Cell-Mediated Immunity

Artificially Acquired Immunity

• Effective against antigens in cells and tissues
• Effective against bacteria, viruses, fungi, and protozoa
• Uses different types of T cells
• Helper T cells (TH):
• Activate macrophages
• Help form B cells
• Promote production of Tc
• Cytotoxic T cells (Tc/ Killer): precursor to cytotoxic T lymphocytes (CTL)
• Cytotoxic T lymphocytes (CTL/ Killer): destroys antigen on contact
• Regulatory T cells (Tr/ Suppressor): turn off immune system response when antigen is gone

• Active:
• Injection of antigens using vaccines which cause the production of antibodies
• Vaccine or immunization: process of introducing killed, live, or inactivated pathogen
• Passive: injection of antibodies from another person or animal

Types of Adaptive Immunity

• Naturally Acquired Immunity
• Active:
• Natural exposure to antigens causes production of antibodies
• Can be lifelong immunity
• Ex. Mononucleosis
• Passive:
• Transfer of antibodies from mother to child
• Ex. Breast milk or placenta

Cell-Mediated Immunity