A group of monoclonal antibodies reactive with the human thymocyte differentiation antigens-Production and specificity analysis / 中国免疫学杂志

ABSTRACT

In a fusion of BABL/C murine spleen cells immunizated with human fetal thymocytes and P_3X_(3)Ag_(,3), myeloma cells, six monoclonal antibodies(McAb) were produced. They were termed HIT_1. HIT_2. HIT_3. HIT_4.HIT_(6-1) and HIT_(6-2), respectively. The specificity of these McAbs were analysed by indirect immunofluorescence technique and FACS.Results showed that they reacted with 80～90%thymocytes,but hardly with peripheral blood mononuclear cells and spleen cells in adults,and nonreactive with red blood cells, granulocytes and platelets, According to their reaction with the tonsil cells, we can divide these six McAbs into three groups: Groupl including HIT_1, HIT_2, and HIT_(?) McAbs reacted approximately with 1/3 tonsil cells; basically GroupⅡ including HIT_(6-1) and HIT_(6-2) McAbs gave negative reaction with tonsil cells; GroupⅢ McAb HIT_4 reacted with 15% tonsil cells, which suggested these were a heterogeneous group McAbs with different specificities. In comparision with OKT series of McAbs in thymus, peripheral blood and tonsil, HIT_(1-3) are similar to OKT_(10) and,HTT6-l and HIT_(6-2) are just like OKT_6,but HIT_4 seems to be a new McAb different frOm HIT_(1-3) and HIT_(6-1) HII_(6-2). The competitive binding assay showed that HIT_(6-1) and HIT_(6-2) labeled with FITC can be inhibited by unlabeled HIT_(6-1) and HIT_(6-2) each other and can also be blocked by OKT_6, suggesting further these antibodies recognized a same epitope on thymocytes. Cross reaction were also demonstrated on HIT_1, and HIT_2 but not on HIT_3, suggesting HIT_1 and HIT_2 recognized the same determinant and HIT_3 recognized another. So six antibodies are McAbs against T cell differentiation antigens.They are useful for research the differentiation of T cells and the classification of malignant lymphadenosis diseases.