MOLECULES OF INNATE IMMUNITY Flashcards
list the molecules of innate immunity.
- pattern recognition receptor (PRR)
- pathogen associated molecular patterns (PAMPS)
- cytokines
what is PRR?
an immune system receptor that recognize non-self foreign substances
what does the PRR identify and do?
it identifiey molecules associated with foreign substances and enable immune cells to differentiate between self and non-self.
they(PRR) are mainly expressed in _____but they are also found in______.
- antigen presenting cell (APC) such as macrophages, dendritic cells and B cells.
- other immune (neutrophil, mast cell, NK cell) and non-immune cells (eputhelial cells).
what are the groups that PRR are divided into?
- Toll-like receptors (TLR)
- neuclotide oligomerisation receptors (NLR)
- C-type lectin receptors (CLR)
- RIG-1 like receptors (RLR)
where does PRR present?
- at cell surface to recognize extracellular pathogens like bacteria and fungi
- in the endosomes where they sense intracellular invaders like viruses
- in the cytoplasm
how does PRR recognize pathogen?
PRR recognize particular overall molecular patterns of the pathogen that are generally absent from the host
list down which group present on which part
cell surface - TLR and CLR
endosomes - TLR
cytoplasm - NLR and RLR
what is PAMPS?
The pattern found on pathogens are called pathogen-associated molecular patterns (PAMPs)
TLR-1
TLR-2
TLR-3
TLR-4
TLR-5
- lipoproteins
- bacterial lipoproteins
- dbl-stranded RNA
- lipopolysaccharide, some viral proteins
- flagellar protein
what are the characteristics of PAMP
- incl combination of sugars, certain proteins, particular lipid-bearing molecules and some nucleic acid motifs
- shared by groups of related microbes
- structures are relativley invariant; do not evolve rapidly
- molecules are essential for the survival of the organisms
- unique molecules displayed on stressed, injured, infected, or
transformed human cells also act as PAMPs. - unique microbial structural patterns of motifs that are not shared with their host.
TLR and its ligal bond
some TLR and the non-self components they bind
what is cytokines?
low molecular weight proteins secreted by cells of both innate and adaptive immune system and can regulate diverse functions in the immune response
TLR-6
TLR-7
TLR-8
TLR-9
TLR-10
- lipotechoic aciud
- single-stranded viral RNA
- single-stranded viral RNA
- bacterial DNA
- unkown
what is the role of cytokines?
communication within the immune system and in allowing the immune system and host tissue celss to exchange infos
which cells they attack?
they affect whatever cells they encounter that bear appropriate receptors and are in a physiological state that allows them to respond
how does cytokines act?
in an antigen-nonspecific manner
what are the two major families in cytokines?
- hematopoietin family - growth hormones and interleukins(ILs)
- tumor necrosis factor (TNF) family
when TLRs recognize a pathogen,______.
a variety of cytokines are
released, chiefly from the TNF family.
what are cytokines mode of action?
- autocrine action
- paracrine action
- endocrine action
explain autocrine.
cytokines bind to receptors
on the membrane of the same cell that secreted
it (affect the cells that produce them).
explain paracrine.
cytokines bind to receptors on a target cell in close proximity to the producer cell (cytokines affect the neighboring cells).
explain endocrine.
cytokines bind to target cells in distant parts of the body (cytokines affect cells in other areas of the body).
what does the action of cytokine depend on?
its concentration
