A human CD4+ T-cell line expresses functional CD64 (Fc gamma RI), CD32 (Fc gamma RII), and CD16 (Fc gamma RIII) receptors but these do not enhance the infectivity of HIV-1-IgG complexes.
T cells do not generally express Fc receptors (FcRs). However, we report here that C8166 cells, a human CD4+ T lymphoblastoid cell line, widely used in research into the human immunodeficiency virus type 1 (HIV-1), expressed CD64 (Fc gamma RI), CD32 (Fc gamma RII), and CD16 (Fc gamma RIII) on the plasma membrane as shown by immunostaining with specific monoclonal antibody fragments. Another human CD4+ T lymphoblastoid cell line. H9, expressed none of these FcRs. C8166 cells bound monomeric normal rat serum IgG in a dose-dependent manner, and when saturated bound heat-complexed immunoglobulin G (IgG) also dose dependently. These observations are consistent with the presence on the C8166 T-cell line of both high- and low-affinity Fc gamma Rs. Fc gamma Rs are putative receptors for virus-IgG complexes, but in this study did not enhance infectivity of HIV-1 complexed with a human neutralizing mAb or three rat neutralizing mAbs. Virus complexed with a non-neutralizing mouse mAb was unable to infect cells using Fc gamma Rs as receptors after CD4 was blocked with a specific anti-CD4 mAb.
McLain
L
L
Department of Biological Sciences, University of Warwick, Coventry, UK.
Dimmock
N J
NJ
D000936:Antigen-Antibody Complex / Q000276:immunology* / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D015483:HIV Antibodies / Q000276:immunology; D015658:HIV Infections / Q000276:immunology; D015497:HIV-1 / Q000472:pathogenicity*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D011489:Protein Denaturation; D017452:Receptors, IgG / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000936:Antigen-Antibody Complex; D015483:HIV Antibodies; D007074:Immunoglobulin G; D017452:Receptors, IgG