CD4-Positive T-Cells (Helper T Cells) (None)

CD4-positive T-cells, also known as helper T cells or CD4+ T lymphocytes, are a critical subset of white blood cells within the adaptive immune system. They express the surface glycoprotein CD4 and play a central role in orchestrating immune responses by activating and regulating other immune cells. These cells are essential for activating B cell antibody class switching, enhancing bactericidal activity of phagocytes, breaking cross-tolerance in dendritic cells, and supporting activation/growth of cytotoxic (killer) T-cells. CD4+ T-cell counts are used clinically to monitor diseases such as HIV/AIDS because HIV specifically infects and destroys these cells.

Other names

Helper T cellsCD4+ T lymphocytesTh cells

CD4+ T-cells orchestrate immune responses through cytokine secretion and cell-cell interactions, activating and regulating other immune cells like B cells, macrophages, and cytotoxic T cells. They recognize antigens presented on MHC class II molecules.