Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A number of ecotropic and xenotropic murine leukemia viruses were examined for their ability to induce the GIX antigen and Gross cell surface antigen (GCSA) in tissue culture fibroblasts. GIX appears to be a constituent of murine leukemia virus gp70; a molecular characterization of GCSA has not yet been reported. Antigen induction was measured by the ability of productively infected cells to absorb cytotoxic activity from the standard GIX- and GCSA-typing antisera. Cells infected by ecotropic viruses displayed four distinct phenotypes GIX:+/GCSA++, GIX-/GCSA++, GIX++/GCSA+, and GIX-/GSCA+; cells infected by xenotropic viruses were either GIX-/GCSA+ or GIX-/GCSA-. GIX induction appeared to be a type-specific property of some but not all Gross-AKR type ecotropic viruses. Differences in the degree of absorption of the GCSA antiserum by ecotropic virus- and xenotropic virus-infected cells indicated that GCSA may comprise multiple antigenic determinants.
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PMID:Induction of GIX antigen and gross cell surface antigen after infection by ecotropic and xenotropic murine leukemia viruses in vitro. 6 48

The expression of the major glycoprotein, gp71, of murine leukemia virus was studied on the surfaces of a variety of normal murine cell lines with a monospecific rabbit antiserum raised against purified Friend murine leukemia virus gp71. Using viable cell membrane immunofluorescence, most established and early passage normal murine cell lines were significantly reactive with the antiserum, irrespective of neoplastic transformation, strain genotype, or whether they were of embryonic or adult tissue origin. The only murine cells tested not detectably expressing gp71 determinants were BALB/3T3 lines. Although some Friend gp71 interspecies reactivity was discernible on normal murine cells, the principal reactivity was shown to be group specific. Fresh thymocytes from BALB/cJ (GIX-), C57BL/6J (GIX-), and 129/J (GIX+) mouse strains were also reactive with Friend gp71 antiserum, and this activity, as well as that of an antiserum prepared against purified AKR gp71, were also group specific. An activity discriminating GIX+ from GIX- thymocytes was not observed with either Friend or AKR gp71 antisera.
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PMID:Immunofluorescent analysis of expression of the RNA tumor virus major glycoprotein, gp71, on the surfaces of normal murine cells. 6 20

It is known that the thymocyte surface antigen GIX is found in some strains of mice and not others, and that its expression in mice of strain 129, in which most extensive genetic studies have been made, is controlled by two unlinked cellular chromosomal loci. We have now isolated a protein with a mol wt of approximately 70,000 daltons from the surface of thymocytes from 129 mice, which have antigenic and biochemical properties characteristic of the gp69/71 envelope component of murine leukemia virus. Our evidence is compatible with the conclusion that it carries the GIX antigen.
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PMID:Biochemical evidence linking the GIX thymocyte surface antigen to the gp69/71 envelope glycoprotein of murine leukemia virus. 16 85

Thymocytes of several mouse strains were tested for expression of the gp69/71 envelope component of murine leukemia virus by surface iodination, followed by immunoprecipitation and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Theses strains included two congenic lines differing from their partner stocks with respect to expression of GIX antigen demonstrable in the cytoxicity assay. We conclude that:(a) two structural variants of gp69/71 can be expressed on mouse thymocytes, (b) these are distinguishable by a small difference in mobility in SDS gels, (c) one carries GIX antigen and the other not, (d) they are coded, or their expression is regulated, by different chromosomal loci that are not closely linked, and (e) both can be expressed together on the thymocytes of inbred mice. In the intact thymocyte plasma membrane, the sites of group-specific antigen shared by the two gp69/71 variants, unlike the GIX type specificity carried by only one of them, are probably inaccessible to antibody.
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PMID:Expression of murine leukemia virus envelope glycoprotein gp69/71 on mouse thymocytes. Evidence for two structural variants distinguished by presence vs. absence of GIX antigen. 16 98

In a further genetic study of murine leukemia virus (MuLV) and its components we examined the backcross C57L X (C57L X AKR). This population was selected because strains AKR and C57L are both Fv-1n, and the restriction which the Fu-1b allele imposes on the output of virus was thereby obviated. The segregants were scored for three characters: (a) infectious Gross-AKR-type MuLV (V), in the tail; (b) group-specific antigen indicative of p30 internal viral protein, in spleen; and (c) GIX antigen, now thought to be indicative of gp69/71 viral envelope glycoprotein, on thymocytes. Our conclusions are: (a) It is confirmed that the AKR mouse has two unlinked chromosomal genes, Akv-1 and Akv-2, each of which can independently give rise to the life-long high output of MuLV that is characteristic of AKR mice. (b) Of the eight phenotypes that could possibly be derived from segregation of the three pairs of independent alternative traits, seven were observed, but on progeny testing only three were shown to reflect stably heritable genotypes; these were V+p30+GIX+ and V-p30-GIX- (the parental types) and V-p30+GIX+. A third, newly identified AKR gene, designated Akvp, segregating independently of Akv-1 and Akv-2, also determines expression of p30 and GIX but in this case independently of XC-detectable MuLV. (c) The four remaining observed phenotypes, which did not breed true on progeny testing, involved mostly antigen-negative parents yielding antigen-positive progeny; it is likely that these discrepancies represented suppression of phenotype by a maternal resistance factor.
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PMID:Relationship of infectious murine leukemia virus and virus-related antigens in genetic crosses between AKR and the Fv-1 compatible strain C57L. 17 87

Thymocytes from preleukemic AKR mice aged 5-6 mo have an altered pattern of cell surface antigens. The expression of four MuLV-related antigens on the cell surface (GIX, GCSA, gp70, p30) is markedly increased in comparison to 2-mo-old AKR mice and approximates the heightened levels of these antigens found on thymic leukemia cells. H-2 and Thy-1 alloantigens also show characteristic modifications in relation to age and leukemia development. In contrast to the high Thy-1/low H-2 levels on 2-mo-old AKR thymocytes, thymocytes from 6-mo-old mice and thymic leukemia cells frequently show a low Thy-1/high H-2 surface phenotype. As thymocytes from mouse strains with a low incidence of leukemia do not show these changes, they appear to represent a stage in the conversion of normal cells to leukemia cells.
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PMID:Age-related changes in cell surface antigens of preleukemic AKR thymocytes. 18 Feb 29

The GIX antigen expressed on the thymocytes of GIX+ mice is a type-specific constituent of glycoprotein gp70, which forms the major envelope component of murine leukemia virus. In the prototype GIX+ mouse strain 129, this glycoprotein is a Mendelian character expressed independently of virus production. In the intact thymocyte plasma membrane, part of this glycoprotein, bearing group-specific (gs) antigen, is inaccessible to antibody. The moiety bearing the type-specific GIX determinant is accessible to GIX antibody, which may be an important factor in determining the consequences of autoimmune responses involving GIX. Previously, all attempts to induce GIX antibody in mice had failed. We now find that the hybrid mouse (B6-GIX+ X 129) spontaneously produces substantial amounts of GIX antibody, presumably of the IgM class appearing as early as 2 mo of age. The specificity of the GIX natural mouse antibody is the same as that recognized by the conventional GIX typing serum produced in rats ("anti-NTD"). As neither parent strain produces appreciable GIX antibody, we surmise that this autoimmune response requires two dominant genes, each parent contributing a high-response allele to the hybrid. These can be envisaged as two immune response loci, controlling different immunocompetent cells which must cooperate to produce GIX antibody. Production of GIX antibody by the hybrids increases progressively with age. This is accompanied by decreased expression of GIX antigen on their thymocytes. We attribute this to antigenic modulation. Antibody to gs antigen of gp70 is also found in autoimmune (B6-GIX+ X 129) hybrids but not in either parent strain. We are investigating evidence of a pathological autoimmune syndrome in these hybrids. The special interest of this syndrome is that it presumably signifies the consequences of autoimmunization to a single C-type virus component, expressed without significant virus production, in a mouse with no evident genetic predisposition to such disease in the absence of that antigen.
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PMID:Spontaneous autoimmunization to GIX cell surface antigen in hybrid mice. 18 95

As background for a serological definition of the unique antigens of chemically induced sarcomas, we have typed a series of fibroblast and sarcoma cell lines of BALB/c and C57BL/6 origin by cytoxicity and absorption tests for murine leukemia virus (MuLV)-related cell surface antigens and known alloantigens. 7 of the 17 cultured lines expressed the range of cell surface antigens associated with MuLV (GIX, GCSA, gp70, p30), and this was invariably associated with MuLV production. In nonproducer lines of C57BL/6 (but not BALB/c) origin, a MuLV-gp70-like molecule was found on the surface of fibroblasts and sarcoma cells. The alloantigenic phenotype of these MuLV+ and MuLV- cell lines was H-2D+, H-2K+, Thy-1.2+ or -, PC.1+ or -, Lyt-1.2-, Lyt-2.2-, Ia.7-, and TL.2-. A unique antigen was defined on the BALB/c ascites sarcoma Meth A with antisera prepared in BALB/c or (BALB/c X C57BL/6)F1 mice. Tissue culture lines derived from this tumor were MuLV-, which facilitated serological study of the antigen. Absorption analysis indicated that the antigen was restricted to Meth A; it could not be detected in normal or fetal BALB/c tissue MuLV+ or MuLV- fibroblast lines, 12 syngeneic or allogeneic sarcomas, or normal lymphoid cells from 13 different inbred mouse strains.
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PMID:Cell surface antigens of chemically induced sarcomas of the mouse. I. Murine leukemia virus-related antigens and alloantigens on cultured fibroblasts and sarcoma cells: description of a unique antigen on BALB/c Meth A sarcoma. 19 92

We have analyzed large RNase T1-resistant oligonucleotides derived from the genomes of 16 recombinants between N- and B-tropic murine leukemia viruses of BALB/c. The parental viruses, designated SP-N and LP-B, differ in several phenotypic or biochemically defined properties: N- or B-tropism; XC plaque morphology, electrophoretic mobility of three virion proteins (p15, p30, and gp70); ability to induce GIX antigen on infected cells; presence of 6 to 8 (out of 36 to 38 analyzable) large T1 oligonucleotides. One SP-N-specific T1 oligonucleotide was inherited by all 16 N-tropic recombinants and, thus, appears to be linked to N-tropism. This oligonucleotide lies in the 5' third of the oligonucleotide map of SP-N. One LP-B-specific T1 oligonucleotide was inherited by all 11 recombinants whose gp70 has an electrophoretic mobility like that of LP-B gp70 and that, like LP-B, fail to induce GIX antigen. This oligonucleotide lies in the 3' third of the oligonucleotide map of LP-B.
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PMID:T1 oligonucleotides that segregate with tropism and with properties of gp70 in recombinants between N- and B-tropic murine leukemia viruses. 20 22

Murine leukemia virus-related RNA species were examined in a set of radiation-induced T-cell leukemias from BALB/c mice. No evidence was found for linkage of viral long terminal repeat-derived (U5) sequences to information of host origin. A novel class of 2-kilobase (kb) env-related transcripts, about 1kb shorter than normal viral env messenger, was found in all the leukemias. All of the 2-kb transcripts contained sequences homologous to the xenotropic virus-related env sequences in the Friend spleen focus-forming virus, representing the N-terminal portion of gp70. In two of the leukemias, these transcripts were found to contain both ecotropic p15E and U3 sequences in addition to the xenotropic gp70-related sequence. These two leukemias, but not others in which ecotropic sequences were absent from the 2-kb RNA, harbored several copies of a specific class of env recombinant proviruses. These proviruses possessed full-size env genes and were submethylated, as shown by SmaI and XmaI digests of proviral DNA. Low levels of 2-kb RNA were found in normal thymocytes from strains BALB/c, AKR, and 129 but not from congenic 129 GIX- mice. It is possible that the 2-kb RNA may originate by a novel splicing step that removes portions of the gp70 and p15E sequences from full-length env transcripts.
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PMID:Evidence for a new form of retroviral env transcript in leukemic and normal mouse lymphoid cells. 619 84


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