The role of HBsAg-specific CD4 T cells in both the generation of chronic hepatitis and the immunological tolerance to HBV

1997 Fiscal Year Final Research Report Summary

• Project/Area Number: 07670623
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Gastroenterology
• Research Institution: Tokyo Women's Medical College
• Principal Investigator: KAMOGAWA Yumiko Department of Gastroenterology, Tokyo Women's Medical College, Instructor, 医学部, 助手 (60211174)
• Project Period (FY): 1995 – 1997
• Keywords: chronic hepatitis type B / CD4 cells / immunological tolerance

Research Abstract

To elucidate the role of Hepatitis B surface antigen (HBsAg) reactive CD4 cells in both the generation of chronic hepatitis and the immunological tolerance to hepatitis B virus (HBV), we attempted to establish several HBsAg-reactive clones by using peripheral blood mononuclear cells obtained from HB vaccinees. We established at least 8 CD4 clones from 2 HB vaccine responders (HR) and 2 HB vaccine non-responders (NR). All these clone responded to HBsAg but not to other antigens. To examine their features precisely, we have examined both the utilization of TCR Vbeta gene as well as their cytokine synthesis of these clones. We found that at least three different TCR Vbeta gene were utilized in these clones established from either HR or NR.Simultaneously, while many of these clones secreted gammaIFN, some of them secreted both gammaIFN and IL-4. From these results, we can assumed that heterogeneous HBsAg-reactive clones equally existed both in HR and NR and hence t the immunological response to HBsAg may be mainly regulated by potent suppressive effect rather than the balance between the Thl and Th2. Recently, we were able to establish HBsAg-reactive CD8 clones having a potent suppressive activity on the function of these CD4 clones. The analysis of these clones are under investigated.