Isoforms of leukocyte common antigen (CD45) on human neoplastic hematopoietic cell lines

Leukocyte common antigen (LCA) isoform expression patterns were examined on different human hematopoietic cells and cell lines with the aid of the immunoblotting technique utilizing two anti-LCA monoclonal antibodies elicited by an ALL cell line and able to detect four isoforms (180, 195, 205 and 220 kDa) of LCA on peripheral blood lymphocytes from healthy donors and some neoplastic hematopoietic cell lines. Fourteen leukemia/lymphoma cell lines of different origin and immunophenotype, as well as three nonhematopoietic human tumor cell lines were examined by this technique. Human hematopoietic cell lines expressed two to four different polypeptide chains (180, 195, 205 and 220 kDa). Non-T, non-B cell lines, some B-cell lines and monocyte lymphoma cell line U 937 predominantly expressed higher molecular weight isoforms. In myeloid leukemia cell lines examined the expression of lower molecular weight isoform(s) predominated. Individual variability in LCA isoform patterns on cell lines precluded the strict correlation between these patterns and immunophenotype of the examined cell lines.