Effect Of Alcohol On Intrahepatic Humoral Immunity And Clearance Of HBV Infection

BackgroundAlcohol has gained popularity all around the world.The amount and frequency of alcohol consumption in traditional western countries are much higher than those in other countries and regions.Research shows that the trend of alcohol consumption in Western countries has been leveling off in recent years.However,Asian countries have seen a significant surge in alcohol consumption.As the third leading cause of diseases worldwide,alcohol is also a causal factor in more than 60 diseases and injuries.In recent years,studies have shown that alcohol can act as a protective factor for rheumatoid arthritis due to its immunosuppressive effect.Alcohol can weaken the promotion of humoral immunity by weakening the function of follicular helper(Tfh cells)T cells.In recent years,a new population of peripheral helper T(Tph)cells has been defined by the expression of CD4+CXCR5’PD-1high.Tph cells share the similar functions with Tfh cells,but exert their functions primarily in peripheral tissues.As the main organ of alcohol metabolism,liver has also been shown to have a significant immunosuppressive regulatory effect.In addition,liver is the main organ invaded and damaged by hepatitis B virus.Many clinical studies have shown that alcohol consumption significantly increases the poor prognosis of hepatitis B infection.Therefore,considering the immunomodulatory effect of alcohol,intrahepatic immunosuppression,and the characteristics of hepatitis B virus infection,we explored the effect of alcohol consumption on intrahepatic immune microenvironment and the clearance of HBV through the establishment of alcohol consumption model and HBV infection model.Methods1.The alcohol intake model and healthy control model of 4-week-old male mice were established by feeding Lieber-Decarli liquid alcohol diet and control liquid diet.2.After 4 weeks of feeding,the mice were sacrificed and the liver and spleen were processed and examined by flow cytometry and immunofluorescence.3.Alcohol consumption significantly promoted the secretion of TGF-β by CD4+T cells and decreased the frequency of intrahepatic Tph and Tfh cells in CD4+ cells,but did not significantly affect the frequency of intrahepatic Treg cells and the expression of CTLA-4 and PD-1 proteins.4.On the basis of alcohol intake model mice and healthy control mice,HBV model was established by high-pressure tail vein injection of PAAV-HBV1.2 plasmid.Then blood was collected from the inner canthus vein of the mice,and the changes of HBsAg,HBeAg and anti-HBsAg specific antibody in serum were dynamically observed.Results1.We found that alcohol significantly increased the expression of Fas protein on pan-B(B220+)cells and plasma cells(CD 13 8+)and the secretion of intrahepatic CD19+B cell inhibitory cytokines(IL-10,TGF-β).2.After four weeks of feeding,the mice were sacrificed and their livers and spleens were collected.The changes of humoral immune-related cells in the liver and the secretion of IL-21 by immune cells in the spleen were analyzed by flow cytometry.3.Alcohol consumption significantly promoted TGF-β secretion by CD4+T cells while decreasing intrahepatic Tph,the frequency of Tfh cells in CD4+T cells.However,it did not significantly affect the frequency of Treg cells and the expression of CTLA4 and PD-1.4.Correlation analysis showed that the frequency of Tph cells was negatively correlated with the expression of Fas protein on plasma cells and the secretion of TGFβ by CD19+B cells.5.Alcohol consumption changed the compositions of CD4+T cells and CD8+T cells in the liver6.Alcohol consumption caused a significant reduction in the area of the splenic GC B cells,as well as a significant reduction in the secretion of IL-21 by TFH-like cells and CD8+PD-1+cells in the spleen.7.The levels of HBsAg and HBeAg in serum were increased and the clearance of HBsAg was delayed in alcohol-intake mice model compared with non-alcohol intake mice.In addition,alcohol consumption leads to a decrease in anti-HBsAg antibodies in the serum.ConclusionsUsing this animal model,we found that alcohol consumption inhibited intrahepatic humoral immune pathways and altered the compositions of intrahepatic T cell subsets.Alcohol consumption also significantly inhibited the secretion of IL-21 by intrasplenic immune cells and the area of GC B cells,and significantly delayed the clearance of HBV infection and antibody production.In conclusion,our study provides more evidences for the damage of liver caused by alcohol and the alcoholic liver disease,and provides more evidences for the abstinence of alcohol in HBV infected patients.