HLA-C and HLA-E reduce antibody-dependent natural killer cell-mediated cytotoxicity of HIV-infected primary T cell blasts.
OBJECTIVE
To determine whether the presence of HLA-C and HLA-E on HIV-infected cells modulates autologous natural killer (NK) cells from implementing antibody-dependent cell-mediated cytotoxicity (ADCC) of HIV-infected cells.


METHODS
The capability of HLA-C and HLA-E to control NK cell killing of HIV-infected autologous T cells coated with anti-gp120 monoclonal antibody was determined by blocking the interaction between the inhibitory receptors on NK cells and the MHC class I molecules on infected cells.


METHODS
Phytohemagglutinin-treated CD4 T cells were infected in vitro with HIV-1. Infected cells were separated from uninfected cells by removal of CD4 T cells. Infected cells were labeled with chromium-51, treated with a cocktail of four different monoclonal antibodies against HIV gp120, and co-cultured with freshly isolated autologous NK cells that were incubated with or without anti-CD159a, anti-CD158a, and CD158b, or all three antibodies combined. Killing of the HIV-infected cells by NK cells was assessed in a 4 h cytotoxic assay.


RESULTS
When the interaction between NK cell inhibitory receptors (i.e., CD158a, CD158b, and CD159a) and MHC class I molecules (i.e., HLA-C and HLA-E) on HIV-infected autologous T cells was blocked, a drastic increase in killing of anti-gp120-coated HIV-infected cells by NK cells was observed.


CONCLUSIONS
These studies indicate that the presence of HLA-C and HLA-E molecules on HIV-infected cells may facilitate evasion of NK-mediated killing of antibody-coated HIV-infected cells.
Department of Microbiology and Immunology, State University of New York, Upstate Medical University, Syracuse, New York 13210, USA.
Jeffrey P
JP
Ward
Matthew I
MI
Bonaparte
Edward
E
Barker
D015703:Antigens, CD / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005434:Flow Cytometry; D015699:HIV Envelope Protein gp120; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D015236:HLA-C Antigens / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D011961:Receptors, Fc / Q000276:immunology; D000097625:HLA-E Antigens
D015703:Antigens, CD; D015699:HIV Envelope Protein gp120; D006680:HLA Antigens; D015236:HLA-C Antigens; D015395:Histocompatibility Antigens Class I; D011961:Receptors, Fc; D000097625:HLA-E Antigens