Innate Immunity

• Natural Killer (NK) Cells [from lymphoid lineage]

  • Function: Contact every cell in the body; If not MHC Class I --> NK kill
  • Increase NK in peripheral blood
  • Decrease target binding and killing per cell (Decrease ability to identify MHC Class I)
• Polymorphonuclear (PMN) Cells [Neutrophil]

  • Decrease entry into wounds
  • Decrease phagocytosis, ROS production, intracellular killing of bacteria
• Monocytes/ Macrophages

  • Decrease cytokine production
  • Decrease ROS production; Impaired tumoricidal activity
• Thymus decrease in size (shrink) with age