the intestine