BIOL 2312 Lecture Notes - Lecture 51: Lectin, Human Microbiota, Signal Transduction
Document Summary
Innate immunity: - also leads to inflammatory response and complement response. Brings cells to site of infection and uses soluble anti-microbial proteins to fight pathogens. Complement system: also ancient, found in horseshoe crab. Genetic rearrangements create molecules capable of recognizing pathogens. Defends body: impenetrable barrier, chemical weapons on surface. Home to normal flora (non-pathogenic bacteria/fungi) invading pathogens must compete with them. Epidermis is 10-30 cells thick; cells shed + replace continuously. Innate response based on recognition of molecules characteristic of a type of pathogen. Examples: lipopolysaccharide in gram-negative, peptidoglycan in bacterial cell walls, viral dna and rna: toll-like receptors: Toll receptor in drosophila and toll-like receptors (tlr): best studied (found in dorsal-ventral patterning pathway. Unmethylated cpg motifs in bacterial dna, and viral rna. Tlr contain leucine-rich regions fold to form binding pockets (can accommodate many shapes) In different tlrs pockets recognize different classes of pathogen. Tlr bind to targets important for pathogen survival.
