Endocytosis of endogenously synthesized HIV-1 envelope protein. Mechanism and role in processing for association with class II MHC.

摘要: CD4+ T cell clones specific for the HIV-1 envelope (env) protein are able to recognize not only uninfected APC that have taken up and processed exogenous env protein, but also virally infected cells expressing protein. We evaluated hypothesis endocytosis of endogenously synthesized from plasma membrane permits entry into MHC class II-restricted Ag processing pathway. show here is internalized at a surprisingly high rate through mechanism dependent upon tyrosine-containing motif located in cytoplasmic domain gp41 subunit. Mutation critical tyrosine residue or truncation C-terminal portion resulted forms did undergo rapid internalization. However, by variety assays, these poorly were presentation as efficiently wild-type indicating internalization this pathway essential presentation. In addition, secreted form was presented II under conditions prevented re-uptake endocytosis. Taken together, results suggest although surface likely be major which association with MHC, an internal may used.