A monoclonal alloantibody detecting a polymorphism of the rat leucocyte common (LC) antigen.

A monoclonal antibody, NDS 58, was produced by fusing the rat myeloma line Y3 Ag 1.2.3 with spleen cells from AS rats immunized with LEW thymocytes. The determinant recognized by this antibody is leucocyte-specific and present on all thymocytes, lymph node lymphocytes and some bone marrow cells. The strain distribution of NDS 58 was consistent with it being directed at the RT7a allele. Biochemical studies established that this antigen was carried on a cell surface glycoprotein with an apparent molecular weight on thymocytes of 190,000. This study confirms that the alloantigen originally designated Ly-1, and now termed RT7, is an allodeterminant of the LC molecule, and the controversy in this area, particularly with regard to the ART-1 alloantigen, is discussed.