55-kDa antigens found on HELPER-INDUCER T-LYMPHOCYTES and on a variety of other immune cell types. They are members of the immunoglobulin supergene family and are implicated as associative recognition elements in MAJOR HISTOCOMPATIBILITY COMPLEX class II-restricted immune responses. On T-lymphocytes they define the helper/inducer subset. T4 antigens also serve as INTERLEUKIN-15 receptors and bind to the HIV receptors, binding directly to the HIV ENVELOPE PROTEIN GP120.

Synonyms: Surface CD4 Receptor, Antigens, CD4, CD4 Antigen, Antigen, CD4, Receptors, CD4, CD4 Antigens, CD4 Receptors, Antigens, T-Cell T4, T-Cell T4 Antigens, T4 Antigens, T Cell, 0, T4 Antigens, T-Cell, Surface CD4 Receptors, CD4 Receptor, Surface, CD4 Receptors, Surface, CD4 Molecule, Receptors, Surface CD4