Basic Immunology Principles

Basic Immunology Principles

1. Innate/Nonspecific Immune System

   • Born with it
   • First line of defense
   • Physical barriers such as skin
   • Chemical barriers and components in nasopharynx, guts, GI tract, and lungs
   • Inflammatory Responses
   • Monocytes (blood) will follow neutrophils to inflammatory sites
   • Macrophages from connective tissue, liver, lung, brain, spleen, bone marrow, and lymph nodes will ingest and destroy invaders within tissues
   • Natural Killer Cells or NK are a small subset of lymphocytes within lymph organs and blood that recognizes and destroys host cells infected with microbes or viruses. Activates phagocytes by interferon-y
   • Interferons are cytokines that ellicit cellular reactions that prevent viral replication
   • Complement Cascade is a group of proteins in the blood that consist of chemical reactions that consist of three pathways

2. Adaptive/Specific/Acquired Immune System

   • Humoral Component
     • B Lymphocytes
       • Produces immunoglobulins
         • Y shaped Molecules: igG, IgM, IgE, IgA, IgD
       • Secreted in body fluid or "humors"
       • Each time an antigen enters the body, the B cell reacts
       • Specific receptor to a specific antigen
       • Matures in the bone marrow
   • Cell-mediated Component
     • T Lymphocytes
       • Matures in the thymus
       • Specific receptor to specific antigen
       • Helper T Cells
         • Recognizes phagocytized antigens swallowed by antigen-presenting cell (APC) by releasing cytokines to further phagocytize ingested invaders
         • Helps B cells differentiate into anti-body producing cells
   • Reponds specifically to foreign substances