Th1 lymphocytes are critical in the cellular immune response and they play an important role in host defense systems for intracellular microbial agents and viruses. Th1 cell promoting factors include IFNγ, IL-12 (p70), and the activation of the transcription factors STAT1 and STAT4. The expression of the Interleukin-12 receptor β2-chain (IL-12Rβ2) is required for Th1 cellular differentiation since it allows for the responsiveness to IL-12 on the Th1 cells. IL-12R activation increases IFNγ expression through STAT1 signals to induce the Th1 master regulator T-bet. This further increases IFNγ expression while suppressing IL-4. 

Relevant Recombinant Proteins

  • IL-2
    • Expressed by activated T cells, but not by resting T cells
    • Mediates proliferation of activated T cells
  • IL-12 p70
    • Produced by activated macrophages
    • Promotes survival and growth of Th1 cells
    • Sustains sufficient number of memory/effector Th1 cells
    • Inhibits the formation of Th2 cells
  • IL-27
    • o Produced by activated monocytes, macrophages, and dendritic cells
    • o Synergizes with IL-12 to cause the production of IFNγ by naïve Th cells
    • Increases proliferation of cells without affecting memory T-cells
  • IFN-gamma
    • o Autocrine factor in the establishment of Th1 cells
    • o Enhanced by the action of IL-12

Relevant Neutralizing Antibodies

  • Anti IL-4
    • o Prevents Inhibition Th1 differentiation and promotion Th2 differentiation
    • Mediates proliferation of activated T cells