B cells malignantly transformed by human immunodeficiency virus are polyclonal.

The roles that human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV) play in the genesis of acquired immune deficiency syndrome (AIDS)-related lymphomas are not understood. A human B cell line (B-HIV), developed to study AIDS-related lymphomagenesis, contains EBV and HIV genomes and is malignantly transformed. This line was produced by exposing B cells from an EBV-seropositive donor to HIV.

A model system for regulation of chronic HIV-1 infection in peripheral B lymphocytes.

B-HIV1, an oligoclone of immortalized cells derived from human peripheral B lymphocytes infected in vitro with the TIIIB isolate of HIV-1, produces low levels of replication-competent HIV when propagated in 1% serum, but increases production > or = 5-fold after phorbol myristate acetate (PMA) exposure. Electron microscopy reveals budding of mature virions from the plasma membrane, without concentration in endocytotic spaces. The PMA effect is specific for protein kinase activation, occurring upon exposure of B-HIV1 to those congeners capable of upregulating calcium and phospholipid dependent protein kinase C and susceptible to inhibition by the protein kinase antagonists H-7 and staurosporine.

Suppression of deregulated c-MYC expression in human colon carcinoma cells by chromosome 5 transfer.

Two-thirds of sporadic colon carcinomas express elevated levels of the c-MYC protooncogene. In addition, most colon carcinoma cell lines show constitutive elevated expression (10- to 40-fold over normal) of MYC RNA and protein that is not modulated in response to a mitogenic stimulus. Indirect immunofluorescence has been used to detect c-MYC protein in such cell lines, in hybrid cells resulting from fusions of such lines with cells that regulate MYC normally, and in carcinoma cells to which a normal copy of chromosome 5 has been transferred by microcell fusion.

Does HIV infection of B lymphocytes initiate AIDS lymphoma? Detection by PCR of viral sequences in lymphoma tissue.

Individuals infected with HIV (Human Immunodeficiency Virus) frequently develop B cell non-Hodgkins lymphoma. Although previous studies have failed to document the presence of HIV sequences in these tumors, the recent demonstration of malignant transformation of primary B lymphocytes by HIV-1 has prompted us to reinvestigate this issue. We have examined DNA extracted from 7 lymphomas and 5 lymphadenopathy specimens for HIV LTR (long terminal repeat), gag, and tat sequences using the polymerase chain reaction (PCR).

Isolation, properties and cellular distribution of D1, a chromosomal protein of Drosophila.

The protein D1 was obtained from nuclei of Drosophila melanogaster embryos and purified by perchloric acid fractionation and preparative gel electrophoresis. In nuclei its amount is approximately 1% of the amount of DNA by weight. D1 is soluble in 5% perchloric acid and extractable from nuclei by solutions of moderate ionic strength (0.