[Immunological characterizations of adult T cell leukemia cells]

Profiles of antigens, associated with activation of normal T cells, on adult T cell leukemia (ATL) cells obtained from ATL patients with various clinical stages (acute, chronic, smoldering), were examined. The expressions of Ki 67, OKT 9 and CD 38 antigens were correlated with the spontaneous 3H-thymidine uptake and also with the severities of the disease. CD 25 and CD 28 antigens were expressed on ATL cells from all clinical stages. A loss of CD 7 antigen was observed in peripheral blood ATL cells. HLA-DR antigen was detected on smoldering and chronic ATL cells, but the antigen was not present on acute ATL cells. Surprisingly, both of these antigens were present on lymph-node ATL cells, which proliferate 15-50 fold more than peripheral blood ATL cells do. These findings confirmed that ATL cells preferentially proliferate in lymph nodes, and CD 7 and HLA-DR antigens might contribute to the proliferation. A cDNA named pLD 78 was isolated from a library constructed from the poly (A)+RNAs of tumor promoter and mitogen stimulated human tonsillar lymphocytes, using a differential hybridization technique. pLD 78 DNA sequence codes for a polypeptide consisting of 92 amino acid residues, including a putative signal sequence. A computer search with the National Biomedical Research Foundation library showed that this proteis had homologous sequences with several proteins, which are involved in inflammation and tumorigenesis. The highest homology was found with mouse macrophage inflammatory protein (MIP).(ABSTRACT TRUNCATED AT 250 WORDS)