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Biomedical subjects

B Chesebro

Publications and source records attributed to B Chesebro.

At least 145 records · Page 8Linked to original sources

Identification of a non-H-2 gene (Rfv-3) influencing recovery from viremia and leukemia induced by Friend virus complex.

The dominant C57BL/10 allele of a single autosomal, non-H-2 gene (Rfv-3) was found to be required for recovery from viremia and leukemia induced by Friend virus complex in H-2b/b mice. In H-2a/a mice, the Rfv-3 gene apparently influenced recovery from viremia in the presence of persistent leukemia because these mice lacked the appropriate H-2 genotype for recovery from leukemia. The Rfv-3 gene was distinct from the Fv-2 gene because recovery from viremia was seen in recombinant-inbred mice with the Fv-2s/s genotype. Furthermore, backcross studies indicated that Rfv-3 and Fv-2 were not linked. The Rfv-3 gene may act by influencing the specific anti-FV humoral antibody response.

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Antibody-induced modulation of Friend virus cell surface antigens decreases virus production by persistent erythroleukemia cells: influence of the Rfv-3 gene.

The Rfv-3 gene was found to influence the level of Friend leukemia virus production in spleens of leukemic mice later than 30 days after virus inoculation. Rfv-3r/s mice [(B10.A X A)F1 and (B10.A X A.BY)F1] had decreased spleen virus levels 30-90 days after virus inoculation compared to Rfv-3s/s mice [A.BY, A, BALB.B, and (BALB/c X A)F1)]. In (B10.A X A)F1 X A backcross mice the spleen virus titer segregated with the level of viremia. The Rfv-3 gene appeared to act by controlling anti-Friend virus antibody production. The interaction of antiviral antibody with infected cells led to a decrease in release of infectious virus by late leukemic spleen cells in Rfv-3r/s mice to 1/300th that in Rfv-3s/s mice. This decrease in virus release appeared to be due to interference with the virus budding process due to antibody-mediated modulation of virus-induced cell surface antigens.

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Persistence of infectious Friend virus in spleens of mice after spontaneous recovery from virus-induced erythroleukemia.

Persistent infectious virus was detected in the majority of spleens of (C57BL/10 X A.BY)F1 mice after spontaneous recovery from Friend virus-induced erythroleukeima. The Friend murine leukemia helper virus (F-MuLV) was detected in titers up to 3 X 10(5) PFU/g of spleen. The defective spleen focus-forming virus (SFFV) was present in much lower titers and could be detected in cell-free spleen homogenates only after amplification of virus titer by growth of virus in vitro on SC1 cells. The incidence of cells producing F-MuLV alone in spleens after recovery from leukemia was 0.003 to 0.3%, and the incidence of cells producing both F-MuLV and SFFV was less than 0.0001 to 0.01%. In most recovered mouse spleens there appeared to be a selective reduction of SFFV relative to F-MuLV.

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Antibody-induced loss of Friend virus leukemia cell surface antigens occurs during progression of erythroleukemia in F1 mice.

Friend virus (FV)-induced leukemic spleen cells from (B10.A X A)F1 mice were found to lose sensitivity to antibody-mediated lysis during progression of erythroleukemia. This was correlated with a 78% loss of FV-induced cell surface antigens as determined by quantitative absorption of cytotoxic antibodies and with a decreased percentage of leukemic spleen cells showing membrane immunofluorescence with anti-FV antibody. Antigen loss was observed only with virus-induced antigens, and was limited to antigens expressed on the cell surface. FV-induced antigens were regained when low-antigen leukemia cells from late stages of the leukemia were transferred to lethally irradiated nonimmune recipients, but not when these cells were transferred to hyperimmune lethally irradiated recipients. Conversely, when high-antigen leukemic spleen cells from early stages of the erythroleukemia were transferred to hyperimmune irradiated recipients, antigen loss was induced. The immune response to virus-induced antigens appeared to be involved in causing the antigenic changes observed on leukemia cells in this system.

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Lack of erythroid characteristics in Ia-positive leukemia cell lines induced by Friend murine leukemia virus: brief communication.

A group of mouse leukemia cell lines induced by the Friend murine leukemia virus (F-MuLV) was examined for a cell membrane antigens (regulated by the I-region of the H-2 complex), as well as for erythroid characteristics. Erythroid traits tested were hemoglobin synthesis, incorporation of 59Fe into heme, and presence of globin mRNA. Of 19 lines, 13 were positive for erythroid characteristics. All of these 13 lines were a-negative. Of 19 lines, 6 were negative for erythroid characteristics, and 5 of the 6 were a-positive. The data suggested that F-MuLV-induced leukemogenesis may operate in more than 1 cell type. In addition to the primitive erythroid type of cell usually involved in leukemia induced by F-MuLV, nonerythroid Ia-positive cells may also be transformed. The exact origin of the Ia-positive leukemia cells is unknown.

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Rfv-1 and Rfv-2, two H-2-associated genes that influence recovery from Friend leukemia virus-induced splenomegaly.

Two genes, Rfv-1 and Rfv-2, that influence recovery from Friend virus leukemia have been identified within or adjacent to the mouse major histocompatibility gene complex (H-2). Rfv-1 was determined to be in the H-2G or H-2D regions by testing of mice with recombinations both to the left and right of these regions. Rfv-2 was located either in the H-2K or H-2I regions or in the Tla region. The Rfv-2 effect was not seen in the high recovery H-2D(Rfv-1)b/b mice. This could be an indication that this gene is weaker than Rfv-1 in its influence on leukemia. The influence of H-2 on recovery from leukemia appeared to operate in a gene-dose fashion (H-2b/b greater than H-2a/b greater than H-2a/a).

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Studies on the role of the host immune response in recovery from Friend virus leukemia. I. Antiviral and antileukemia cell antibodies.

The humoral immune response to Friend virus leukemia was studied in congenic F1 mice differing in their incidence of recovery from leukemia. Antiviral neutralizing antibodies rose in titer in vivo concurrently with disappearance of viremia and fall in spleen virus levels. Cytotoxic antileukemia cell antibodies also appeared at this time. Passive transfer of these antibodies could inactivate low numbers of leukemia cells in vivo; however, mice of both high and low recovery genotypes produced antibodies in equal titer and recovered from viral infection in spite of striking differences in recovery from leukemic splenomegaly. Mice lacking C57BL genes did not produce antibodies or recover from viremia except in rare instances. Recovery from splenomegaly was found to be influenced by three or more C57BL genes independent of the H-2 complex.

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Studies on the role of the host immune response in recovery from Friend virus leukemia. II. Cell-mediated immunity.

Congenic mouse strains differing only at genes within the H-2 complex were found to have virus-specific cytotoxic effector cells in their spleens during or after recovery from Friend leukemia virus-induced splenomegaly. These effector cells were theta-positive T lymphocytes which functioned in vitro without help or inhibition by B lymphocytes or glass-adherent cells. The antigenic specificities recognized by the effector cells were viral-induced cellular antigens apparently different from those identified by serological techniques.

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Characterization of Ia8 antigen, thy-1.2 antigen, complement receptors, and virus production in a group of murine virus-induced leukemia cell lines.

Ia8, a cell membrane antigen controlled by gene(s) located in the I region of the H-2 complex, was found on 9 of 26 murine leukemia cell lines. Iaddition, 3 of the 9 Ia8-bearing lines had a membrane receptor for antigen-antibody-complement complexes. Six of 26 lines bore the Thy-1.2 antigen. Ia8 and Thy-1.2 antigens were mutually exclusive on the cell lines studied. The strain of virus used to induce the leukemia, the H-2 type of the cells, and the techniques of leukemia cell propagation all appeared to influence the antigenic characteristics of the cell lines obtained. Production of infectious murine leukemia virus in vitro and expression of leukemia virus-induced membrane antigens did not appear to correlate with the presence of I8 or Thy-1.2 antigens or with the H-2 type of the cells.

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Aleutian disease of mink: the antibody response of sapphire and pastel mink to Aleutian disease virus.

The specific antiviral antibody response of sapphire and pastel mink to Pullman strain of ADV has been examined. Sapphire mink inoculated with from 300,000-3 LD50 developed high levels of specific antibody and AD. Pastel mink inoculated with parallel doses of ADV also produced antibody but did not develop AD. The low incidence of AD in pastel mink inoculated with Pullman strain of ADV is probably related to factors other than antiviral antibody.

Aleutian Mink Disease↗

Host genetic control of recovery from Friend leukemia virus-induced splenomegaly: mapping of a gene within the major histocompatability complex.

The influence of the major mouse histocompatibility gene complex (H-2) on the response of mice to Friend leukemia virus was studied in F(1) congenic mice differing only at genes within the H-2 complex. F(1) mice which were H-2(b/b) had a high incidence of recovery from splenomegaly compared to H-2(b/d) or H-2(b/a) mice. In mice with recombinations within the H-2 complex a gene (designated RFV-1), responsible for the Friend virus recovery effect, was found to map near or within the D region of serologically detectable transplantation antigens. Because the incidence of recovery was much higher in F(1)H-2(b/b) mice than in parental H-2(b/b) mice, other non-H-2 host genetic factors also appear to be important to expression of recovery in H-2(b/b) F(1) mice. The mechanisms of action of these genes remain unknown.

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Ultrastructural studies of human and rabbit alpha-M-globulins.

Electron micrographs of isolated human alpha(2)M-molecules, obtained by the negative contrast technique, revealed morphologically homogenous structures resembling a graceful monogram of the two letters H and I. The modal values for the length and width of the alpha(2)M particles were 170 A and 100 A, respectively. Purified rabbit alphamacroglobulins contained about 80% alpha(1)M- and 20% alpha(2)M-globulins. The isolated rabbit alpha(1)M- and alpha(2)M-molecules were morphologically indistinguishable from one another and from human alpha(2)M-molecules. Preliminary immunoprecipitation studies demonstrated that the two rabbit alphaM-globulins were antigenically different. Sedimentation constant determinations gave s(20, w) values of 18.8 and 18.2 for rabbit alpha(1)M and alpha(2)M, respectively.

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The ultrastructure of normal and pathological IgM immunoglobulins.

Free IgM immunoglobulins were examined in the electron microscope using the negative contrast technique. Normal human and rabbit IgM and Waldenström macroglobulins were indistinguishable from one another and revealed flexible spider-like particles with five appendages joining a central ring. The average total span of the molecules was 300 A. The appendages were about 125 x 30 A; the central ring had an outer diameter of approximately 100 A and an inner diameter of 40 A. Some purified 19S IgM preparations tended to form massive aggregates (>/=50S) which, when examined in the electron microscope, revealed enormous clumps of IgM molecules whose appendages were entangled with one another. Electron microscopy of reduced-alkylated IgM revealed total absence of intact spider-like molecules. The predominating structure observed was a round electron-dense knob about 50 A in diameter which in some cases had a fine fiber-like extension with approximate dimensions 100 x 15 A. Rabbit and human IgM molecules with antibody activity to poliovirus dried in sodium tungstosilicate on a carbon film as in preparation for electron microscopy were shown to retain nearly 100% of their poliovirus neutralizing activity after redissolving in a physiological buffer.

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