n :  any of several lymphocytes (as a helper T cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (as by the regulation of T and B cell maturation and proliferation) and others that lyse antigen-bearing cells - called also T lymphocyte  - see HELPER T CELL KILLER T CELL SUPPRESSOR T CELL T4 CELL  .
 
 
 
Similar sounding terms:  tes·la  T4 cell  tus·sal 
 
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