Microbiology and Immunology 2500A/B Lecture Notes - Lecture 2: Innate Immune System, Gastrointestinal Tract, Respiratory Tract
21 Mar 2020
School
Department
Professor
Document Summary
Innate immunity: first line of defense against pathogens. Effective at stopping majority at early stages. Deficiencies in innate defense rare: barriers: block pathogen entry into tissues, innate cells: rapidly eliminate pathogens that enter tissues. If innate immunity unsuccessful: certain innate cells trigger adaptive immunity (takes around ~2 weeks) Born w/ innate immune defenses (ie. barriers, cells) Share the same immunity w/ plants & invertebrates. Everyone"s innate immunity responds to pathogens same way. Plants don"t have adaptive but invertebrates do. Discovered innate receptors by studying other organisms (ie. fruit flies) Most pathogens enter through respiratory and gi tract. Epithelial cells line all entry points; forms physical barrier. Cilia: hair-like structures that rhythmically beat to push pathogens out (ie. during coughing) Goblet cells: secrete mucin (mucin + water = mucous) Form tight junctions through active binding (ie. no gaps) Leaky gut syndrome: dysfunction of intestinal epithelial cell tight junctions. Secrete antimicrobial peptides that kill pathogens ( -defensins)
