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Biomedical subjects

O Haller

Publications and source records attributed to O Haller.

At least 73 records · Page 4Linked to original sources

Antibody to mouse interferon alpha/beta abrogates resistance to the multiplication of Friend erythroleukemia cells in the livers of allogeneic mice.

Friend erythroleukemia cells (FLC) (H-2d) injected intravenously into adult syngeneic DBA/2 or allogeneic C57B1/6 (H-2b) or C3H (H-2k) mice lodge in the liver but only multiply in the liver of syngeneic mice. Our results indicated that endogenous IFN-alpha/beta was a crucial factor in preventing the multiplication of FLC in the liver of adult allogeneic mice. (a) Treatment of allogeneic adult C57B1/6 or C3H mice with polyclonal antibody to mouse IFN-alpha/beta (but not antibody to IFN-gamma) completely abrogated the resistance to the multiplication of FLC in the liver and 87% of tumor-injected, antibody-treated C57B1/6 mice died with extensive tumor involvement of the liver. In contrast, after intravenous inoculation FLC do not multiply at all (or very rarely) in the liver of adult C57B1/6 mice left untreated or treated with a variety of control globulins, and no deaths occurred. (b) 8 h after intravenous inoculation of FLC, poly(A)+ RNA hybridizable with specific DNA probes for mouse IFN-alpha or -beta (but not -gamma) was present in the liver of injected C57B1/6 mice. Using the expression of the Mx protein as an indicator of the presence of IFN-alpha/beta, we showed that Mx+ congenic C57B1/6 mice injected with FLC exhibited a marked increase in the expression of the Mx protein in the liver, spleen, kidney and lung, and this increase was blocked by treatment of mice with antibody to IFN-alpha/beta. The possibility that different host mechanisms are elicited depending on the site of tumor growth in allogeneic mice is discussed. IFN-alpha/beta appears to be of particular importance in determining the resistance of the liver to FLC in allogeneic mice.

Age Factors↗

Antiviral state against influenza virus neutralized by microinjection of antibodies to interferon-induced Mx proteins.

In mouse Mx+ cells, interferon alpha/beta induces the synthesis of the nuclear Mx protein, whose accumulation is correlated with specific inhibition of influenza viral protein synthesis. When Mx+ mouse cells are microinjected with the monoclonal anti-Mx antibody 2C12, interferon alpha/beta still induces Mx protein, but no longer inhibits efficiently the expression of influenza viral proteins as visualized by immunofluorescent labeling. However, interferon inhibition of an unrelated control virus, vesicular stomatitis virus, remains unchanged. Proteins with homology to mouse Mx protein are found in interferon-treated cells of a variety of mammalian species. In rat cells, for instance, rat interferon alpha/beta induces three Mx proteins which all cross-react with antibody 2C12 but differ in mol. wt and intracellular location, and it protects these cells well against influenza viruses. However, when rat cells are microinjected with antibody 2C12, interferon alpha/beta cannot induce an efficient antiviral state against influenza virus infection, whereas protection against vesicular stomatitis virus is not altered. These results show that both mouse and rat cells require functional Mx proteins for efficient protection against influenza virus. They further demonstrate that microinjection of antibodies is a promising way of elucidating the role of particular interferon-induced proteins in the intact cell.

Animals↗

Genetic mapping of the Mx influenza virus resistance gene within the region of mouse chromosome 16 that is homologous to human chromosome 21.

A total of 318 progeny from four backcrosses involving different laboratory strains and subspecies of Mus musculus were analyzed to map the Mx gene to the region of mouse chromosome 16 (MMU 16) which is homologous to human chromosome 21 (HSA 21). This result suggests that Mx will be found in the region of HSA 21 which has been implicated in Down syndrome when inherited in three copies.

Animals↗

A family of interferon-induced Mx-related mRNAs encodes cytoplasmic and nuclear proteins in rat cells.

Mouse Mx protein, an interferon (IFN)-induced nuclear protein, confers selective resistance to influenza virus. We show here that, as with influenza virus-resistant Mx+ mouse embryo cells, influenza virus mRNA accumulation and protein synthesis are strongly inhibited in rat embryo cells treated with IFN-alpha/beta. IFN-alpha/beta induced in rat cells the synthesis of Mx-related mRNAs migrating on Northern (RNA) gels as two bands of about 3.5 and 2.5 kilobases which directed the synthesis of three electrophoretically distinct proteins called rat Mx proteins 1, 2, and 3. The three rat proteins were antigenically related to the mouse Mx protein but differed in molecular weight and intracellular location. Rat Mx protein 1 was found predominantly in the nucleus and, on the basis of several criteria, resembled the nuclear mouse Mx protein. It was induced by IFN-alpha/beta in all 28 inbred rat strains tested. Rat Mx proteins 2 and 3 differed from protein 1 at the carboxy terminus and were predominantly cytoplasmic like the human Mx homolog. Sequence data of partial cDNA clones indicate that three Mx-related genes, rather than one, exist in the rat.

Animals↗

Influenza virus-susceptible mice carry Mx genes with a large deletion or a nonsense mutation.

The interferon-regulated mouse Mx gene encodes the 72-kilodalton nuclear Mx protein that selectively inhibits influenza virus replication. Mice carrying Mx+ alleles synthesize Mx protein and resist influenza virus infection, whereas mice homozygous for Mx- alleles fail to synthesize Mx protein and, as a consequence, are influenza virus susceptible. Southern blot analysis allowed us to define the following three distinct Mx restriction fragment length polymorphism (RFLP) types among classical inbred strains: RFLP type 1 in the Mx+ strains A2G and SL/NiA, RFLP type 2 in BALB/c and 33 other Mx- strains, and RFLP type 3 in CBA/J and 2 other Mx- strains. cDNA clones of Mx mRNAs from BALB/c and CBA/J cells were isolated, and their sequences were compared with that of the wild-type Mx mRNA of strain A2G. Mx mRNA of BALB/c mice has 424 nucleotides absent from the coding region, resulting in a frame shift and premature termination of Mx protein. The missing sequences correspond exactly to Mx exons 9 through 11. These three exons, together with some flanking intron sequences, are deleted from the genomes of all Mx RFLP type 2 strains. The Mx- phenotype of the Mx RFLP type 3 strain CBA/J is due to a point mutation that converts the lysine codon in position 389 to a termination codon. Mx RFLP type 3 strains have an extra HindIII site which maps to an intron and thus probably does not affect the coding capacity of Mx mRNA. We further show that the Mx mRNA levels in interferon-treated BALB/c and CBA/J cells are about 15-fold lower than in similarly treated Mx+ cells. This is probably due to decreased metabolic stabilities of the mutant mRNAs.

Animals↗

Influenza virus resistance of wild mice: wild-type and mutant Mx alleles occur at comparable frequencies.

The laboratory-reared progeny of wild Mus musculus domesticus from several places in Europe and from California were tested for resistance to experimental infection with influenza viruses and for the ability of their explanted macrophages to synthesize Mx protein in response to type I interferon. About 75% of these mice were resistant to influenza viruses and were able to synthesize Mx protein, as expected for mice carrying the influenza virus resistance allele Mx+ in either homozygous or heterozygous form. Resistance of wild mice was inherited as a single autosomal dominant trait which cosegregated with the ability to synthesize Mx protein. About 25% of the randomly bred wild mice failed to synthesize Mx protein and died after infection with influenza virus, very much like inbred mice homozygous for the Mx- allele. We conclude that Mx+ and Mx- alleles occur at roughly equal frequencies in wild mice and that some selective advantage for heterozygous individuals exists in the wild. This finding raises new questions about the physiological role of the Mx locus.

Animals↗

Mx protein: constitutive expression in 3T3 cells transformed with cloned Mx cDNA confers selective resistance to influenza virus.

Mx+ mice are much more resistant to influenza virus than Mx- strains. The resistance is mediated by interferon (IFN) alpha/beta. After IFN treatment, Mx+ but not Mx- cells accumulate Mx protein and become specifically resistant to orthomyxoviruses. cDNA encoding Mx protein was cloned and sequenced. Southern analyses indicate that Mx- alleles derive from their Mx+ counterpart by deletions. IFN-treated Mx+ cells contained a 3.5 kb Mx mRNA, while Mx- cells showed only traces of shorter Mx RNA. Mx- cells transformed with Mx cDNA expressed Mx protein constitutively to varying extents; resistance of individual cells to influenza virus correlated with Mx protein expression. Thus, specific resistance to influenza virus in vivo may be attributed to Mx protein expression and is independent of other IFN-mediated effects.

Amino Acid Sequence↗

Interferon-regulated influenza virus resistance gene Mx is localized on mouse chromosome 16.

Genomic Southern blots of mouse-hamster somatic cell hybrids were analyzed with a probe prepared from a cDNA encoding murine Mx protein, the product of the interferon-regulated influenza virus resistance allele Mx+. Results of this analysis indicate that the Mx gene is located on mouse chromosome 16. In appropriate backcross mice, no linkage was observed between Mx and md, a marker previously mapped close to the centromere of chromosome 16, suggesting a more distal localization of Mx.

Alleles↗

Transcriptional activation of the mouse Mx gene by type I interferon.

Mouse cells of the Mx+ genotype accumulate Mx mRNA in response to type I interferon (IFN). Nuclear runoff experiments show that IFN stringently regulates Mx gene expression at the level of transcription. Mx mRNA synthesis peaks about 3 h after IFN treatment, and within 5 h, Mx mRNA concentration rises from undetectable levels to about 0.1% of polyadenylated RNA.

Animals↗

[Prevalence of antibodies against HTLV-III in various regions in Switzerland].

Acquired immune deficiency syndrome (AIDS) has been etiologically linked with the human T-cell lymphotropic virus HTLV-III. In a study on the prevalence of antibodies to this virus in Switzerland, sera from 941 individuals were collected in 5 major urban areas (Basel, Berne, Geneva, Lausanne and Zurich) in 1983 and 1984. All sera were tested by ELISA and the majority also by Western blot. We found an antibody prevalence of 100% among 22 cases of AIDS, of 94% among 48 cases of AIDS-related complex (ARC), and of 57% among 14 homosexual contacts of AIDS patients. Among 55 sera collected from i.v. drug addicts in 1984, 53% were positive, whereas the rate had been 36% among 103 sera collected in 1983. The rate was 19% among 227 sera collected from asymptomatic active homosexuals in 1984, against 10% among 40 sera collected in 1983. 8% positives were found among 98 patients with various types of viral hepatitis. In addition, 4% of 84 sera of individuals from Equatorial Africa were positive. No positives were found among 15 sera of individuals from other African regions, among 32 sera of persons from various regions of Asia, and among 203 Swiss blood donors. These results demonstrate the high and increasing rate of HTLV-III infection among groups at risk for AIDS, and suggest that HTLV-III-related diseases will be a serious problem in the years ahead.

Acquired Immunodeficiency Syndrome↗

Polyclonal and monoclonal antibodies to the interferon-inducible protein Mx of influenza virus-resistant mice.

Interferon-alpha/beta induces in cells from mice carrying the influenza virus resistance allele Mx+ the synthesis of a unique 75,000-dalton protein (designated here protein Mx) that was not detectable in interferon-treated cells from Mx- mice lacking the resistance allele (Horisberger, M. A., Staeheli, P., and Haller, O. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 1910-1914). We have immunized Mx- BALB/c mice with extracts of interferon-treated cells from congenic Mx+ BALB X A2G-Mx mice. Resulting hyperimmune sera immunoprecipitated a single interferon-inducible 75,000-dalton protein of Mx+ embryo cells. Sera did not react with any interferon-inducible protein of Mx- cells. Synthesis of the immunoprecipitable 75,000-dalton protein Mx was induced by interferon-alpha/beta but not by interferon-gamma in Mx+ cells of diverse genetic backgrounds. Monoclonal antibodies to protein Mx were selected in similar immunoprecipitation assays. One discrete in vitro translation product of relevant mRNA reacted with polyclonal and monoclonal antibodies and was indistinguishable from in vivo synthesized protein Mx.

Animals↗

Antibodies to HTLV-III in Swiss patients with AIDS and pre-AIDS and in groups at risk for AIDS.

We tested serum samples from Swiss subjects by three different assays based on enzyme-linked immunosorbent assay (ELISA) and Western blot techniques for antibodies to proteins associated with the recently discovered human T-cell leukemia/lymphoma virus HTLV-III, the putative etiologic agent for the acquired immunodeficiency syndrome (AIDS). Of 10 patients with AIDS and 10 with pre-AIDS, all were antibody-positive. Furthermore, 37 of 103 intravenous-drug addicts (36 per cent), 4 of 40 healthy homosexual men (10 per cent), 7 of 83 patients with various types of hepatitis (8.4 per cent), but none of 83 healthy blood donors or 10 other controls were antibody-positive. Antibodies to the major viral protein p24 were found consistently and at high titers in the seropositive members of the groups at risk and in those with pre-AIDS but were dramatically reduced in patients with AIDS. In contrast, antibodies to another virus-associated protein, p41, were present in all cases of AIDS and pre-AIDS but were absent in nearly 10 per cent of seropositive persons at risk. Whereas p41 and p24 thus appear to be the targets of choice for future screening tests, the ELISA test that is currently available is a useful screening tool.

Acquired Immunodeficiency Syndrome↗

Interferon-induced protein Mx accumulates in nuclei of mouse cells expressing resistance to influenza viruses.

In mouse cells carrying the dominant influenza resistance allele Mx+ (but not in Mx- cells) interferon-alpha/beta (IFN) induces an efficient antiviral state against influenza viruses and, concomitantly, the synthesis of a 75,000-Da protein (protein Mx). Here, indirect immunofluorescence using monoclonal antibodies was used to demonstrate that protein Mx accumulates in the nucleus of IFN-treated Mx+ cells, suggesting a nuclear site of action. Protein Mx is present in the nucleus of untreated influenza virus-resistant macrophages freshly explanted from the peritoneal cavity of Mx+ mice but is lost with time in culture when peritoneal macrophages become permissive for influenza virus.

Alleles↗

Localization of the gene for the vitamin B12 binding protein, transcobalamin II, near the centromere on mouse chromosome 11, linked with the hemoglobin alpha-chain locus.

Somatic cell hybrids, recombinant inbred (RI) mouse strains, and backcross breeding experiments were used to locate the gene of transcobalamin II (Tcn-2), the vitamin B12 binding protein in mouse serum. TCN-2 was found to be useful genetic marker in the somatic cell hybrids. Selected hybrid clones were derived from fusions between GR mouse cells and the Chinese hamster cell line E36. Analysis of mouse specific chromosomal enzyme markers in relationship to TCN-2 secretion, in the hybrid clones, provided provisional evidence for assignment of the Tcn-2 locus to chromosome 11. The strain distribution pattern of the TCN-2 variants S and F in the RI series CXS, constructed from the cross of BALB/cHeA (TCN-2S) with STS/A (TCN-2F), implied a close linkage with the hemoglobin alpha-chain locus (Hba) on chromosome 11. Backcross breeding using inbred strains confirmed these findings and located the Tcn-2 gene closest to the centromere, linked with waved 2 (wa-2) and Hba with recombination frequencies of 6.9 and 19.2% each. The linkage group Tcn-2/wa-2/Hba was established.

Animals↗

Interferon-induced guanylate-binding proteins: mapping of the murine Gbp-1 locus to chromosome 3.

GBP-1 is the predominant species of a family of guanylate-binding proteins synthesized in mouse cells in response to interferons (IFNs) alpha, beta, or gamma. IFN inducibility of this 65,000-Da protein is controlled by alleles at a single autosomal locus, Gbp-1, with allele a encoding inducibility and allele b noninducibility. Here, we present evidence suggesting that both alleles occur in outbred populations of wild mice. Using recombinant inbred strains and classical linkage analysis of offspring of two-point and three-point backcrosses we demonstrate that Gbp-1 is linked to Adh-3 (encoding alcohol dehydrogenase C2) and VaJ (varitintwaddler-Jackson) located on the distal part of chromosome 3. The relevant recombination frequencies (RFs) (+/- SE) were 3.5 (+/- 1.1) and 11.7 (+/- 2.8)%, respectively. We further show that strain B6.C-H-23c/By(HW 53), congenic for a small segment of chromosome 3, carries the BALB/c alleles at both the Gbp-1 and the Adh-3 locus and not the alleles of the B6 background strain confirming the chromosomal location and close linkage of the two loci.

Animals↗

Inhibition of influenza viral mRNA synthesis in cells expressing the interferon-induced Mx gene product.

Interferons alpha and beta induce an efficient antiviral state against influenza virus in mouse cells that possess the Mx gene, but not in mouse cells that lack this gene. In Mx-containing cells treated with interferon the amount of viral mRNA synthesized as a result of primary transcription is drastically reduced. Only two viral mRNAs could be detected by Northern analysis and by translating the poly(A)+ RNA from infected cells in wheat germ extracts: a reduced amount of the mRNA for nonstructural protein 1 and an even lower amount of the mRNA for the matrix protein. The other viral mRNAs were not made in detectable amounts. In addition, the rate of viral mRNA synthesis catalyzed by the inoculum transcriptase, measured by in vitro RNA synthesis catalyzed by permeabilized cells, was severely inhibited. In contrast, interferon treatment of cells lacking the Mx gene had little or no effect on either the steady-state level or the rate of synthesis of viral mRNAs made by the inoculum transcriptase. These results indicate that the interferon-induced Mx gene product, a 75,000-molecular-weight protein that accumulates in the nucleus, inhibits influenza viral mRNA synthesis which occurs in the nucleus. No Mx-specific effect acting directly on viral protein synthesis in the cytoplasm was observed.

Animals↗