The Study Of Phenotypic Characteristics Of Monocytes In Primary Biliary Cirrhosis And It Is Affection On CD4~+T Polarization

Primary biliary cirrhosis, characterized histologically by intrahepatic bile duct inflammation and damage, is a chronic and progressive cholestatic autoimmune disease. Although the pathological mechanism is still unknown, immune factors play an important role in PBC development. Recent studies showed that the small interlobular bile ducts injury and liver fibrosis are closely related with monocytes infiltration and abnormal activation of T cell. Monocytes are not only important cells of the innate immune response, but also regulate the adaptive immune response via antigen-presenting, secreting cytokines. Human peripheral blood monocytes are heterogeneous and conventionally subdivided into two subsets, CD16-and CD16+,based on CD16expression. Human monocyte subsets are defined into three by new nomenclature, where the minor CD16+population is further segregated into two smaller subpopulations, CD14hhigh CD16+and CD14dim CD16+. The CD16+cells expresse higher HLA-DR, costimulatory molecules, and produce higher pro inflammatory cytokines after stimulation and expanding under infectious or inflammatory conditions, so it is also known as inflammatory monocytes. Accumalating evidences show that inflammatory monocytes upregulated and play a pivotal role in certain infections and autoimmune diseases has been gradually attracting attention. In the PBC disease, the condition of monocytes and the relationship with PBC pathological mechanism are still unknown. So, in this paper, we investigated the monocytes characters and the effection of monocytes on CD4+T celles differentiation in PBC patients. Objectives:This paper based on the frequency of inflammatory monocyte subsets in PBC patients to explore the relationship with clinical laboratory indexes of PBC liver damage; Also investigate the correlation between inflammatory monocyte subsets and CD4+T cells and explore whether the inflammatory monocytes are responsible for CD4+T cells differentiation.Methods:Peripheral blood mononuclear cells are isolated from PBC patients and control groups. Flow cytometry assay was carried out to detect the percentages of different subsets of monocytes and Thl/Th17cells. We sorted CD4+T cells and monocyte subsets form PBC patients, then purified CD4+T cells were co-cultured with autologous CD16-cells or CD16+cells. In the transwell culture system, sorted CD4+T cells were co-cultured with autologous CD16+cells. Gene expression level of IL-12p35、IL-12p40and IL-18in monocyte subsets were detected by RT-PCR, then antibody blocking agent was added into the CD16+cells and CD4+T cells co-culture system to assess the intracellular cytokine production.Results:1. In PBC group, CD14high CD16+and CD14dim CD16+monocyte subsets were significantly increased compared with HC group (P<0.05),and CD14dim CD16+subset also increased compared with CHB group (P<0.05);2. In PBC patients, elevated proportions of circulation CD14dimCD16+monocytes were positively correlated with serum ADA levels (r=0.582, P<0.01) and CRP levels (r=0.629, P<0.01), but no correlation with serum ALT, AST, GGT and ALP levels;3. The frequencies of CD16+monocytes were positively correlated with Th1%in CD4+T cells (r=0.545, P<0.01), but no correlation with Th17%;4. In the CD16+cells and CD4+T co-culture system, the frequencies of Thl was higher compared with CD16-and CD4+T co-culture system. Furthermore, the frequency of Th17has no statistically significant difference;5. CD16+cells, contacting with CD4+T cells directly, produce more IFN-Y (P>0.05);6. CD14dim CD16+monocytes expressed higher levels of IL-12p40than CD14high CD16-cells. In addition, anti-IL12p40signifacantly inhibited IFN-γ production (P>0.05) Conelusions:The results indicated that the CD14high CD16+and CD14dim CD16+monocytes significantly increased in the peripherial blood of PBC patients, and CD14dim CD16+monocytes were closely related with ADA and CRP serum levels; furthermore, the results also showed the polarization of Thl cells was mediated by inflammatory monocytes via cell-cell directly contact and IL-12pathway.