Changes in gamma-globin gene methylation accompany the fetal to adult globin switch in man. Using somatic cell hybrids made by fusing mouse erythroleukemia and human fetal erythroid cells, we asked whether methylation is a cause or a consequence of gamma-gene inactivation during development. These hybrids initially express human gamma-globin but switch with time in culture to adult globin gene ...

Processing of the laminin-5 (Ln-5) gamma 2 chain by membrane-type-1 matrix metalloproteinases (MT1-MMP) promotes migration and invasion of epithelial and tumor cells. We previously demonstrated that MT1-MMP cleaves the rat gamma 2 chain at two sites, producing two major C-terminal fragments of 100 (gamma 2') and 80 (gamma 2 x) kDa and releasing a 30-kDa fragment containing epidermal growth fact...

Anti-Fc gamma R IgM monoclonal antibodies (mAbs) isolated from lipopolysaccharide-stimulated spleen cells from tightskin (TSK) mice were found to be polyspecific, reacting with a wide variety of molecules, including double-stranded DNA, topoisomerase, RNA polymerase, and different collagen types. Approximately 60% of the polyspecific IgM mAbs have anti-Fc gamma R specificity. These anti-Fc gamm...

Studies of human NK cells and their role in tumor suppression have largely been restricted to in vitro experiments which lack the complexity of whole organisms, or mouse models which differ significantly from humans. In this study we showed that, in contrast to C57BL/6 Rag2(-/-)/gamma(c) (-/-) and NOD/Scid mice, newborn BALB/c Rag2(-/-)/gamma(c) (-/-) mice can support the development of human N...

All pharmacologic agents that induce fetal hemoglobin (Hb) have been discovered with in vivo studies of humans, macaques, and baboons. We tested whether transgenic mice carrying human fetal (gamma) globin genes provide a model for studying the pharmacologic induction of HbF in the adult. In initial studies, phenylhydrazine-induced hemolytic anemia, 5-azacytidine, butyrate, or combinations of th...

A sensitive two-step simultaneous enzyme immunoassay (EIA) for human gamma interferon (IFN-gamma) has been developed and used as an in vitro test for human tuberculosis (TB) in comparison with tuberculin skin testing. The EIA was shown to be highly sensitive, detecting less than 0.5 IU of recombinant human IFN-gamma per ml within a linear detection range of 0.5 to 150 IU/ml. The assay was highl...

background programmed cell death (apoptosis) is a physiological process needed to remove unwanted or damaged cells. it has been hypothesized that any failure of programmed cell death leads to the development of neoplasm. identifying new agents which induce apoptosis in tumor cells is of great significance in treatment of neo­plasms. numerous studies suggest that exposure of tumor cells to stati...

We have examined whether transfected mouse erythroleukaemia (MEL) cells can be used to examine differential expression of human gamma- and beta-globin genes. These cells, which express only their adult globin genes, will transcribe the human adult beta gene but not the fetal gamma genes when they are introduced on an intact human chromosome 11 by cell fusion. However, MEL cells stably transfect...

The most prominent gamma interferon (IFN-gamma)-induced antimicrobial effector mechanisms are the induction of nitric oxide (NO) synthase (NOS) and of indoleamine 2,3-dioxygenase (IDO) activity. We have recently found that human glioblastoma cells and human macrophages inhibit the growth of group B streptococci after stimulation with IFN-gamma. In this report, we show that in addition, human RT...