01 Innate Immunity

Innate vs adaptive

  • Innate immune response can react directly to invaders
  • T cells require antigen presentation from APC
  • If T cells can react to any thing, then autoimmune problems

Cytokines

  • interleukins: travel between leukocytes

CD

Innate

  • Neutrophils on call to assist macrophages when needed

  • Virus have double stranded RNA and some single stranded RNA that transiently gets copied to double
  • DNA in human is methylated; bacteria has unmethylated DNA

Macrophages

  • macrophages guards, ready to consume any foreigners

Phagocytosis

  • proteases break down proteins, nucleases nucleotides, lysozymes cell wall

  • tissue destruction from macrophages/neutrophils

  • TB modifies surface of phagosome

Cytokines

  • macrophages 1st line of defense: IL-1

  • macrophages 1st line of defense: 1st IL
  • IL1 raises set point temperature
  • TNF-a kills tumors by causing coagulation in tumors, but can also cause DIC

Neutrophils

  • backup cells to macrophages

  • SL X: carbohydrate

  • Neutrophils always have SL X, normally nothing to bind to

  • ICAM always on endothelial cells, normally can't bind anything

  • alk phos: low in some leukemias (CML)
  • collagenase: breaks down collagen; lysozyme: breaks down cell wall; lactoferrin: found in breast milk and binds iron, lyse bacteria and kill cell in neutrophils

  • LTB4

Complement

  • alternative pathway: spontaneous conversion

NK cells

ADCC

  • antibodies elements of adaptive immune system

  • NK part of innate; T/B part of adaptive

Eosinophils

  • positive charge picks up Eosin dye

Basophils

  • helminths binds multiple IgE, triggering cross link and degranulation

Dendritic Cells

  • star shaped
  • professional antigen presenters
  • battle raging in tissue; dendritic cells pick up antigen to present to T cells