Archives of Virology

Lascano, E.; Lerman, G.; Blejer, J.; Caccuri, R.; Berría, M.

doi: 10.1007/BF01321114pmid: 1309637

To determine the pathway adopted by peripherally inoculated Junin virus (JV) to reach the CNS, rat tissues were serially harvested to trace the sequence of viral progression from right hind footpad to brain. Immunoperoxidase (PAP) labeling of viral antigen, concomitantly with infectivity assays and histological examination of each selected sample, were carried out. As from the 2nd week post-infection (pi), neurological disease inducing 100% mortality at 1 month was evident. At day 5 pi, viral antigen was first detected at footpad level in epidermic and dermic cells, as well as in neighbouring myocytes; labeled macrophages infiltrating small nerve branches were also disclosed. As from 10–15 days pi, viral antigen became apparent along ipsilateral sciatic nerve structures and within lumbar spinal ganglion neurons, followed by a fast viral spread throughout CNS neurons that involved spinal cord and brain.

Lee, J.; Marshall, J.; Bowden, D.

doi: 10.1007/BF01321120pmid: 1729987

Thin section electron microscopy was used to investigate cellular changes associated with the replication of rubella virus (RV) in Vero cells and to compare these changes to those of the related alphavirus, Semliki Forest virus (SFV). Conspicuous membrane-bound cytoplasmic vacuoles analogous to the alphavirus replication complexes were observed in RV infected cells but not in mock infected cells. The vacuoles were characterised by membrane-bound vesicles measuring about 60 nm which often displayed an irregular dense core and/or a network of fibres. These vesicles were morphologically distinct from RV particles and were generally located at regular intervals on the inner side of the surrounding membrane of the RV replication complex. Degenerating cellular material was often found in the membrane-bound vacuole of a replication complex. The replication complexes were intimately associated with the rough endoplasmic reticulum (RER), which was localised 45–75 nm from the surrounding membrane of the replication complex. Parallel studies of replication complexes in SFV infected cells did not reveal such an intimate association with the RER. RV replication complexes appeared as early as 8 h post infection (p.i.), before detection of RV particles by electron microscopy, and their peak production at 24 h p.i. coincided with the time of maximum virus titre.

Whetstone, C.; Miller, J.; Seal, B.; Bello, L.; Lawrence, W.

doi: 10.1007/BF01321129pmid: 1309641

A bovine herpesvirus 1 (BHV 1) mutant variant with a deletion in the thymidine kinase (TK) gene was assessed for its ability to establish latency and be reactivated in cattle. After treatment with dexamethasone, reactivated TK− BHV 1 was isolated from one of four cattle that received virus by intravenous inoculation only, and from four of four cattle that received virus by intranasal, intravaginal, and intravenous inoculation. Results prove that TK− BHV 1 will establish latency and can be reactivated in the natural host.

doi: 10.1007/BF01321131pmid: N/A

Takiguchi, K.; Sugawara, K.; Hongo, S.; Nishimura, H.; Kitame, F.; Nakamura, K.

doi: 10.1007/BF01321113pmid: 1729984

The effects of serum antibody on the replication of influenza C virus in the nose and lung were evaluated in rats challenged with the virus by the intranasal and endotracheal routes, respectively. Convalescent rat serum administered intraperitoneally prior to infection suppressed virus replication significantly in both the nasal and pulmonary tissues. Resistance achieved was however much greater in the lung than in the nose. Rats with a serum neutralizing antibody titer of 1:800 showed almost complete resistance to pulmonary virus infection, and virus yield from the lung was reduced 10- to 100-fold in animals with the antibody titer of 1:80–160 or less. In contrast, significant decrease in virus shedding from the nose was observed only in animals with a serum antibody titer of 1:800 or greater. The effect of adoptive transfer of monoclonal antibodies (MAbs) to haemagglutinin-esterase (HE) glycoprotein and matrix (M) protein on pulmonary virus replication was also examined. Anti-HE MAbs with neutralization activity prevented virus shedding from the lung almost completely whereas non-neutralizing anti-HE MAb and anti-M Mab showed no inhibitory effect.

Mattos, C.; Mattos, Cecilia; Dangler, C.; Osburn, B.; Ianconescu, M.; Kaufmann, Rozalia

doi: 10.1007/BF01321115pmid: 1309643

Partial cDNA clones representing 47%, 96%, and 98% of genome segments 7, 9, and 10, respectively, of a US bluetongue virus (BLU) 11 virulent strain were used to study, for the first time, the genetic relationships between Israeli BLU proto-serotypes and field isolates, and US BLU proto-serotypes. Their usefulness as group-specific identification probes was also determined. The viral nucleic acid was extracted from the infected cells and the purified dsRNA genome segments were fractionated by polyacrylamide gel electrophoresis, transferred to a nylon membrane and hybridized to the32P labeled DNA probes. The three probes recognized all the samples tested. Genome segment 7, that code for the mayor inner capsid protein VP7, showed the most variation in the hybridization signal with the US proto-serotypes and all the Israeli samples studied. The genome segments 9 and 10 that code for the minor inner capsid protein VP6 and the nonstructural protein NS3, respectively, were highly conserved in all the samples tested despite their distant geographical regions of origin. The last two mentioned clones showed to be good group-specific probes for the identification of BLU samples from Israel and United States. The obtained cloned genetic probes were also tested against US epizootic haemorrhagic disease virus (EHDV) serotype 1 and 2 viral dsRNA, a distantly related orbivirus. None of them hybridized with the viral dsRNA of these two viruses.

AbdelMagid, O.; Orten, D.; Xue, W.; Blecha, F.; Minocha, H.

doi: 10.1007/BF01321125pmid: 1309639

A panel of murine monoclonal antibodies (MAbs) to bovine herpesvirus-1 (BHV-1) was prepared. Three of them were neutralizing MAbs and reacted against 130/75/50 kDa, 77 kDa, or 97 kDa glycoproteins (gp). A fourth non-neutralizing MAb recognized the 97 kDa gp. Competition radioimmunoassay demonstrated that each of the four MAbs reacted against a different virus epitope. Anti-idiotypic antibodies (anti-id) to the four MAbs were produced in rabbits and purified by sequential immunoaffinity chromatography. Each anti-id inhibited the binding of its respective MAb to BHV-1 in competitive ELISA and blocked BHV-1 neutralizing activity of the MAb. This inhibition suggested that the anti-ids were specific for the antigen binding site of the MAbs. Treatment of MDBK cells with anti-ids inhibited BHV-1 infection, which suggested that the anti-ids block a cellular component essential for virus infection. Absence of significant cross-reactivity among the anti-ids for heterologous MAbs indicated that they recognized unique determinants on the antigen binding site of the homologous MAb.

Latham, Patricia; Sepelak, Susan

doi: 10.1007/BF01321126pmid: 1370368

The Adames strain of a bunyavirus, Punta Toro virus (PTV), is an hepatotrophic virus that has been described to produce an age-dependent lethal hepatic necrosis in 3–4 week old C57BL/6 mice, but 8 week old mice survive with minimal necrosis. The course of PTV infection in vitro in macrophages derived from these mice served as a model to study the pathogenesis of phlebovirus infection. Peripheral blood monocytes, resident or elicited peritoneal macrophages, and Kupffer cell liver macrophages, as well as hepatocytes, were able to support replication of PTV in vitro to a variable extent. Kupffer cells were the only population of macrophages, however, that expressed an age-related ability to affect viral infection and replication in vitro, suggesting that liver macrophages may have a unique modulatory effect on the occurrence and severity of PTV-induced hepatitis in mice. Whereas PTV showed minimal replication in resident peritoneal macrophages, the virus could replicate effectively in peritoneal macrophages elicited by thioglycolate. Activation of peritoneal macrophages with endotoxin resulted in a significant inhibition of intrinsic PTV replication (p<0.001), and a modest extrinsic inhibitory effect on PTV replication in cocultured hepatocytes. Both effects persisted in the presence of antiinterferon. These results indicate that the source and state of activation of macrophage/monocyte populations can influence the course of infection in vitro by the phlebovirus, Punta Toro, and can modulate infection in cocultured target cells.

Tao, Hung; Jing-Yi, Zhou; Yun-Ming, Tang; Tong-Xing, Zhao; Baek, L.; Lee, H.

doi: 10.1007/BF01321127pmid: 1346088

The etiologic agent of haemorrhagic fever with renal syndrome (HFRS), Hantaan virus, was first isolated in 1976. Since then numerous Hantaan-like viruses have been isolated and five serotypes of Hantavirus have been recognized. Serological studies indicate that these viruses are globally distributed, with each serotype occurring in specific areas. Hantaan virus has been intensively studied antigenically, biochemically, and genetically. However there is still a paucity of information on the pathogenesis of Hantaan virus in the human host.

Vahlne, A.; Larsson, P.; Horal, P.; Ahlmén, J.; Svennerholm, B.; Gronowitz, J.; Olofsson, S.

doi: 10.1007/BF01321118pmid: 1309645

Nontoxic concentrations of Cyclosporin A (CyA) dose-dependently inhibited herpes simplex virus (HSV) production in resting monkey kidney cells. The block was at the step of virus DNA synthesis as assessed by [3H]thymidine incorporation and by dot blot hybridization of infected cell DNA using a cloned32P-labelled HSV DNA fragment (BamHI X) as probe. This was further supported by analysis of HSV protein synthesis in the presence of CyA as assessed by sodium dodecyl sulphate polyacrylamide gel electrophoresis and Western blot. A relative accumulation of HSV α- (e.g., ICP 4) and β1-proteins (e.g., ICP 6 and 8) was found, whereas HSV γ1-proteins were slightly decreased and γ2-proteins were markedly decreased by CyA. The production of thymidine kinase and DNA polymerase was decreased when CyA was added to HSV infected cells. The sensitivity to CyA was not escaped by thymidine kinase nor DNA polymerase deficient mutants. Passage of HSV in presence of CyA did not result in induction of drug resistance.