Question

28.Provide an example for each group of PRRs listed below. Include a description in 1- 2 sentences of what the PRR recognizes, and how that recognition activates the innate immune response: a) Free receptors in the serum b) Membrane-bound phagocytic receptors c) Membrane-bound signaling receptors d) Cytosolic signaling receptors

Answer 1

A. Free receptors in the serum : These are also known as secretory proteins which helpful in binding with PAMPs and activate cascade which helps later in initiation of phagocytic process .some examples are c reactive protein ,complement receptors etc..

B. Membrane bound phagocytic receptors :These are the PRR receptors present on the phagocytic cell .Toll like receptors is one of the receptors which binds to PAMPs which helps in intracellular signalls to activate and undergoes killing process.

C. One of the example of membrane bound signalling receptors are Toll like receptors.

toll like receptors are the proteins which are usually present in macrophages and dentritic cells.Which is a homodimer interacts with the Pathogen associated molecular pattern and which activates or triggers the MAP Kinase signalling pathway later which leads to the production of the cytokines which is helpful for generating innate immune response.some of the cytokines are IL-1 and TNF- beta.

D. Cytosolic signalling receptors are Node like signalling receptors

These are ligands which recognises the peptidoglycan in the bacteria which leads to the activation of the signalling pathway which causes releases of cytokines .It is activated mainly in the absence of toll like receptors.Some of the ligands are NOD1 and NOD2 .Another example i sRIG-1 like receptor