Summary

T-cells, also known as T-lymphocytes, are a class of white blood cells that operate in our adaptive immune response. T-cells act by direct contact to either kill infected cells or by coordinating an immune response with other immune cells. T-cells directly bind to antigens presented on MHC, and when the antigen is abnormal, the T-cell will either act to directly kill the cell or coordinate a concerted immune response against the threat. Notably, because the T-cell works directly via contact, this response is known as the cell-mediated immune response.

Key Points

• T-Lymphocytes (T Cell) Overview 
  • Part of adaptive immune system
    • Directly work to kill infected cells (cell-mediated)
  • Activated by binding a specific antigen
    • T-cell Receptors (TCRs) bind to antigens presented on MHC I or II 
    • TCRs undergo rearrangement of genes to allow for greater binding diversity
  • Differentiate after activation into either cytotoxic, helper, or memory T-cells