innate imunity

Cards (64)

  • dendritic cell
    antigen presenting to T cells
  • natural killer cell
    controls viral infection by killing tumour and virus infected cells
  • neutrophil
    mediate early inflammation
  • eosinophils
    parasite killing and contribute to asthma
  • mast cells
    release histamines that activates endothelium and increases blood vessel permeability
  • monocytes
    short lived source of resident macrophages and dendritic cells
  • macrophage
    phagocytosis, angiogenesis, synthesis of collagen rich ECM, and wound healing
  • angiogenesis
    new blood vessel growth
  • NK cells give immunity to viruses and cancer, and cause chronic inflammation
  • ILC1 offers immunity to intracellular bacteria and protazoa, and cause chronic inflammation
  • ILC2 offer immunity to helminths
  • ILC give immunity to extracellular bacteria and cause chronic inflammation
  • defensins
    form pores
  • lactoferrin
    binds and transports iron, which is anti bacterial and anti fungal
  • complement system is activated by recognition of pathogens
  • complement system results in enhancement of phagocytosis via opsonisation, inflammation, and lysis of microbes
  • C3b binds to microbe for phagocytosis
  • c3a binds to mast cells to release histamines
  • alternative pathway
    c3b binds to activating surfaces such as cell walls
  • classical pathway
    c1 binding to antigen-antibody complexes
  • lectin pathway
    binding of lectins in plasma to carbohydrates on microbes
  • c3a
    inflammation
  • c3b
    opsonisation and phagocytosis
  • c5a
    inflammation
  • c6-9
    lysis of microbe
  • c3b binds to antibody and becomes component of the enzyme that cleaves c5 and initiates the late steps of complement activation
  • c5b initiates late steps of complement activation, producing c5a
  • c5b forms a complex with c6-9 to form MAC
  • MAC
    makes pores in membrane to allow water and ion movement, resulting in lysis of microbe
  • macrophages dont circulate, trap antigen at site of infection, are derived from monocytes, and can produce cytokines
  • inflammatory macrophages live for days to weeks
  • tissue resident macrophages live for years
  • neutrophils increase during acute inflammation, and secrete lysosomal enzymes, first cells to migrate during inflammation
  • pus is mostly dead neutrophils
  • neutrophils are short lived, 1-2 days
  • phagocytosis steps
    chemotaxis, adherence, ingestion, digestion, killing
  • chemotaxis
    movement of phagocytes to site of damage due to chemical stimulus
  • adherence
    attachment of phagocyte to microbe
  • oxidative bursts generate oxygen radicals, and nitric oxide
  • opsonisation
    microbes targeted for destruction for phagocytes