IMM250H1 Lecture Notes - Lecture 4: Bacteroidetes, Microvillus, Clostridium
Document Summary
Skin and mucosal surfaces; portals of entry for microbes. Inhibit free entry of microbes into deep tissues. They do not have mucins thus they are directly exposed to particles in the gut lumen. Allows activation of lymphocytes to antigen or induction of tolerance to harmless entities. Found in peyer"s patch: part of gut associated lymphoid tissue and are especially involved in. Important for maintain homeostasis: uptake of non harmful antigen regulatory t cells that migrate from lamina propria to help maintain tolerance to food antigens and commensal bacteria. Prrs in gut: tlrs receptors are on surface while nod is intracellular, upon activation they activate transcription factor nfkappab production of pro-inflammatory cytokines & antimicrobial peptides recruit and activate inflammatory cells (neutrophils & macrophages) Beneficial effects of gi microbiota: synthesize essential metabolites i. e. vit k, breakdown diet fibers and produce scfas, completion for nutrients prevents colonization of pathogens, germ-free mice tend to consume more calories and weight less.
