Journal Article

CD4 on CD8+T Cells Directly Enhances Effector Function and Is a Target for HIV Infection

Whitmire, Jason K., LaForge, Stuart, Christina M. R. Kitchen, Kitchen, Scott G., Zack, Jerome A., Galic, Zoran, Brown, Stephen J., Coffin, John M., Jones, Nicole R., Vu, Bien-Aimee, Brooks, David G.

2004

Overview

Costimulation of purified CD8+T lymphocytes induces de novo expression of CD4, suggesting a previously unrecognized function for this molecule in the immune response. Here, we report that the CD4 molecule plays a direct role in CD8+T cell function by modulating expression of IFN-γ and Fas ligand, two important CD8+T cell effector molecules. CD4 expression also allows infection of CD8 cells by HIV, which results in down-regulation of the CD4 molecule and impairs the induction of IFN-γ, Fas ligand, and the cytotoxic responses of activated CD8+T cells. Thus, the CD4 molecule plays a direct role in CD8 T cell function, and infection of these cells by HIV provides an additional reservoir for the virus and also may contribute to the immunodeficiency seen in HIV disease.

• Publisher: National Academy of Sciences,National Acad Sciences
• Subject: Antigen presenting cells / B lymphocytes / Biological Sciences / CD4 Antigens - metabolism / CD8-Positive T-Lymphocytes - immunology / Cells / Cytotoxicity, Immunologic / Dendritic cells / Fas Ligand Protein / HIV / HIV infections / HIV Infections - immunology / Human immunodeficiency virus / Humans / Immune response / Immunology / In Vitro Techniques / Infections / Interferon-gamma - metabolism / Ligation / Lymphocytes / Membrane Glycoproteins - metabolism / Microbiology / Models, Immunological / Molecules / T lymphocytes / T-Lymphocytes, Cytotoxic - immunology / Viruses