Abstract
Recent advances in immunology have challenged the conventional division of T-lymphocyte function by uncovering novel subpopulations with diverse roles and characteristics. This article reviews these discoveries and their implications for understanding immune regulation and disease pathogenesis. Innovative techniques have enabled the identification of previously unrecognized T-lymphocyte subsets, disrupting the classical classification system. Helper lymphocytes, including T(fh1), T(fh2), T(fh17), GC-T(fh), and circulating T(fh) cells, exhibit distinct functions in immune responses and disease states. Additionally, newly identified cytotoxic T-cell subsets, such as CD8(+)CD39(+) and CD8(+)CD28(+) cells, demonstrate unique effector properties with potential therapeutic applications in cancer immunothe- rapy. Furthermore, the discovery of CD20(+) T cells challenges traditional views, offering new avenues for immunotherapy in cancer, autoimmune disorders, and infectious diseases. These findings expand our understanding of T-lymphocyte biology and suggest targets for more effective therapeutic interventions. Further research is essential to fully elucidate the clinical relevance and therapeutic potential of these T-lymphocyte subpopulations, paving the way for personalized and targeted immune-based treatments.