early innate immune responses Flashcards
name some different types of tissue-resident innate immune cells
macrophages(WBC), dendritic cell and mast cells
what are the different functions of macrophages
phagocytosis, pro/anti inflammatory response, bacteria killing mechanisms, antigen presentation, wound healing/tissue repair
what are the different functions of mast cells
pro-inflammatory, parasitic killing mechanisms, linked to allergy and asthma
when is the innate immune response initiated
when the invading pathogens breach the physical barriers
what are the different modes of ingestion that macrophages use against bacteria and fungi
pinocytosis = ingestion of fluid surrounding cell
receptor-mediated endocytosis = molecules bound to membrane receptors of pathogen are ingested
phagocytosis = pathogen ingested whole
what facilitates the ingestion of foreign bodies by macrophages
opsonisation, which = coating of pathogens by soluble factors(opsonins) to enhance phagocytosis
briefly describe process of phagocytosis by a macrophage cell
macrophages express set of PRRs, these bind to PAMPs signals and form phagocytic cup, cup extends round pathogen and cuts it off, forms phagosome, fusion with lysosomes forms phagosome and kills pathogen and degrades content, debris is released, pathogen peptides are presented on surface
what is meant by the terms PAMP and PRR
PAMP = pathogen-antigen molecular patterns PRR = pattern recognition receptor
in what ways do mast cells help in early innate immune response
degranulation = release of pre-formed pro-inflammatory substances
gene expression = production of new pro-inflammatory substances
how do macrophages stimulate the acute immune response
by production of pro-inflammatory mediators
pro-inflammatory mediators = nitric oxide, histamines, pro-inflammatory cytokines, leukotrines
