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Biomedical subjects

R J Huebner

Publications and source records attributed to R J Huebner.

At least 163 records · Page 9Linked to original sources
PubMed1970

Trans-species rescue of defective genomes of murine sarcoma virus from hamster tumor cells with helper feline leukemia virus.

This report describes a trans-species rescue of defective MSV genome with helper leukemia virus derived from cats. This rescue was achieved by in vitro co-cultivation of hamster tumor cells with feline embryo cells in the presence of helper feline leukemia virus (FeLV), or by inoculation of tumor cells into FeLV-infected newborn cats. The rescued focus-forming viruses produced foci in feline embryo cultures but not in cultures of mouse, rat, and hamster species. One isolate was tested and found to induce sarcoma in a kitten. Antigenic and viral interference studies indicated that the focus-forming virus has the viral envelope of FeLV. Virus stocks consisted of a mixture of focus-forming particles and a 1000-fold excess of helper FeLV. Virus assay pattern in feline embryo cultures with or without added helper FeLV indicated that this helper virus is required for the transformation of feline cells.

Animals↗
PubMed1970

Hamster-tropic sarcomagenic and nonsarcomagenic viruses derived from hamster tumors induced by the Gross pseudotype of Moloney sarcoma virus.

Hamster sarcomas induced by the Gross pseudotype of Moloney sarcoma virus yielded a virus sarcomagenic for hamsters but not mice. This virus was able to produce foci on hamster embryo cells, but not on mouse embryo cells. A hamster-tropic nonfocus-forming helper virus was also found in the viral stocks. These hamster-tropic viruses are not immunologically related to the murine viruses in the original inoculum but appear to represent indigenous C-type RNA viruses of the hamster.

AKR murine leukemia virus↗
PubMed1970

DNA polymerase activity associated with RNA tumor viruses.

C-type RNA viruses, originating in mouse, cat, hamster, and viper, catalyze the synthesis of DNA from its constituent deoxyribonucleoside triphosphates. Both the rate and extent of the reaction were significantly enhanced by brief treatment of the intact virus with ether. A proportion of the newly synthesized DNA was associated with virions when intact virus was used as template; this was not the case with ether-treated virus. In both cases, DNA extracted from the reaction mixture sedimented slowly, at about 2-4 S.

Animals↗
PubMed1970

Group-specific antigen expression during embryogenesis of the genome of the C-type RNA tumor virus: implications for ontogenesis and oncogenesis.

Tests for the group-specific antigen of the C-type RNA tumor virus showed that mouse embryos of all strains tested, at some stage of development in utero, revealed detectable titers of group-specific antigen in one or more of their tissues; younger, rather than older, embryos were likely to be positive, particularly in those strains which normally reveal little or no expression of the RNA genome postnatally. The antigens were found in embryos of low-leukemia strains, free of infectious virus. These new findings support a previously stated hypothesis that the genome of RNA tumor viruses, mostly switched off for infectious virus expression, is vertically transmitted as part of the natural genetic apparatus of normal mouse cells. Since group-specific antigens have also been described in chick embryos and immunological tolerance to homologous group-specific antigens has been demonstrated in hamsters and cats as well as in mice and chickens, the hypothesis has been extended to include vertebrate cells in general. Finally, the high incidence and titers of the group-specific antigen suggest that the genes for RNA tumor virus, which later in life act as determinants of cancer, may be important also as gene determinants in the developing embryo.

Animals↗
PubMed1970

Host-range restrictions of murine leukemia viruses in mouse embryo cell cultures.

Murine leukemia virus strains fall into three categories with respect to their ability to propagate in cells of National Institutes of Health (NIH) Swiss and BALB/c mouse embryos. Cultures of NIH cells are 100- to 1,000-fold more sensitive to "N-tropic" strains than BALB/c cell cultures, but are 30- to 100-fold less sensitive to "B-tropic" strains. Some virus strains (dually tropic or "NB-tropic") propagate equally well in both cells. M-MSV pseudotypes show the host-range characteristics of the virus supplying the envelope, both in vitro and in vivo. The host-range characteristics appear to be genetically determined and could not be explained by host-induced modification or virus mixtures. There was no correlation between host range and Gross-AKR or FMR serotype.

Animals↗