An overview on T - cells and regulatory cells

T - cells play a central role in adaptive immunity by recognizing specific antigens and coordinating immune responses. They originate from hematopoietic stem cells in the bone marrow and mature in the thymus, differentiating into distinct subsets such as hel per T - cells (CD4⁺), cytotoxic T - cells (CD8⁺), and memory T - cells. Among these, regulatory T - cells (Tregs) are a specialized subpopulation essential for maintaining immune tolerance and preventing autoimmune disorders. Tregs, primarily characterized by the expression of CD4, CD25, and the transcription factor FoxP3, suppress excessive immune activation and maintain immune homeostasis. Dysfunction or imbalance of T - cells and regulatory cells is associated with various pathological conditions, including autoim mune diseases, chronic inflammation, cancer, and transplant rejection. Recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive T - cell therapies, highlight the clinical significance of understanding T - cell biology and regulator y mechanisms. This review provides an overview of T - cell development, classification, functions, and the crucial role of regulatory T - cells in immune modulation and disease management .