The Effect Of The S130P Mutant Epitope Peptide In Hepatitis B Virus Core Protein On The Expression Of TLR2?PD-1?IL-10 And IL-18 In Monocyte/macrophage

Background:Hepatitis B is an infectious disease caused by hepatitis B virus.It is an important reason of acute and chronic hepatitis.There are about 248 million individuals chronically infected with HBV worldwide,and about 686 thousand people died of various liver diseases because of HBV infection each year.With the prevalence of hepatitis B vaccine,HBsAg seroprevalence is less than 1%in children 1-4 years old in our country.But the mechanism of HBV persistence is still unclear.Previous studies have shown that HBV does not have direct cytotoxicity to cells,the immune response is the main cause of the disease.Monocyte/macrophage is not only the main components of the innate immune system,but also plays a major role in the initiation and maintenance of adaptive immune response.It has been reported that the function of monocytes in patients with chronic hepatitis B is damaged,the innate immune defense barrier is hindered,which affects the clearance of the virus.Moreover,the dysfunction of virus specific T cells plays a significant role in the pathogenesis of HBV.And the effect of macrophages on the function of T cells is one of the important reasons for the depletion of T cells.Hepatic macrophages can be activated by hepatitis B core protein and produced more TLR2,further promoting the secretion of IL-10,drives CD8~+T cell exhaustion,resulting in immune tolerance.Studies of patients infected with HCV or HIV show that expression of PD-1 on monocyte/macrophages is higher than that of healthy control,and its increase affects the antiviral activity of the body.An article published on Gut in 2000 found that Kupffer cells from HCV-infected subjects exhibit increased IL-18 and IFN-?expression,which mediated Th1 cell immune response and promoted liver inflammation and liver injury.Our previous studies found that the hepatitis B virus core protein S130P epitope peptide influences IFN-?secreted by CD8+T cells,and patients with genetic mutations are more prone to seroconversion of e antigen.Further,monocytes and macrophages affect the function of T cells in many ways.Therefore,we speculate that the mutant epitope peptide S130P may affect the immune function of macrophages and further regulate the immune activity of T cells,thus influencing the adaptive immune response.Thus,we detected the expression of TLR2,PD-1,IL-10 and IL-18 on THP-1 derived macrophages,human peripheral blood mononuclear cells and macrophages derived from monocytes,by HBc S130P mutant stimulation,further understanding the mechanism of chronic hepatitis B,provides a new approach of antiviral therapy.Aims:THP-1 derived macrophages,human peripheral blood mononuclear cells and macrophages derived from peripheral blood monocytes were stimulated with hepatitis B virus core protein S130P epitope peptide,and the expression of TLR2,PD-1,IL-10 and IL-18 in these cells were detected by flow cytometry and real-time quantitative PCR,to explore their role in the pathogenesis of chronic hepatitis B.Methods:1.THP-1 derived macrophages were stimulated with or without S130P epitope peptide,and the expression of TLR2,PD-1,IL-10 and IL-18 were detected by flow cytometry and real-time quantitative PCR;2.Fifteen patients with CHB,twenty asymptomatic carriers and ten healthy control were enrolled,general information and related clinical data were collected.PBMC were isolated from the whole blood and stimulated by S130P epitope peptide,then analyses the expression of TLR2,PD-1,IL-10 and IL-18 in monocytes.In addition,monocytes isolated from PBMC were differentiated into macrophages by M-CSF,investigates the expression of TLR2,PD-1,IL-10 and IL-18 in macrophages after the stimulation of peptide.Results:1.The hepatitis B virus core protein S130P epitope peptide enhances the expression of TLR2,PD-1,IL-10 and IL-18 in THP-1 derived macrophages;2.Monocytes of asymptomatic carriers and patients with CHB produce more TLR2,PD-1,IL-10 and IL-18 with the stimulation of peptide.But only TLR2 increases in healthy controls.On the other hand,the expression of TLR2,PD-1 and IL-10 increases in monocytes derived macrophages,but IL-18 doesn't change significantly.Conclusion:Hepatitis B virus core protein S130P epitope peptide influences the expression of TLR2,PD-1,IL-10 and IL-18 in monocyte/macrophage,suggesting that HBV may affect the TLR signal transduction pathway and the secretion of cytokines through the interaction with monocyte/macrophage,and regulate the immune response,thus affecting the course of the disease.