Question

How toll like receptor trigger adaptive and innate immune system

Answer 1

Toll like receptors(TLRs) are a class of pattern recognition receptors that function as signalling receptors.

Each TLRs is composed of an extracellular N-terminal domain and an intracellular C-terminal region.

All TLRs are synthesized in the endoplasmic recticulm,traff to the Golgi,and are recruited to intracellular compartment such as endosomes.

TLRs have also been shown to be an important link between innate/adaptive immune system through their persence in dendritic cells.

Adaptive immune system--TLRs expressed on the membranes of leukocytes including dendritic cells,cells of the adaptive immunity.

Binding of the ligand form of adjuvant used in vaccinations.

If the ligand is a bacterial factor the pathogen might be phagocytosed and digested,and its antigens presented to CD4+T cells.

In the case of viral factor the infected cells may shut off ,it's protein synthesis and may be undergo apoptosis.

Innate Immune system---TLRs play a key role in the innate Immune system.

They are single mambrane spanning, non catalytic receptors.

Once these microbes have reached physical barriers such as the skin or intestinal tract mucosa, recognized by TLRs,which activates immune cell response.

TLRs signalling--consist of two pathway first is myD88 (myeloid differentiation factors) dependent pathway that leads to the production of inflammatory cytokinesis,and signalling induced by all TLRs.

Second is myD88 independent pathway associated with the stimulation of IFN-beta and characterizes by TLR3 and TLRs 4.