Medicine & USMLE


  1. TNF-alpha
  2. IL-1
  3. IL-2
  4. IL-3
  5. IL-4
  6. IL-5
  7. IL-6
  8. IL-8
  9. IL-10
  10. IL-12
  11. TGF-beta
  12. IFN-alpha and IFN-beta
  13. IFN-gamma


Interleukin-12 (IL-12) is a cytokine produced by macrophages. IL-12 activates both Th1 and Natural Killer (NK) cells, which both help in the immune response against intracellular pathogens (like viruses).

Key Points

  • Interleukin-12 (IL-12)
    • Secreted by Macrophages
    • Promotes defense against intracellular pathogens
      • Promotes differentiation of Th1 cells
        • Helper T-cell subset that coordinates immune response against intracellular threats
      • Activates Natural Killer (NK) cells
        • Directly kills virally-infected cells or other cells that suppress MHC expression