AKR mice, which produce high titers of ecotropic virus, were crossed with NZB mice, which produce titers of xenotropic virus. Spleen, marrow, and lymph node cells of the F1 hybrid produced high titers of ecotropic and xenotropic viruses. However, expression of ecotropic virus by both thymus cells and peripheral T cells of the F1 was severely restricted. Despite simultaneous expression of ecotor...

An approach toward elucidation of the mechanisms of action of mammalian leukemia viruses has been made by the generation in tissue culture of recombinant viruses between a potent murine leukemia virus (MuLV), Rauscher-MuLV, and an endogenous xenotropic mouse type-C virus, BALB:virus-2, without known malignant potential. Using a double selection system devised to select against the temperature-s...

The thymus has a central role in the pathogenesis of l eukemia in AKR mice. Thymectomy great ly reduces the incidence of l eukemia (1). Moreover, v i r tua l ly all t issues of AKR mice express high t i ters of Gross (ecotropic, N-tropic) virus (2), but neoplasms develop regular ly only in the thymus. The thymus of the AKR mouse is also the site of two impor tant virological changes tha t occur...

INTRODUCTION This study confirmed the absence of natural infection with Xenotropic murine leukemia virus-related virus (XMRV) or XMRV-related disease in human populations of the Brazilian Amazon basin. We demonstrated that 803 individuals of both sexes, who were residents of Belem in the Brazilian State of Pará, were not infected with XMRV. METHODS Individuals were divided into 4 subgroups: h...

Gammaretrovirus-like sequences occur in most vertebrate genomes. Murine Leukemia Virus (MLV) like retroviruses (MLLVs) are a subset, which may be pathogenic and spread cross-species. Retroviruses highly similar to MLLVs (xenotropic murine retrovirus related virus (XMRV) and Human Mouse retrovirus-like RetroViruses (HMRVs)) reported from patients suffering from prostate cancer (PC) and myalgic e...

A line (BL/RLi2-NP) of C57BL mouse cells derived from an X-ray-induced thymic lymphoma was free of murine leukemia virus (MuLV) and expressed no viral antigens as determined by potent antisera reactive with group-specific determinants of MuLV p30 and gp70 polypeptides. However, using an antiserum directed against the gp70 of the VL-3 isolate of radiation leukemia virus, which reacted predominan...

In these studies, we have shown data that are consistent with the hypothesis that mink cell focus-inducing viruses (MCF) play an important role in the generation of an erythroproliferative disease developing after injection of certain strains of newborn mice with ecotropic Friend murine leukemia virus (F-MuLV). Resistance to this disease is correlated with the endogenous expression of an MCF/xe...