Lecture 9: The mucosal immune system
1) What does MALT stand for? Why is a mucosal immunity important?
2) What is payer’s pitch?
3) Explain the process of how MALT cells help in the production of antiinflammatory response
and the activation of NK/DC/Macrophages.
4) What are IEL that are found in the GALT ( gut associaited)?
5) How does IEL kill/ offer protection? ( explain the step)?
6) What cytokines do Th cells makes in the MALT that causes the differentiation of the
proliferating B cell ( centrocytes ) into an IgA and IgG2b producing plasma cell?
7) What are the two cytokines that the Th3 cells make in MALT? Reponses?
8) Even though we have so many foreign things in ours guts, why are we not getting sick?
9) What is oral tolerance? Explain using experiment as well.
10) How does oral tolerance happen?
11) What are the roles of the T req cells? What are on their surface?
12) How does the T req cell stop macrophages?
13)What is the difference between the oral and the protective immunity?
14) What are the commensal bacteria? What changes their levels?
15) How does the body decide to produce Th1/2 vs Th3 or requlatory response? Lecture 9: The mucosal immune system
1) MALT = mucosaassociated lymphoid tissue. They are very important to protect because
these are the very first line of defense and the first barrier that bugs need to cross.
2) T,B,DC cells, and Macrophages that are found in these patches. Pathogens that enters inside
through the MALT or through the gut stopped by them.
3) M cells take up antigen by endocytosis and phagocytosis ▯Antigen is transported across the M
cells in vesicles and released at the basal surface ▯Antigen is bound by dendritic cells, which
activate T cells ▯ Endocytosed bacteria are recognized by TLRs in intracellular vesicles ▯they
are also Bacteria or their products directly entering the cytosol are recognized by NOD1 and
NOD2▯ TLRs, NOD1 and NOD2 activate NFκB, inducing the epithelial cell to express a
number of inflammatory cytokines, chemokine’s and other mediators. These in turn activate
neutrophils, macrophages and dendritic cells .
4) They are basically stuff on the epithelial surface of the GALT or MALT. Unlike other T cells
IELs do not need priming. Upon encountering antigens, they immediately release cytokines
and cause killing (CD8) of infected target cells.
5) Virus infects by crossing the epithelial layer displays viral peptide to CD8 IEL via MHC