The Innate Immune System & Inflammation Flashcards
what is the innate immune system
rapid non specifc inflammatory response that responds to signals from the PRR
PAMPs
conserved molecular structures of bacteria, virus and pathogens that bind to PRR
Role of the innate immune system
controling infections during the first 7 days after an infection
How is the adaptive immune system activated
Most cells in the innate immune systen release cytokines or interact with each other directly in order to activate the adaptive immune system
Cells that are not antigen presenting
The delta gamma t cells and NK cells are not APC. They are considered innate cells with some similarities to effector lymphocytes
Functions of the innate immune system - 3
- Initial response to eliminate and control infections
- Recognise and eliminate dead and damaged cells
- Modulate the adaptive immune system to be more effective
The most important defense
mucous membrane and skin
how does the innate immune system differentiate between self and non self - 3
- Recognition of pathogen associated immunostimulants on the pathogen but absent on the host
- Stimulate inflammatory responses of phagocytosis by macrophages and neutrophils
- Microbes have some stuctures that are not seen on mammalian cells
Example of this difference - 7
- Prokaryotic translation initiation differs from eukaryotic
- Fmet in bacteria other than the normal fmet and is on the first AA
- Fmet on the N-terminus must be of bacterial origin
- Fmet serves as a chemosttractant for neutrophils which migrate quickly to the source
- Bacteria has shorter DNA sequences
- CpG motifconstist of unmethylated dinucleotide CpG flanked by two 5’ purines and two 3’ pyrimidines
- More common in bact DNA and it activates macrophages, stimulate inflammatory response and increase the production of antibodies by B cells
fMet is recognized as
as a PAMP, and can therefore be detected by PRR
what are PRR
proteins that are capable of recognizing molecules frequently associated with pathogens
what do PRRs recognize
PAMPs and DAMPs
Soluble PRR - 5
- Ficolin
- Collectin
- Pentraxin
- Natural antibodies (IgM)
- Complement proteins
Cell associated PRR
- TLR - plasma membrane
- NLR - cytoplasm
- CLR - cytoplasm
- RLR - plasma membrane
- Scavenger - plasma membrane
- N-formyl met-leu-phe - plasma membrane
two CLASSES of PRR
- endocytic/phagocytic - found on the surface of phagocytes and promote the attachment of microbes to the PRR for their engulfment and destruction
- signalling - binding of the microbial PAMPs to the PRR promotes infammatory cytokines, chemotatic factors, antimicrobial peptides, cytokines such as type 1 inteferons