Extracellular release of enveloped vaccinia virus from mouse nasal epithelial cells in vivo.

The release of vaccinia virus from mouse nasal epithelial cells infected in vivo was studied by electron microscopy. Intracellular naked vaccinia virus was enwrapped by Golgi membranes to form a double membrane intermediate. The outer membrane of the intermediate presumably fused with the plasma membrane, releasing extracellular enveloped virus.

Developmental disturbances in the hamster retina caused by a mutant of mumps virus.

Newborn hamsters were inoculated intracerebrally with either the neurovirulent Kilham strain of mumps virus or a mutant (M13) strain of this virus. The M13 strain has an alteration in the haemagglutinin-neuraminidase protein of its envelope and causes a low-grade infection of the brain. Both strains spread consistently to the retina where the Kilham strain caused an extensive necrotizing infection.

The effects of monoclonal antibodies against the hemagglutinin-neuraminidase and fusion protein on the release of Sendai virus from infected cells.

Vero cell cultures in Leighton tubes were infected with egg-grown Sendai virus at high multiplicity of infection. Four hours after infection, the cultures were labelled with 35S-methionine, after which various concentrations of fourteen and five mouse monoclonal antibodies directed against different antigenic determinants of the hemagglutinin-neuraminidase (HN) and fusion (F) protein, respectively, were added to the medium. Fourty-eight hours after infection radiolabelled virions released into the medium were collected and purified by discontinuous sucrose gradient centrifugations.

Hemagglutinin-neuraminidase glycoprotein as a determinant of pathogenicity in mumps virus hamster encephalitis: analysis of mutants selected with monoclonal antibodies.

With the aid of monoclonal antibodies directed against a specific site on the hemagglutinin-neuraminidase surface glycoprotein, four mutants of the Kilham neurotropic strain of mumps virus were isolated. All four mutants had increased neuraminidase activity. Two mutants (M10 and M12) lost their hemagglutination capacity with human O erythrocytes but retained their ability to agglutinate guinea pig erythrocytes at 4 degrees C.

Dynamics of Ia-expressing cells and T lymphocytes of different subsets during experimental allergic neuritis in Lewis rats.

Inflammatory cells were characterized by immunohistochemistry, utilizing monoclonal antibodies against cell surface antigens in frozen sections of sciatic nerves and nerve roots of Lewis rats, sacrificed during the course of experimental allergic neuritis. Large numbers of Ia-expressing irregular macrophage-like/dendritic cells, as well as W 3/13 reactive T lymphocytes of both W 3/25 reactive helper and ox8 reactive suppressor/cytotoxic phenotypes were seen within afflicted peripheral nervous tissue at the start of clinical symptoms and at the height of the disease. T lymphocytes of both helper and suppressor/cytotoxic phenotypes decreased concomitant with clinical recovery.

IgM and IgG responses during chronic relapsing experimental allergic encephalomyelitis (r-EAE).

During chronic relapsing experimental allergic encephalomyelitis (r-EAE) in guinea pigs, serum IgM and IgG concentrations increased markedly early in disease. Serum IgM and IgG increased similarly in control animals immunized with Freund's incomplete adjuvant (FIA) and Mycobacterium tuberculosis (MT). In the chronic phase of r-EAE but not in control animals, elevated IgM was also found in central nervous system (CNS) extracts, suggesting intrathecal IgM synthesis.

Asymmetric budding of viruses in ependymal and choroid plexus epithelial cells.

Sendai virus injected intracerebrally into 3-week-old mice caused infection of ependymal and choroid plexus epithelial cells. Budding of mature viruses occurred only from the apical surfaces of these cells. The viral peplomere proteins, haemagglutinin-neuraminidase and fusion, were concentrated on the apical portion of the ependymal cells, while the nucleocapsid-associated polymerase protein was dispersed throughout the cytoplasm.

Mumps virus infection of the developing mouse brain--appearance of structural virus proteins demonstrated with monoclonal antibodies.

Newborn mice and hamsters were inoculated intracerebrally with mumps virus strains of high and low neurovirulence, Kilham and RW, respectively and with an egg-adapted patient isolate. The presence of viral antigen in brain tissue was analyzed with the immunofluorescence technique employing monoclonal antibodies against nucleoprotein (NP), polymerase (P), matrix (M), hemagglutinin-neuraminidase (HN) and fusion (F) mumps virus components. As expected, hamsters developed a fatal encephalitis eight to nine days after infection with the Kilham strain and synthesis of all five structural viral antigens was identified.

Sendai virus infection in the mouse brain: virus spread and long-term effects.

Following intranasal instillation of Sendai virus in newborn mice an extensive virus infection of respiratory epithelium and olfactory mucosa was observed by immunoperoxidase technique. Viral antigen appeared in olfactory nerves and in neurons of the trigeminal ganglia. Selective labeling of neurons in trigeminal ganglia was also seen after virus injection into the snout.

Uptake and transport of herpes simplex virus in neurites of rat dorsal root ganglia cells in culture.

Attachment and neuritic transport of herpes simplex virus (HSV) type 1 (McIntyre) were studied in a cell culture system with dissociated cells of rat dorsal root ganglia. The two-chamber cell culture system containing a diffusion barrier penetrated by neurites of cultured sensory neurons permitted infection of neurites extending outside the diffusion barrier without exposure of the neuronal cell soma. HSV adsorbed to neuritic extensions and reached the neuronal soma within 1.

Herpes simplex virus-induced demyelination. Effects of reinfection and challenge with neuroantigens.

Mice injected into the snout with the F-strain of herpes simplex virus (HSV) showed demyelination in the central part of the trigeminal root and brainstem. In this well characterized model the effect of reinfection with a virulent strain of HSV, and of immunization with UV-light-inactivated HSV and neuroantigens were examined. A marked enhancement of demyelination was found in mice immunized with spinal cord extracts in Freund's adjuvant prior to the HSV infection.

Cellular localization of five structural proteins of Sendai virus studied with peroxidase-labelled Fab fragments of monoclonal antibodies.

By the use of horseradish peroxidase-labelled Fab fragments of monoclonal antibodies, five major structural components of Sendai virus, namely the nucleocapsid (NP), polymerase (P), matrix (M), fusion (F), and haemagglutinin-neuraminidase (HN) proteins were localized in infected Vero cells. The P and NP proteins were found in association with large clusters of ribosome-like particles and nucleocapsids in the cell cytoplasm. They were not concentrated at the cytoplasmic membrane, except in nucleocapsids within budding viral particles.

Sendai virus infection in the brains of mice: distribution of viral antigens studied with monoclonal antibodies.

Newborn and 12- and 21-day-old mice were inoculated intracerebrally with Sendai virus. Titers of infectious virus peaked on days 1-2 after infection and had disappeared after three days in 12- and 21-day-old mice and six days in newborn mice. The levels of infectious virus in the brain declined before the appearance of serum antibodies, which in newborn mice was delayed until day 12.

Neuroaxonal dystrophy in childhood. Report of two second cousins with Hallerworden-Spatz disease, and a case of Seitelberger's disease.

Three late infantile cases of neuroaxonal dystrophy are presented, two of them second cousins with Hallerworden-Spatz disease and one sporadic case with Seitelberger's disease. At about 1 1/2 years of age the patients with Hallerworden-Spatz disease developed clinical signs including progressive extrapyramidal motor disorder and mental retardation. They died at 8 and 11 years.

Demonstration of serum IgG antibodies against myelin during the course of relapsing experimental allergic encephalomyelitis in guinea pigs.

Chronic relapsing allergic encephalomyelitis (r-EAE) was induced in a local strain of guinea pigs. By the use of isoelectric focusing (IF) followed by antigen immunofixation and autoradiography, antibodies directed against central nervous system (CNS) myelin were detected in 21 of 23 sera sampled during the course of r-EAE. Previous absorption of the sera with CNS myelin reduced or abolished antibody activity on autoradiograms.

Neuron to neuron transmission of herpes simplex virus. Transport of virus from skin to brainstem nuclei.

Herpes simplex virus (HSV) injection into the snout of mice was followed by the appearance of HSV antigen in neurons in trigeminal ganglia, main sensory and spinal tract trigeminal nuclei, reticular formation including raphe nuclei and locus ceruleus on both sides. The findings indicate that HSV spreads via axons, passes through a series of neurons and in this way can reach vital nuclei in the brainstem including monoaminergic neurons from the primary replication area in the lip.

Effect of glycosylation inhibitors on the release of enveloped vaccinia virus.

Addition of 1 to 10 mM 2-deoxy-D-glucose (2-dg) or glucosamine (gln) to the growth medium of vaccinia virus-infected cells inhibited the release of extracellular enveloped vaccinia virus (EEV) without affecting the production of intracellular naked vaccinia virus (INV) particles. In contrast, INV infectivity (particles per PFU) was decreased sevenfold by 50 mM 2-dg. Treatment with 2-dg reduced but did not eliminate glycosylation of the INV 37,000-molecular-weight glycoprotein.

Virus-induced demyelination in herpes simplex virus-infected mice.

Herpes simplex virus (HSV) infection of the mouse trigeminal ganglia and the brain stem is associated with demyelination of axons in the central part of the trigeminal root and inflammatory cell infiltration and perivascular demyelination in the brain stem. Cyclophosphamide (CPA) treatment prior to or soon after HSV inoculation caused increased axonal spread of infective virus from the peripheral site of inoculation, more widespread and severe demyelination and increased mortality, suggesting that by CPA the virus invasion of the CNS was facilitated. A direct cytocidal effect of HSV on myelinating cells seemed one plausible explanation for the demyelination.

The effect of cytochalasin D and monensin on enveloped vaccinia virus release.

Both monensin and cytochalasin D reduced the production of infectious cell associated virus and infectious extracellular virus with the latter clearly being the more sensitive. The difference in yields were even more clearly seen if the yield of virus particles was monitored instead of yield of infectious virus. Addition of 1 microgram/ml cytochalasin D or 1 microM monensin to the growth medium of vaccinia virus-infected cells inhibited the appearance of extracellular enveloped vaccinia virus (EEV) in the growth medium without affecting the production of intracellular naked vaccinia virus (INV) particles.

Somatopetal axonal transport of fluorescent lectins: distribution pattern and cytophotometric quantification in mouse peripheral neurons.

Six FITC-labeled lectins (Con A, WGA, SBA, DBA, UeA 1, PNA) with different carbohydrate specificities were injected into the snout region of 12-day-old mice. WGA, and to a lesser extent Con A, accumulated in trigeminal and facial neurons as a result of somatopetal axonal transport. Only an occasional trigeminal neuron was labeled after injection of SBA and DBA.

Neuronal uptake of iron: somatopetal axonal transport and fate of cationized and native ferritin, and iron-dextran after intramuscular injections.

Mice were injected into the muscles of the vibrissae with native ferritin (NF), cationized ferritin (CF) and iron-dextran. CF adsorbed on to the surface of the axon terminal at the neuromuscular junction, while NF did not. Both CF and NF were incorporated into vesicles and vacuoles at the synapse, but CF uptake was detected after injections at much lower concentrations than NF.

Toxicity and neuronal transport of stable liposomes and phospholipid in the nervous system.

When unilamellar "stable" liposomes composed of a dialkyl analog of phosphatidylcholine, tetradecyloctadec-11-eno(1)phosphocholine (dialkyl-PC), plus cholesterol at 1:1 molar ratio, and a trace of [3H]dialkyl-PC were injected into the vitreous of the rabbit eye, macrophage infiltration and phagocytosis of lipid were observed in retina including the epiretinal myelinated nerve fiber bundles, with no other neurotoxic effects. Little or no incorporation of [3h]dialkyl-PC was observed in the distal tissues of the optic system. With "labile" vesicles composed of egg lecithin, trace amounts of [3H]dialkyl-PC, and phosphatidic acid, no morphological changes occurred.