Step I MHC Class question

[Ronin786]

Silly question:

If MHC Class I is found on all nucleated cells other than RBCs, and MHC Class II is found only on APCs (which are also nucleated) then do APCs have both MHC Class I and II on their surface?

Couldn't find anything anywhere else, so thanks in advance.

 

[MrBigglesworth]

Yes they do. (Levinson Chapter 62, page 415.)

Also, a way to remember is with EBV (mono). The infected B-cell is cleared with cell-mediated lysis.

http://www.atsu.edu/faculty/chamberlain/Website/lectures/lecture/mono.htm

 

[mdeast]

Yes they do. (Levinson Chapter 62, page 415.)

Also, a way to remember is with EBV (mono). The infected B-cell is cleared with cell-mediated lysis.

http://www.atsu.edu/faculty/chamberlain/Website/lectures/lecture/mono.htm

Yup! Definitely need MHC Class I for both antigen presentation (if virally infected) as well as for avoiding being eliminated by NK cells.

 

[Morsetlis]

The process is termed cross-presentation.

Note that MHC I - peptide presentation to CD8+ cells leads to cell-mediated lysis and no formation of memory cell or Th activation. MHC I presentation to NK cells activate KIR (inhibitory) and prevent cell-mediated lysis.

http://www.ncbi.nlm.nih.gov/pubmed/12224504

"The existence of these proteins indicates the importance of class II-mediated presentation of endogenous antigens in signalling virus infection to CD4+ T cells."

In a roundabout way, MCH II inhibition by viral proteins show that there is some (undemonstrated?) processing of exogenous viral particles by MCH II mechanisms in APCs. Typically, we would think of MCH I - peptide presentation as processing of endogenous viral particles by nucleated cells, themselves.