Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1994: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
Research Abstract |
A monoclonal antibody, 1-23, which recognizes a novel cell surface antigen on immature murine thymocytes (designated as IMT-1 for immature thymocyte antigen-1) was prepared.IMT-1 was found to be expressed on 40-50% of CD4^-8^- (DN), 5-10% of CD4^-8^+ and 5-20% of CD4^++^8 (DP) thymocytes in adult mice, but not expressed on CD4^+8^- thymocytes or peripheral T lymphocytes. In the subset of DN thymocytes, IMT-1 was detected on 40 to 50% of the heat stable antigen^+ (HSA^+), 15% of CD44^+25^+,70% of CD44^-25^+ and 70% of CD44^-25^- populations, whereas it was not detected on HSA^- and CD44^+25^- populations. In fetal thymuses, IMT-1 was expressed on a minor population of thymocytes at day 14.5 and 15.5 of gestation. However, at day 16.5 of gestation, a majority of DN as well as DP thymocytes became IMT-1 positive. These results shows that the expression of IMT-1 is correlative to that of pre-TCR.Addition of the 1-23 antibody to the long-term fetal thymus organ culture reduced the DP thymocyte population. These results indicate the possibility that the IMT-1 may be involved in the regulation of thymocyte differentiation.
|