Effects of inhibitory and enhancing polypeptides from HCV core region on cytotoxic T cell functions / 第三军医大学学报

Objective To investigate the pathogenesis of cytotoxic T cell (CTL) dysfunction in patients with HCV infection. Methods CTL detecting system was established. Two polypeptides which could enhance CTL function and two polypeptides which could inhibit CTL function were selected and cross-combined. BALB/c mice were immunized by subcutaneous injection of the combined polypeptides, and the CTL activity in mouse spleen cells was detected by LDH release test. Results CTL activity in BLAB/c mice immunized by polypeptides in the core region of HCV could be enhanced by CPA10 (5-23 aa) and inhibited by CPA9 (39-74 aa). CTL activity in the mice could be enhanced by polypeptides from the HCV core region, CPB2+CPB8, and CPB6+CPB8, respectively. There was no obvious difference between CPB2+CPB7, CPB6+CPB7 and the negative control. Two-factor analysis of variance showed that there was reciprocal action between the inhibitory and enhancing polypeptides from the HCV core region. Conclusion CTL activity in BLAB/c mice can be detected stably by LDH. There is an interactive effect between the inhibitory and enhancing polypeptides from the HCV core region.

Effects of polypeptides from HCV core region on the function of cytotoxic T cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the pathogenesis of cytotoxic T cell (CTL) dysfunction in patients with HCV infection.</p><p><b>METHODS</b>BALB/c mice were immunized by subcutaneous injection of polypeptides from HCV core region, and the CTL activity of mouse spleen cells was detected by the LDH release test. Two polypeptides which can enhance CTL function and two polypeptides which can inhibit CTL function were selected and cross-combined. BALB/c mice were immunized using the combined polypeptides and the CTL activities were detected afterwards.</p><p><b>RESULTS</b>CTL activity was inhibited by CPA9 (39-74 amino acids), CPB7 (67-76 amino acids) and CPB8 (71-80 amino acids), and promoted by CPA10 (5-23 amino acids), CPB6 (63-72 amino acids) and CPB2 (131-140 amino acids). Using single factor analysis of variance, the CTL activity in the mice could be enhanced by polypeptides from the HCV core region, CPB2+CPB8, CPB6+CPB8, respectively. There was no obvious difference between CPB2+CPB7, CPB6+CPB7 and negative control.</p><p><b>CONCLUSIONS</b>CPA9, CPB7, and CPB8, the 3 polypeptides from HCV core region play an inhibition role and CPA10, CPB6, and CPB2 play an enhancement role in CTL activity in mice. The inhibition and enhancement functions of the polypeptides from HCV core region interact each other.</p>

Comparative study on hepatoma cell line 7721 and human fetal hepatocytes for in vitro culture of hepatitis C virus / 第三军医大学学报

Objective　To study the similarities and differences on in vitro replication and expression of hepatitis C virus (HCV) between human fetal hepatocytes (HFH) and 7721 cell line. Methods　Human fetal hepatocytes and a hepatoma cell line 7721 were incubated with a serum from hepatitis C patient. After incubation, the presence of HCV RNA, the expression of HCV NS3 antigens in cells and/or supernatant were examined by RT-PCR, in situ hybridization and immunohistochemistry, respectively. Results　It was found that: ①The intracellular HCV RNA was first detected on d 2～3 post-incubation and then could be intermittently detected in cells and/or supernatant subsequently (HCV RNA could be detected in 7721 cells during a period of at least 66 days. In HFH, HCV RNA could be detected up to 25 days after incubation); ②HCV-NS3 antigen could be expressed in infected cells; ③Minus-strand RNA of HCV was mainly located within cytoplasm by in situ hybridization. Conclusion　The results suggest that both the fetal hpatocytes and the hepatoma cell line 7721 are susceptible to HCV, and especially 7721 cell line can stably support HCV replication in vitro and may be used as the target cell for long-term cultures of HCV.

A preliminary study of effects of hepatitis C virus nucleopolypeptides on specific cytotoxic T cells / 中华传染病杂志

Objective To explore the mechanism of CTL dysfunction in HCV infected person, to provide a theoretical basis for further understanding the pathogenesis of hepatitis C and the development of HCV vaccines. Methods HCV nucleopolypeptides were selected and synthesized with the method of solid phase synthesis. BALB/c mice were immunized subcutaneously with HCV nucleopolypeptides, and CTL activity of mice was detected by LDH releasing test. Results CTL of mice could be inhibited by HCV nucleopolypeptides residues 39-74, 67-76, 71-80 and enhanced by HCV nucleopolypeptides residues 5 23,63 72,131 140. Conclusion The function of CTL can be suppressed and intensified by different HCV nucleopolypeptides.

A study of the specific cytotoxic T cell of BALB/c mice detected by LDH / 第三军医大学学报

Objective To establish a simple animal model and the cytotoxic T cell(CTL) detecting system for the studies of the effects of CTL on HCV infection. Methods The CTL activity in BLAB/c mice immunized by polypeptides in the core region of HCV was detected with lactic dehydrogenase (LDH) by using SP2/O cells as the target cells. Results CTL activity in BLAB/c mice immunized by polypeptides in the core region of HCV could be detected with LDH. The activity could be enhanced by CPA10(5～23 aa) but inhibited by CPA9(39～74 aa). Conclusion CTL activity in BLAB/c mice can be detected stably by LDH.