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Biomedical subjects

J S Wolinsky

Publications and source records attributed to J S Wolinsky.

At least 109 records · Page 6Linked to original sources
PubMed1983

Conversion of nonfusing mumps virus infections to fusing infections by selective proteolysis of the HN glycoprotein.

Mumps virus strains differ in their ability to induce cell fusion following an infection: strains with active neuraminidase (NANase) fail to cause cell fusion, while strains with less active NANase cause cell fusion. When chymotrypsin is added to infected cells, cell fusion is amplified in a concentration-dependent manner for all mumps virus strains. Virions produced in such infections do not express HN glycoprotein-associated activities. Chymotrypsin treatment of purified mumps virus in vitro results in sequential cleavage of the HN glycoprotein without affecting F glycoprotein structure. Initially, HN is cleaved into two glycopolypeptides, HNc1 (32K) and HNc2' (41K), with concomitant loss of hemagglutinating and NANase activities, and infectivity. Further incubation with chymotrypsin causes complete degradation of HNc1 and digestion of HNc2' to HNc2 (13K-19K). Both HNc2' and HNc2 contain the [3H]palmitic acid label found in the HN polypeptide, which suggests that these fragments are associated with the viral membrane. Analyses of infected cells and released virions indicate that chymotrypsin acts similarly on HN exposed at the cell surface. Exogenous NANase does not abolish the protease-augmented cell fusion, though it does reduce cell fusion of untreated fusing strain infections. These results confirm that mumps virus HN glycoprotein is critically linked to cell fusion cytopathology and show that cryptic cell fusion activity in nonfusing strain infections can be unmasked by the proteolytic removal of the HN glycoprotein.

Animals↗
PubMed1983

Biosynthesis of mumps virus F glycoprotein: non-fusing strains efficiently cleave the F glycoprotein precursor.

Mumps virus infection of the CV-1 cell line results either in no cytopathic effect or extensive cell fusion, depending upon the infecting mumps virus strain. Growth cycle analyses indicated that both types of infection were the result of multiple cycle replication of mumps virus. Intracellular virus-specific polypeptide synthesis was examined by pulse- and pulse-chase-labelling with radioactive amino acids and sugars. The major polypeptides seen on SDS-polyacrylamide gels were NP (69 000 mol. wt.), P (45 000 mol. wt.) and M (40 000 mol. wt.); a non-structural polypeptide (22 000 mol. wt.) was also present in infected cell lysates. The HN (74 000 to 79 000 mol. wt.) glycopolypeptide was detected in [3H]glucosamine- and [3H]mannose-labelled infected cells. A 65 000 mol. wt. species that had incorporated these precursors was seen in pulse-labelled infected cell lysates, and this glycopolypeptide vanished during the chase interval with the concomitant appearance of two glycopolypeptides (59 000 mol. wt. and 14 000 to 15 000 mol. wt.) which represented the F1 and F2 subunits of the F glycoprotein. Immunological data confirmed the relatedness of the 65 000 mol. wt. glycopolypeptide to the F glycoprotein and identified it as the precursor F0. The F0 precursor glycopolypeptide was seen in cells infected with both fusing and non-fusing strains, and F0 was processed completely to F glycoprotein for all infections. Thus, the lack of cell fusion after infection with certain mumps strains is not the consequence of incomplete processing of the F0 precursor.

Animals↗
PubMed1983

Downbeat nystagmus. A case report of herpetic brain stem encephalitis.

A 35-year-old man with aplastic anemia developed prominent downbeat nystagmus 80 days after receiving an allogeneic bone marrow transplant. A diagnosis of herpes simplex encephalitis was made which was confirmed by positive virus cultures at autopsy 1 week later. Routine pathologic examination of the brain stem revealed no lesions which would explain the downbeat nystagmus. Immunoperoxidase studies, however, revealed virus-infected neurones throughout the brain stem including the nuclei of the basis pontis, the superior olive, and nuclei of the spinal tracts of 5 and 10. The significance of "negative" pathologic brain stem findings in cases of downbeat nystagmus is discussed.

Adult↗
PubMed1982

Hematogenous origin of the inflammatory response in acute poliomyelitis.

To determine the origin of the inflammatory response, and in particular the microglial rod cell response, in acute viral encephalitis, 4-week-old Swiss mice were injected with tritiated thymidine to label actively dividing cells prior to infection with the Lansing type 2 strain of poliovirus. As expected, the majority of polymorphonuclear and mononuclear leukocytes within the central nervous system perivascular infiltrates were shown to be hematogenous in origin. As early as 24 hours after infection, isotope-labeled cells having light histological and ultrastructural features consistent with microglia and microglial rod cells were identified within brain parenchyma and were shown to participate in neuronophagia and formation of glial nodules. Supraependymal and suprachoroidal cells were also shown to contain the label. However, neither endothelial cells nor pericytes contained label as determined by electron microscopy. These studies support a hematogenous origin for all cellular elements of the classic inflammatory response in viral infections of brain.

Animals↗
PubMed1982

Ross River virus-induced demyelination: I. Pathogenesis and histopathology.

Ross River virus (strain T48) infection in mice causes an encephalomyelitis characterized by focal, primary demyelination in the cerebellum, brain stem, and spinal cord. Maximal serum and brain content of virus occurs on days 2 and 4, respectively. Virus is not detectable in serum after day 3 or in brain after day 9. Histopathological lesions are present by day 2 and consist of perivascular macrophage and polymorphonuclear leukocyte infiltration, focal necrosis in the internal granule cell layer, and myelin disruption. Mononuclear cell infiltrates are present by day 5. Foci of demyelination in the presence of preserved axons become more widespread by day 8, and early partial remyelination occurs by day 13. Immunosuppression reduces the mononuclear cell infiltration but does not alter the demyelination . Although the mechanism of Ross River virus-induced demyelination is not known, these findings suggest that it is not immune mediated.

Animals↗
PubMed1982

Slow virus replication: the role of macrophages in the persistence and expression of visna viruses of sheep and goats.

Lentiviruses of sheep and goats cause slowly progressive diseases of the central nervous system (visna), lungs (maedi) and joints (arthritis) in their natural hosts. However, the virus target cell(s) in these diseases are still unknown. In this report, using laboratory-adapted Icelandic visna virus and several field strains recently obtained from sheep and goats with natural disease in the U.S.A., we show that macrophages became persistently infected when inoculated in culture. Furthermore, macrophages were an invariable source of virus from experimentally and naturally infected animals. Virus-producing macrophages developed minimal cytopathic changes and virus assembly occurred mainly intracellularly, accumulating in cytoplasmic vacuoles. In contrast to macrophages, sheep choroid plexus fibroblasts developed syncytial cytopathic changes after inoculation and virus maturation occurred at the cell surfaces. Replication of the Icelandic virus was highly productive in this system but that of the field viruses was very inefficient. In some cases these agents failed to replicate in the fibroblasts and no cytopathic effect occurred. This block in the field virus replication was, however, overcome when infected nonproducer fibroblasts were co-cultivated with macrophages. In these cases, virus production with attendant cytopathic effect in the fibroblasts required the continuous presence of macrophages because the cells reverted to a non-productive state when separated from macrophages and became productive again when subcultures were added to new macrophages. The roles of the macrophage as a virus target cell and virus inducer in the virus-macrophage-fibroblast interactions are discussed with inferences to the well-known phenomenon of restricted virus replication in infected animals and the immunopathological aspects of the diseases.

Animals↗
PubMed1982

Differentiation of mumps virus strains with monoclonal antibody to the HN glycoprotein.

A hybridoma cell line secreting antibody of the immunoglobulin G3 isotype with kappa light chains and with activity against the HN glycoprotein of the Kilham strain of mumps virus was established. The antibody exhibited structural homogeneity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had a microheterogeneous isoelectric spectrum characteristic of an antibody of monoclonal origin. The specificity of the monoclonal antibody, shown by immunoprecipitation performed with radiolabeled virus and infected cell lysates, was for the larger mumps virus glycoprotein. In functional assays the antibody inhibited the hemagglutinating and neuraminidase activities and neutralized the infectivity of the homologous Kilham strain of virus and clearly differentiated this strain from two heterologous strains, Enders and O'Take. The antibody was markedly less effective with the O'Take strain than with either the Kilham or Enders strain in inhibiting both hemagglutination and neuraminidase activity against the macromolecular substrate fetuin. The inhibition of the neuraminidase activity of the Kilham strain was independent of substrate size, the antibody inhibiting the hydrolysis of both fetuin and the trisaccharide neuraminlactose. By contrast, the antibody did not inhibit the hydrolysis of neuraminlactose by the two heterologous mumps strains. These results provide the first demonstration of antigenic differences between mumps virus strains and highlight the utility of monoclonal antibody in analyzing the structural basis underlying functional activities of the HN glycoproteins.

Antibodies, Monoclonal↗
PubMed1982

Rubella-specific immune complexes after congenital infection and vaccination.

Circulating immune complexes which contained rubella-specific immunoglobulins were detected in 21 out of 63 subjects with congenital rubella and in 39 out of 65 subjects vaccinated with attenuated rubella virus, but in none of 43 subjects susceptible to rubella or 87 subjects with remote naturally acquired immunity to rubella. The presence or level of circulating immune complexes and the presence of rubella-specific complexes did not correlate with conventional serum rubella hemagglutination inhibition antibody titers. In the group with congenital infection, the presence of specific complexes many years after birth was associated with late-emerging clinical problems involving several organ systems. In vaccinates, the presence of specific complexes was associated with a higher incidence of side reactions. Two-thirds of the vaccinates and all of those revaccinated showed specific immune complexes as late as 8 months after immunization.

Adolescent↗
PubMed1982

Postembedding immunocytochemical localization of paramyxovirus antigens by light and electron microscopy.

A postembedding method is described to localize antigens specific for various paramyxoviruses in sections of cells and tissues that have been fixed and embedded in epoxy resins for conventional electron microscopy. Viral antigens were localized in CV-1 cell cultures infected with simian virus 5 (SV5), brains of suckling hamsters inoculated with either neuroadapted mumps virus or hamster-adapted measles virus, and brains of adult mice infected with Sendai (parainfluenza I) virus. Both 1-micrometer-thick and thin (gold) tissue sections were etched with alcoholic sodium hydroxide-solution and then treated following either the unlabeled antibody peroxidase-antiperoxidase or the biotinylated protein A:avidin peroxidase procedure. Primary reagents included immunoglobulin isolated from hyperimmune rabbit sera with specificity to the major viral components of SV5 or SV5 hemagglutinin-neuraminidase, to whole mumps virus or mumps virus nucleocapsids, and to whole Sendai virus. Crude rabbit anti-Sendai virus antiserum and whole human subacute sclerosing panencephalitis (SSPE) sera were used in parallel. The results indicate that tissues processed for conventional evaluation by electron microscopy may be suitable, within limits, for postembedding immunocytochemical staining of paramyxovirus antigens.

Animals↗
PubMed1982

Immunochemical features of a case of progressive rubella panencephalitis.

Progressive rubella panencephalitis (PRP), a slowly progressive and fatal central nervous system (CNS) disorder due to rubella virus, is characterized by high cerebrospinal fluid (CSF) levels of immunoglobulins, oligoclonal bands and high CSF:serum rubella antibody titre ratios. Sera, CSF and neutral extracts of brain, spleen, lymph node and kidney obtained at autopsy from a case were analysed for immunoglobulin isotype and content by enzyme linked immunosorbent assays. Comparable titres of rubella specific IgA and IgG were found in sera and CSF, but accounted for a disproportionate amount of the isotype specific immunoglobulins of CSF (0.19%, 14.0%) as compared to serum (0.02%, 0.69%). The percentage of isotype specific immunoglobulins were not increased in extracts of most visceral tissues compared to serum, however, rubella specific IgA and IgG were disproportionately increased in extracts from most regions of brain sampled (1-60-fold and 8-27-fold respectively). No rubella specific IgM could be conclusively demonstrated in any specimen. Immunoprecipitation studies showed that the IgG reacted with the major glycoproteins (gp62, gp47-56 complex) and non-glycosylated polypeptide (p38) of radiolabelled rubella virions and infected cell lysates. These studies support the conclusion that a major portion of the rubella specific antibody is produced within the CNS of patients with PRP.

Antibodies, Viral↗
PubMed1981

Encephalitis after inhalation of measles virus: a pathogenetic study in hamsters.

A neuroadapted strain of measles virus (HNT) was administered by inhalation to newborn hamsters. Primary replication of virus in the lung was followed by the transient appearance of virus in spleen within 7 to 9 days of inoculation. A terminal encephalitis occurred between 6 and 60 days in 31% of infected hamsters, and virus was recovered by explant culture of these brains. Virus could not be cultured directly from brain or tissue homogenates. At least 7% of hamsters that had survived the infection for two months had antibody to measles virus. The histopathological change in morbid animals was limited to the central nervous system (CNS) and consisted of small foci of necrosis, perivascular mononuclear cell infiltrates, intracytoplasmic and intranuclear inclusions, and vacuolated pyknotic neurons. Immunofluorescent studies disclosed measles antigen in the lungs and brain. This hamster model of measles encephalitis following a "natural" route of inoculation appears to represent a faithful reproduction of certain CNS complications of natural measles infection in humans, i.e., measles encephalitis and subacute sclerosing panencephalitis.

Animals↗
PubMed1981

Characterization of immune complexes in progressive rubella panencephalitis.

In two patients with the slow virus disease progressive rubella panencephalitis, high levels of immune complexes were found in serum and, in one case, spinal fluid. These complexes contained immunoglobulin G. Serum complexes sedimented over a wide density range compared with the more homogeneous spinal fluid complexes. Complexes from both serum and spinal fluid contained antibody directed against rubella virus. Serum complexes were also shown to contain rubella antigen (or antigens) that appeared to differ between the two patients.

Adult↗