Differential methylation of class I histocompatibility antigen genes in T-cell lines derived from two different types of T-cell malignancies

HLA class I antigens on normal and leukemic cells (quantitative analysis)

A monomorphic anti-Class I monoclonal antibody, ST01, found in our laboratory, was used to quantify Class I antigens on normal and leukemic cells, using a "CELISA" technique. Saturation graphs were used to compare the quantity of Class I antigens on normal PBL (25 cases) with that on the following types of leukemic cells: a) common acute lymphoblastic leukemias (cALL) (11 cases), b) mature B lymphocytic proliferations (16 cases), c) T hemopathies (9 cases), d) non-lymphoid leukemias (9 cases). In most cases the quantity of HLA Class I antigens was greatly reduced. No correlation was found between the quantitative expression of Class I antigens and the stage of maturation in each cell type, nor was any correlation found between the quantitative expression of Class I antigens on the leukemic cells and the proliferation of leukemic cells in the peripheral blood.

Long-term inhibition of human T-lymphotropic virus type III/lymphadenopathy-associated virus (human immunodeficiency virus) DNA synthesis and RNA expression in T cells protected by 2',3'-dideoxynucleosides in vitro

We report that 2',3'-dideoxyadenosine and 2',3'-dideoxycytidine inhibit retroviral DNA synthesis and mRNA expression in T cells exposed to the virus that causes acquired immunodeficiency syndrome, and afford such cells long-term protection in vitro under conditions of substantial viral excess. Both 2',3'-dideoxyadenosine and 2',3'-dideoxycytidine appear to completely block reverse transcription from viral RNA to viral DNA. Viral mRNA expression is also not detected in cells protected by the drugs throughout 30 days of culture following exposure to the virus. Purine and pyrimidine analogues as 2',3'-dideoxynucleoside-5'-triphosphate serve as substrates for the human T-lymphotropic virus type III/lymphadenopathy-associated virus reverse transcriptase to elongate a DNA chain by one residue, after which the chain is terminated. Cloned normal helper/inducer T cells exposed to a cytopathic dose of the virus, but protected by the drugs, respond normally to specific antigen in vitro. These results suggest that the drugs could be promising agents for further studies in the experimental treatment of patients infected with retroviruses.