Inhibitory activity of HIV envelope gp120 dominates over its antigenicity for human T cells.
HIV-1 envelope glycoprotein (gp120), as a CD4-binding reactant, has been shown to inhibit in its native form human T cell responses to several antigens. Here we show that gp120 in soluble form also inhibits activation of a specific human T cell line that responds to gp120-pulsed autologous antigen-presenting cells. In addition the inhibitory property of gp120 for antigen-driven T cell proliferation depends upon its ability to bind CD4 and is lost when CD4-binding capacity is abolished by denaturation, or blocked by complexing with soluble CD4 or with polyclonal antibodies. In contrast, antigenicity of denatured or complexed gp120 for specific human T cells is preserved. Similar effects are also observed with another CD4-binding reactant (i.e. anti-Leu 3a MoAb), which stimulates and/or inhibits human T cells specific for mouse immunoglobulins depending on native or denatured conformation.
Manca
F
F
Department of Immunology, University of Genoa, San Martino Hospital, Italy.
Walker
L
L
Newell
A
A
Celada
F
F
Habeshaw
J A
JA
Dalgleish
A G
AG
D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation / Q000502:physiology; D015704:CD4 Antigens / Q000502:physiology; D002460:Cell Line; D002999:Clone Cells; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D011489:Protein Denaturation; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120