T helper cell (CD4-positive T lymphocyte) (CD4+ T cell)

CD4-positive T lymphocytes, also called T helper cells, are a major subset of T cells characterized by expression of the CD4 surface molecule. They orchestrate and modulate adaptive immune responses by recognizing antigens presented by MHC class II molecules on antigen-presenting cells. Upon activation, these cells differentiate into multiple effector subsets (e.g., Th1, Th2, Th17, Treg) that direct diverse immune functions mainly via cytokine secretion. Modulation of their responses—through intrinsic or extrinsic signals—plays a central role in immunity against pathogens, tumor immunity, autoimmunity, and inflammatory diseases. While they are a primary target for immunomodulatory therapies, "CD4+ T lymphocyte response modulation" is not itself a molecular target, but encompasses various pathways and receptors involved in controlling CD4+ T cell activity.

Other names

Helper T cellT helper lymphocyteCD4-positive T lymphocyte

Cytokine modulation: Drugs like IL-2 act through receptor-mediated stimulation, expanding or activating CD4+ T lymphocytes.\nImmune checkpoint inhibition: Antibodies block inhibitory pathways, enhancing CD4+ T cell activation.\nImmunosuppression: Agents like cyclosporine or steroids inhibit signaling pathways required for CD4+ T cell function.