The C allele is protective of HCV in TLR3, TLR7 (rs3853839) in females only, and TLR8 (rs3764879) in males only, while risk of infection is linked to the T allele in TLR7 (rs179008) in females only and the A allele in TLR8 (rs3764880) in both sexes.
Our results suggest that variations in TLR7 and TLR8 genes modulate the clearance and progression of HCV infection with different magnitudes between sexes.
Furthermore, knockdown of TLR8 completely attenuated collagen expression in monocytes exposed to HCV, and knockdown of TLR7 partially attenuated this expression, suggesting roles for TLR7/8 in induction of fibrocytes in HCV infection.
Our previous study demonstrated that the TLR8-129G>C (rs3764879) and TLR8+1G>A (rs3764880) variants were in complete linkage disequilibrium, and that the frequency of TLR8-129C/+1A was significantly higher in male patients with HCV infection compared with the healthy controls.
Stimulation of normal monocytes with TLR4 and TLR8 ligands or HCV core, NS3 and NS5 recombinant proteins induced a robust increase in both miR-155 expression and TNFα production identifying potential mechanisms for in vivo induction of miR-155.