Double-positive CD4-positive CD8-positive T lymphocyte (DP T cell)

Double-positive CD4-positive CD8-positive T lymphocytes (DP T cells) are a minor peripheral blood T cell subset (typically ~1–2% of circulating T lymphocytes in humans) that co-express both the CD4 and CD8 co-receptors[1][2][4]. This population is distinct from the transient CD4/CD8 double-positive thymocytes that are developmental intermediates; mature peripheral DP T cells are found in healthy individuals and can expand in various disease states such as infections, cancer, and autoimmunity[2][4]. Peripheral DP T cells typically display functional characteristics associated with memory T cells, including the expression of chemokine receptors and activation markers, production of multiple cytokines (e.g., IFN-γ, IL-2, TNF-α, IL-4, IL-17A), and cytolytic enzymes (perforin, granzyme B)[1]. Their precise immunologic function remains under investigation, but evidence suggests roles in enhanced immune surveillance, immunoregulation, and potentially both antitumor and protumor activities depending on context[4]. They are not regarded as a therapeutic "target" in the conventional sense of a molecule/receptor for drugs but as a subset of immune cells whose presence and phenotype may serve as a biomarker for certain disease states or immune responses[1][2][4]. Key issues: - This entity is a *cellular subset*, not a single molecule, receptor, enzyme, or standard drug target. - Therapeutic targeting is not established for this population specifically, making it an informative biomarker or research focus but not a canonical drug target. Accordingly, the query appears to conflate multiple entities ("CD4-positive and CD8-positive T lymphocytes"), making it an incorrect or noncanonical entry for a "target" in drug development/biological databases.

Other names

Double-positive T cellCD4+CD8+ T lymphocyteCD4+CD8+ DP T cellDP T cell

Not a drug target; mechanisms are general T-cell receptor mediated signaling, cytokine-driven activation