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M Strand

Publications and source records attributed to M Strand.

106 records · Page 6Linked to original sources
PubMed1975

Structural proteins of mammalian RNA tumor viruses: relatedness of the interspecies antigenic determinants of the major internal protein.

The relatedness of antigenic determinants of purified major core proteins of the murine, feline, RD 114/baboon, and woolly monkey/gibbon ape groups of RNA tumor viruses was examined by competition radioimmunoassay. In assay systems of a homologous antigen and antiserum, high affinity competition for binding to all of the antibodies was observed only with the homologous unlabeled protein; the core proteins of other groups of viruses showed only low affinity binding of a small fraction of antibodies, presumably those reactive with the interspecies determinants, at concentrations of competing protein 10- to 100-fold greater than that of the labeled antigen. The cross-reactive (interspecies) antigens of every two viruses were selectively examined by precipitating the purified 125-I-labeled protein with antiserum against each of the other proteins. The extent to which these shared determinants were common to the other viruses was then tested by the effectiveness of the proteins of each virus to compete for antibody binding. Several classes of interspecies determinants were distinguished: those common to two of the groups of viruses, others to three, and some to all four. Moreover, an even greater variety of interspecies determinants was indicated by differences in the affinity of the individual proteins for antibody binding, supporting the hypothesis that there are at least several, if not many, different interspecies determinants with a broad spectrum of antigenic cross-reactivity. These studies suggest that the murine and feline viruses are closely related as they contain cross-reactive antigenic determinants not shared with the other viruses, that the feline virus is more closely related to the woolly monkey virus than to RD 114, and that the RD 114 and woolly monkey viruses retain interspecies determinants shared relatively equally with each of the other viruses.

Animals↗
PubMed1974

The viral envelope glycoprotein of murine leukemia virus and the pathogenesis of immune complex glomerulonephritis of New Zealand mice.

The use of monospecific antisera for the analysis by radioimmunoassay and immunofluorescence study of two major viral proteins, gp69/71 and p30 of murine leukemia virus, that could be of significance in the pathogenesis of immune complex glomerulonephritis of mice, particularly NZB and B/WF(1) hybrid mice, yielded the following conclusions. A remarkably high concentration of viral envelope glycoprotein, gp69/71, was detected in the spleen and serum of New Zealand mice (NZB, NZW, B/WF(1), and W/BF(1)); the concentration in the spleen was 10-fold greater than that found in AKR mice and 30-fold greater than that present in C57BL/6 mice. The gp69/71 was deposited along with bound immunoglobulins, apparently as an immune complex, in the diseased kidneys of mice, and the glomerular site and extent of deposition of gp69/71 was related to the severity of the glomerulonephritis. This study suggests that the pathogenesis of immune complex glomerulonephritis (and vasculitis) in mice is related to the expression of this specific viral envelope glycoprotein and to the host immune response to this protein.

Animals↗
PubMed1974

Murine sarcoma virus gene expression: transformants which express viral envelope glycoprotein in the absence of the major internal protein and infectious particles.

Expression of the major internal protein and the envelope glycoprotein of murine C-type viruses in focus-derived lines of normal rat kidney cells infected with Kirsten murine sarcoma virus was measured by radioimmunoassay. Of the clones selected, which do not produce virus particles or the major viral structural protein, approximately half express the viral envelope glycoprotein at concentrations found in productively infected cells. Expression of the envelope glycoprotein did not appear to alter significantly the properties of the transformed cells in culture.

Animals↗
PubMed1974

Host control of endogenous murine leukemia virus gene expression: concentrations of viral proteins in high and low leukemia mouse strains.

Two of the major molecular components of murine leukemia virus particles, the internal protein (p30) and the envelope glycoprotein (gp69/71) have been measured in the spleens of normal, 6- to 10-week-old mice of various inbred strains and crosses. Both proteins were detected in virtually all mice. Extracts of high leukemia, high murine leukemia virus strains (AKR, C58, PL) showed high levels of both proteins; extracts of other strains usually showed lower levels. Of particular interest, however, were the exceptions to these general observations: (1) Very little gp69/71 could be detected in spleens of BALB mice, and this trait was dominant in crosses with AKR and DBA/2, both of which express a high level of gp69/71. Thymus-deficient BALB/c-nu/nu (nude) mice, in contrast, showed a higher concentration of gp69/71 typical of other low leukemia strains, suggesting that the virtual absence of the protein in normal BALB/c mice may result from immunologic suppression. (2) With C57L, C57BL/10Sn, and C57BL/6 strains the concentration of p30 was lower, in some cases much lower, than would be expected from the concentration of gp69/71. (3) DBA/2 mice showed high levels of gp69/71, 10-fold greater than that of p30, whereas congenic DBA/2-Fv-1(b) mice showed the opposite pattern. (4) Mice of 129-G(IX) (-) strain showed no detectable levels of either p30 or gp69/71 proteins, although the congenic 129 (G(IX) (+)) showed appreciable levels of both. The absence of these proteins in 129-G(IX) (-) mice is a recessive trait, as F(1) hybrids with AKR and DBA/2 showed appropriate levels of both proteins. It is concluded that expression of viral p30 and gp69/71 proteins in mice is not coordinately linked and that expression is complex, being influenced by several genes, including Gv-1, H-2, Fv-1, and probably still others.

Animals↗
PubMed1974

Structural proteins of mammalian oncogenic RNA viruses: multiple antigenic determinants of the major internal protein and envelope glycoprotein.

The antigenic determinants of two purified protein constituents of mammalian C-type RNA viruses, the major structural protein of about 30,000 daltons, and the membrane glycopeptides of about 70,000 daltons were examined by competition radioimmunoassay. By the appropriate choice of antiserum and competing proteins, it was possible to distinguish type-specific, group-specific, and interspecies determinants. Both of the viral constituents were found to contain each of these three classes of antigens. The results suggested that the majority of the determinants of the major structural protein were group specific, 5% to 30% were interspecies, and a small fraction were type specific. In the case of the envelope glycopeptides, the chief determinants were type and group specific, and a small fraction were interspecies.

AKR murine leukemia virus↗
PubMed1974

Structural proteins of mammalian oncogenic RNA viruses: murine leukemia virus neutralization by antisera prepared against purified envelope glycoprotein.

Goat and rabbit antisera prepared against a purified Rauscher murine leukemia virus glycoprotein (gp69/71) rapidly neutralized spleen focus-forming virus in Rauscher and Friend virus preparations. Absorption studies revealed that most of the neutralizing activity of goat anti-Rauscher virus gp69/71 serum was directed against type- and group-specific determinants.

AKR murine leukemia virus↗
PubMed1974

Biological expression of antigenic determinants of murine leukemia virus proteins gp69-71 and p30.

Antisera to purified structural proteins of Rauscher murine leukemia virus, the major envelope glycoprotein, gp69/71, and the major internal protein, p30, were studied by immunofluorescence of viable and fixed virus-infected cells and by virus neutralization. Group-specific and type-specific determinants of gp69/71 were demonstrated by immunofluorescence and virus neutralization tests, indicating that these determinants are located in the cytoplasm and probably on the cell surface as well as on virus envelope. Antisera against p30 showed anti-group and anti-interspecies activities by immunofluorescence with no virus-neutralizing activity. Both antigenic determinants of gp69/71 were sensitive to guanidine-hydrochloride and to a lesser degree to ether treatment, whereas the group-specific determinants of p30 were relatively stable to these treatments.

AKR murine leukemia virus↗
PubMed1974

Structural proteins of mammalian oncogenic RNA viruses: immunological characterization of the p15 polypeptide of Rauscher murine virus.

The immunological properties of the purified 15,000-dalton protein of Rauscher murine type-C virus were analyzed by radioimmunoassay. The majority of the antigenic determinants of this protein were found to be remarkably specific to Rauscher and Friend virus and to a lesser extent to Moloney virus. Determinants reactive with other murine viruses (group-specific) or type-C viruses of other species (interspecies) were also demonstrated but were minor components of the total antigenic specificities of the protein. The results provide evidence that the antigenic properties of this protein specify the Friend-Moloney-Rauscher subgroup of type-C viruses.

Epitopes↗
PubMed1974

Type-C RNA virus gene expression in human tissue.

Partially purified fractions of human tissues have been analyzed by competition radioimmunoassay for the presence of two of the principle structural components of type-C RNA viruses, the major core protein (p27 to p30) and the major envelope glycopeptides (gp69/71). Screening of tissues was carried out by use of a heterologous assay system of (125)I-labeled Rauscher murine virus p30 antigen and anti-RD 114 virus serum which was found to detect a class of interspecies determinants common to murine, feline, and primate viruses. A competitor with the same apparent affinity for antibody binding as that of purified viral core proteins was found in relatively high concentration in tissues from patients with systemic lupus erythematosus, in some neoplastic tissues, and also in normal human tissues. This competitor from a lupus spleen chromatographed on phosphocellulose and showed size fractionation during gel filtration similar to known p27 to p30 viral proteins. An immunologically reactive protein was also demonstrated by immunodiffusion and by immunoprecipitation of (125)I-labeled human protein with anti-RD 114 p28 serum. Analysis of these human competitor proteins with homologous assay systems of viral core proteins and corresponding antisera showed that all, including the normal tissue extracts, appear similar to core proteins of known viruses, especially the RD 114 and woolly monkey species. A hypothesis suggested by these data is that many, if not all, humans harbor at least part of the genome of one or more type-C viruses, the properties of which are similar to those of viruses from other mammalian species, particularly primates.

Adenocarcinoma↗