RESUMEN
OBJECTIVE: To study the immunoregulatory effect of hepatitis B virus (HBV) e antigen (HBeAg) on peripheral blood monocytes (PBMCs). METHODS: PBMCs were isolated from patients with chronic hepatitis B (CHB; both HBeAg- and HBeAg+) and healthy controls, and cultured with recombinant HBeAg. The HBeAg-induced changes in expression of PD-1/PD-L1 were measured by flow cytometry of the cells and in secreted cytokines were measured by enzyme-linked immunosorbent assay of the supernatants. Comparisons between two groups were made by the independent-samples t-test; the relationship between PD-1/B7-H1 level and HBV DNA copy number was evaluated by Spearman's correlation analysis. RESULTS: Exposure to HBeAg led to a significant decrease in CD3+CD4+ T lymphocyte-specific expression of IFNa for both the CHB patients' and healthy controls' samples (t = 2.382 and -4.190 respectively, P less than 0.01). For the HBeAg- CHB patients' and healthy controls' samples, the HBeAg exposure led to increased levels of secreted cytokines IL-6, IL-10 and TNFa (t = 2.504, 3.583 and 4.324, P less than 0.01 and t = 3.542, 6.246 and 5.273, P less than 0.01 respectively) and of CD14+ PBMC-specific expression of PD-L1 (t = 4.815 and 3.454, P less than 0.05 respectively). Compared to the HBeAg-negative CHB patients' and healthy controls' samples, the HBeAg+ CHB patients' samples had significantly lower CD3+CD4+ T cell-specific expression of IFNa (t = -3.177 and -4.541, P less than 0.01 respectively), but significantly higher levels of secreted IL-4 (t = 3.382 and 4.393, P less than 0.01 respectively), of CD3+ T cells-specific expression of PD-1/PD-L1 (t = 4.755, 2.942 and 4.518, 4.595, P less than 0.01 respectively), and of CD14+ T cells-specific expression of PD-L1 (t = 5.092 and 5.473, P less than 0.01 respectively). The CD3+ T cells-specific expression of PD-L1 was significantly higher in the samples from HBeAg- CHB patients than from the healthy controls (t = 3.214, P less than 0.01). CONCLUSION: HBeAg was able to down-regulate the production of Th1-type cytokines (IFNgamma), and up-regulate the secretion of Th2-type cytokines (IL-6, IL-10) and the expression of PD-1/PD-L1on monocytes. These changes are conducive to the formation of immune tolerance to HBV. Therefore, HBeAg may play an important role in immune tolerance to chronic HBV infection.
Asunto(s)
Antígenos e de la Hepatitis B/inmunología , Hepatitis B Crónica/inmunología , Balance Th1 - Th2 , Adulto , Estudios de Casos y Controles , Células Cultivadas , Femenino , Antígenos e de la Hepatitis B/genética , Hepatitis B Crónica/sangre , Humanos , Interferón gamma/inmunología , Interleucina-10/inmunología , Interleucina-6/inmunología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/inmunología , Células TH1/inmunología , Células Th2/inmunologíaRESUMEN
OBJECTIVES: In order to investigate the relationship among the toll-like receptor 2 (TLR2), hepatitis B e antigen and HBV DNA, the expression levels of TLR2 on peripheral blood monocytes of chronic hepatitis B (CHB) patients as well as on their monocytes stimulated by ligand of TLR2 (Pam3CSK4) and HBeAg were analyzed. METHODS: Sixty-eight adults with CHB were enrolled, including 37 HBeAg-positive patients, 17 HBeAg-negative and HBV DNA negative patients, and 14 HBeAg-negative and HBV DNA positive patients. Sixteen healthy volunteers were also studied as controls. TLR2 expression levels on their peripheral blood monocytes stimulated with Pam3CSK4 or not stimulated were analyzed by FACS Caliber. The relationship of the expression levels of TLR2, HBeAg and HBV DNA were also analyzed. The level of TLR2 on peripheral blood monocytes of healthy volunteers and HBeAg-negative CHB patients stimulated by HBeAg was examined for six hours. RESULTS: The TLR2 expression levels on CD14+ cells were significantly reduced in HBeAg-positive patients (47.57%+/-21.40 %) compared to both healthy volunteers (76.51%+/-7.46%) and HBeAg-negative patients (HBV DNA positive group 73.2%+/-14.2%, HBV DNA negative group 75.2%+/-11.3%); but there was no difference between those of the HBeAg-negative patients and the healthy volunteers. Expression levels of TLR2 on monocytes stimulated by TLR2 ligand in HBeAg-positive patients were obviously increased, and reached the basic levels of the healthy volunteers and the HBeAg-negative patients. The expression levels of TLR2 on monocytes stimulated by HBeAg of the healthy volunteers and the HBeAg-negative patients were markedly reduced. CONCLUSIONS: In the presence of HBeAg, HBV down-regulates the expressions of TLR2 on CD14+ cells from peripheral blood, and there is no correlation between HBV-DNA and TLR2. Pam3CSK4 can boost the TLR2 expression in HBeAg-positive patients. The proposed interaction between HBV and TLR2 may provide an important clue to explain the reasons of the establishment of persistent HBV infection.