Immunology: Sentinel cells and Early defence Flashcards
What are PAMPs?
Pattern recognition patterns: recognise molecules in pathogens
What are DAMPs?
Damage associated molecular patterns: self proteins which are seen when cells are damaged
What are the cells in innate immunity?
Neutrophils, macrophages, dendritic cells, NK cells
What do neutrophils do?
Phagocytosis, ROS and nitrogen species, antimicrobial peptides
What do macrophages do?
Phagocytosis, inflammatory mediators, antigen presentation, ROS and NS, cytokines, complement proteins
What do dendritic cells?
Antigen presentation, costimulatory signals, ROS, interferon, cytokines
What do NK cells?
Lysis of viral-infected cells, interferons, macrophage activation
Explain tissue resident macrophage
Phagocytose from their environment
Explain macrophages and infection
Exist in three states: resting, activated, hyperactivated
Explain resting macrophage
Ingest normal cell debris
Express few MHC II
Explain activated macrophage
Increase phagocytosis
Up-regulate MHC II expression
Explain hyperactivated macrophage
Stop proliferating, increase phago
Secrete cytokines
Increase lysozyme
Explain neutrophils
Display PRR (e.g. Toll like receptors TRLs)
Cytokines that activate other cells
Phagocytes
Explain dendritic cells
Generate ROS and nitric oxide and antimicrobial peptides
PRR (TLRs)
Increase MHC II
What happens when DC maturation?
Reduce phagocytosis, migrate on activation, present to T cells
What do NK cells do and what are they?
Large, granular cytotoxic lymphocytes
Destroy tumour cells,
What happens when NK cells are activated?
Become more effective at killing and produces more cytokines
Explain mast cells
Contain cytoplasmic granules that contain histamine
Recruit cells to inflammation
Explain eosinophils
Kills parasites
Have granules that create hole in parasite membrane
Explain complement system
Directly attacks pathogens
Hole punched in pathogen
What are the three types of complement system pathways?
Alternative, lectin, and classical
