cells of the innate immune system Flashcards
what is usually the fist cell to arrive at the site of infection?
neutrophil
what are neutrophils?
most abundant circulating white blood cell
large, granular cells with multi lobed nuclei
what is the major function of neutrophils?
to phagocytose microbes
release granules containing antimicrobial substances
what do monocytes mature into?
macrophages
when do monocytes mature?
when they enter inflamed or infected tissue
how are subsets of monocytes distinguished?
by cell surface markers
what is the main subset of monocytes in humans and what cell surface markers do they posses?
classical / inflammatory
CD14
what are non classical monocytes thought to aid in? what cell surface markers do they express?
tissue repair
CD16 and CX3CR1
what do macrophages release and what is the purpose?
cytokines which recruit other immune cells
what is the function of macrophages?
highly phagocytic
can present antigens
activate T and B cells
what is the function of resident macrophages?
surveillance duties
can have organ specific functions
what are dendritic cells?
phagocytic cells that activate lymphocytes
the bridge between innate and adaptive immune systems
when are dendritic cells immature and when do they mature?
immature when in tissues
mature as they migrate to the lymph nodes
what function are dendritic cells highly specialised to perform?
antigen presentation to T and B cells
what is the function of eosinophils?
surround very large pathogens and cause damage by secreting extracellular granules
what is the function of basophils?
secrete extracellular granules
promotion of allergic responses
augmentation of anti parasitic immunity
what is the function of mast cells?
release granules containing histamine and active agents
have a pro inflammatory effect to prevent parasites on mucosal surfaces
what is the function of natural killer cells?
kill infected host cells
important for anti-viral and anti-cancer immunity
what do natural killer cells secrete and what transcription factor do they express?
secrete IFN gamma
express T-bet
what do type two innate lymphoid cells secrete and what transcription factor do they express?
secrete IL-5 / 13
express GATA-3
what is the function of type 2 innate lymphoid cells?
protect against parasitic worms
roles described in asthma and immunity to pulmonary pathogens
what do type 3 innate lymphoid cells secrete and what transcription factor do they express?
secrete IL17 / 22
express ROR gamma T
what are lymphoid-tissue inducer cells needed for? and which type of ILC are they a part of?
development of lymph nodes during embryogenesis
type 3 ILC
