pattern recognition receptors Flashcards
how are bacteria and fungi handled?
phagocytosis and killing
what is innate immunity?
present since birth, no requirement for memory (except evolutionary one)
how are viruses handled?
cellular shut-down, self-sacrifice, cellular resistance
describe adaptive immunological memory
is highly specific, cross-reacting or self-targeting
problems with immunity
Immunity can take a long time but infections arrive quickly and unpredictably
Only vertebrates have an adaptive system; there must be other effective immune systems
what are the two components of the PRR family?
1.Secreted and circulating PRRs
2.Cell-associated PRRs (more traditional receptors)
where are antimicrobial peptides secreted?
in lining fluids from epithelia
what are lectins and collectins?
carbohydrate-containing proteins that bind carbohydrates or lipids in microbe walls.
what do lectins and collectins do?
Activate complement, improve phagocytosis.
what are cell associated PRRs?
Receptors that are present on the cell membrane or in the cytosol of the cells
what do cell associated PRRs recognise?
Recognise a broad range of molecular patterns
what are the main family of cell associated PRRs?
TLRs are the main family (toll-like receptors)
what do pattern recognition receptors do?
recognition of microbes and viruses depends on seeing ancient, conserved features of them
what do families of pattern recognition receptors do?
detect these in fluids, cell surfaces and compartments, and intracellularly
what are the additional roles of pattern recognition receptors?
Additional roles in homeostasis and damage recognition
what are blood neutrophil numbers dependent on ?
upon TLR4 signalling, independent of LPS (lipopolysaccharide) in homeostasis
pattern recognition receptors- homeostasis?
Induction of endotoxin tolerance in the new born gut
Maturation of the normal immune system
what are TLRs adapted to do?
adapted to recognise a range of endogenous damage molecules, which may share characteristics of hydrophobicity
how does TLR signalling occur?
by cellular damage products activates immunity to initiate tissue repair and perhaps enhance local antimicrobial signalling
how do PRRs cause disease?- not sure about this q
Recognition of host molecules in autoimmune disease
Failure to recognise pathogens or increased inflammatory responses
