Innate Immunity 2 Flashcards
Mast cells, basophils, eosinophils
polymorphonuclear granulocytes
cytoplasmic granules containing
antimicrobial
antiparasitic
vasoactive
inflammatory mediators
destruction of pathogens by degranulation
What is degranulation of cytoplasmic granules elicited by?
microbial antigens (PAMP)
antibody
complement fragments
Mast cells
resident in tissue; adjacent to small blood vessels and nerves
concentrated in internal and external surfaces
Basophils
<1% of blood leukocytes
recruited from blood during inflammation
Eosinophils
~3% of blood leukocytes
especially important in the defense against worms
recruited from blood during inflammation
Mediators produced by mast cells, basophils, eosinophils
Granule content
enzymes
eosinophil cationic protein
histamine
prostaglandins
leukotrines
platelet-activating factor
cytokines
Functions
antimicrobial/antiparasitic
vascular permeability
smooth muscle tone
blood clotting: leukocyte
recruitment and activation
Natural Killer cells activation mechanism
blood, liver, spleen, uterus
unique activation mechanism:
natural inhibitory receptors for healthy cells
natural activating receptors for infected/damaged cells
Activation determined by balance of inhibitory and activating receptor stimulation
What are the functions of natural killer cells?
- Cytotoxic activity mediated by perforin & granzyme
defense against viral infections and tumours - Release of the cytokine interferon-y by NKCs enhances ability of macrophages to kill phagocytosed microbes
classical activation
Dendritic cells
long, membranous projections
concentrated in external and internal surfaces
phagocytic cells, to break it up and present it to other eells in order to activate them
Professional antigen presenting cell
Dendritic cells: professional antigen presenting cell
Link between innate and adaptive immunity
Phagocytose microbes
Migrate to lymph nodes
Present antigen to lymphocytes
Lymphocyte proliferation & differentiation
