Cmh 1

[Anasouma]

all nucleated cells have CMH 1 on their surface so that they can present endogenous peptides to CD8+ is that mean that all nucleated cells are antigen presentation cells?

[Dr. X]

my take is that.. you need to know the difference between "APC" and "virus-infected cell". In APC, they phagocytose the bacteria (think of it as Defense). In Virus-inf. cell (all nucleated cells), are susceptibe to virus invasion (think of it as offense from virus side).

For it to be a APC - (Macrophage, dendritic cell, B-lymph = Defenders) - they have both MHC I and MHC II. They present the "antigen" (exogenous), basically a piece of bacteria, say take bacteria's leg and point it outside of the cell. This causes a huge ruckus and MHC II, being predominant works with CD4 on T-helpers (the british) to initiate a response. The big boys IL-2 and y-interfons (the americans called by british) come to the rescue. IL-2 itself brings the T-cytoxic (canadians) as well for support.

virus-infected cell.. (all nucleated cell for that matter) have MHC I only and interact with CD8. Note that they take either the virus's protein or make their own peptide (endogenous) -like a made Red FLAG and point it out of the cell) - CD8, T-cytoxic (canadians) comes to the rescue.

the answer i was going for is that all nucleated cells are not APC's.

[IMG SURVIVOR]

That is so beutifull, standing ovasion for you.
1- What is APC?

[Dr. X]

:marines: no prob. img.

apc - anitgen presenting cell