L9 - Phagocytosis and Cytokines Flashcards
functions of phagocytes
- recognize
- contain
- destroy
methods by which phagocytes recognize pathogens
pattern recognition, complement, Fc receptors
Toll-like receptor (TLR)
recognize LPS via association with CD14; expressed in both endosomes and on cell surface
NOD-like receptors (NLRs)
cytoplasmic receptors that recognize peptidoglycan layer of bacteria
RIG-I-like receptors (RLRs)
recognize viral nucleic acids and induce interferon I production
types of phagocytes
neutrophils, monocytes/macrophages, dendritic cells
phagocyte recruitment and activation
- attachment - leukocytes “roll” along endothelium due to interactions between sialyl-Lewis on leukocytes and E/P selectins on endothelium
- activation - activating signals increase lymphocytic expression of integrins, which bind to ICAMs on endothelium
- diapedesis
- migration - chemokines (IL-8) lead the leukocyte to the site of infection
IL-1
key mediator of initiating fever
IL-6
cytokine that activates acute phase response
IL-8
cytokine that serves as a chemotactic factor to guide lymphocytes to site of infection
IL-12
cytokine that activates NK cells; promotes differentiation of CD4 T cells into TH1 cells
recognize LPS via association with CD14; expressed in both endosomes and on cell surface
Toll-like receptor (TLR)
cytoplasmic receptors that recognize peptidoglycan layer of bacteria
NOD-like receptors (NLRs)
recognize viral nucleic acids and induce interferon I production
RIG-I-like receptors (RLRs)
key mediator of initiating fever
IL-1
