CD4 T lymphocyte

Detailed description

CD4 T lymphocytes express the surface protein CD4 and include various subgroups, such as T helper cells. Once activated, they can regulate other immune cells via signaling molecules and direct cell-to-cell contact. For example, they assist B cells in producing antibodies and promote the activity of other immune cells. HIV primarily infects CD4-positive T cells. In the course of an untreated HIV infection, their numbers can decrease significantly, thereby progressively weakening the immune system.