Cutting Edge: Epitope-dependent effect of Nef-mediated HLA class I down-regulation on ability of HIV-1-specific CTLs to suppress HIV-1 replication.

Journal of Immunology (Baltimore, Md. : 1950)

PubMedID: 15611225

Tomiyama H, Fujiwara M, Oka S, Takiguchi M. Cutting Edge: Epitope-dependent effect of Nef-mediated HLA class I down-regulation on ability of HIV-1-specific CTLs to suppress HIV-1 replication. J Immunol. 2005;174(1):36-40.
It is believed that Nef-mediated HLA class I down-regulation is one of the mechanisms that allow HIV-1-infected cells to escape from being killed by HIV-1-specific human CTLs. In this study, we show that the effect of Nef-mediated HLA class I down-regulation on the ability of HIV-1-specific CTLs to suppress HIV-1 replication is epitope dependent. The CTLs specific for two Pol epitopes presented by HLA-B*5101, one of the HLA alleles associated with slow progression to AIDS, effectively killed HIV-1-infected CD4+ T cells and suppressed HIV-1 replication. In contrast, those specific for the other four epitopes failed to kill HIV-1-infected CD4+ T cells and partially or hardly suppressed HIV-1 replication. The difference of the ability between these two types of CTLs may result from the difference of the number of HLA class I epitope complex on the surface of NL-432-infected CD4+ T cells.