IMM250H1 Lecture Notes - Lecture 2: Goblet Cell, Tight Junction, Defensin
Document Summary
Innate and adaptive immunity work together to clear infections. Innate host defenses against infections plan a: physical constitutive barriers, if unsuccessful plan b: innate response (destroy invaders) Types of barrier defense that exist prior to pathogen entry: mechanical, chemical and biological first line defense strategies . Pathogen cannot enter host until they pass these initial barriers. Innate barriers defense strategies once pathogen enters body: lysosome found in secretions in tears dissolve cell walls, mucus/cilia lining in trachea move microorganism out of body, stomach acidity (ph. 2) prevents microbial growth: flora in gut compete with pathogen. Enzyme that breaks cell wall of bacteria by attacking bond that keeps peptidoglycan together. Bacterial cell membrane is exposed to antimicrobial agents. Have positive and negative region + region binds to negative charged membrane of microbe and forms a pore that destroy the cell of membranes of pathogen. Form tight junctions between cells block entry of microorganisms. Goblet cells produce mucins which form mucus layer.
