摘要:

The effect of normal or sensitized spleen cell transfer from syngeneic euthymic mice to Junin virus-infected suckling athymic mice was studied. Transfer was performed 1 or 7 days after infection. In both cases, an acute lethal disease developed 6–11 days after transfer. The mortality reached 100% in all infected groups receiving normal or sensitized splenocytes, while it was negligible for different control groups of athymic mice. Transfer of normal or sensitized splenocytes was unable to significantly modify brain viral titers, as compared with infected nontransferred athymic mice killed after a 25-day observation period. Brain lesions were demonstrated in about half of the infected athymic mice transferred with sensitized splenocytes and in all euthymic infected mice. These results show that splenocyte transfer from immunocompetent donors is able to change the normal course of persistent Junin virus infection in nude mice to a lethal acute disease, thus pointing to a main role for T cells in its pathogenesi

ISSN:0300-5526    

DOI:10.1159/000150030

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Binding of herpes simplex virus (HSV) type 1 to the various subclasses of human serum lipoproteins was investigated. Studies were performed with human serum lipoproteins purified by differential ultracentrifugation and artificial proteoliposomes containing only one type of apolipoprotein (Al5 E) by using an enzyme-linked immunosorbent assay technique, column chromatography, and electron microscopy. All tested lipoprotein subclasses (very low, low-, high-density lipoproteins; VLDL, LDL, HDL, HDLi) showed significant binding of purified HSV type 1. Furthermore, HSV bound to all different synthetic proteoliposomes. Adsorption of envelope proteins isolated from purified HSV to Sepharose-bound lipoproteins revealed binding of HSV glycoprotein B. Based on these results we reached the conclusion that in HSV-lipoprotein complex formation the lipid component in the lipoproteins and the glycoprotein B in HSV are the preferential reaction partners.

ISSN:0300-5526    

DOI:10.1159/000150031

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Epstein-Barr virus (EBV) has previously been classified into two different types according to the organization of the EB nuclear antigen 2 (EBNA2) gene region. Type A virus hybridizes with probes from B95–8 or M-ABA viruses and the B type virus with probes from the Jijoye virus strain. The substituted region in EBVtype B codes for a different, but related EBNA2 antigen, named EBNA2B as opposed to EBNA2A. In this study Burkitt lymphoma cell lines, previously typed according to the EBV viral genomes they carry, as well as some matching lymphoblastoid cell lines were examined by immunoblotting for the expression of both EBNA1 and EBNA2 antigens. Variation in the molecular weight of EBNA1 indicated that both A and B virus types contained a variety of different virus isolates. EBNA2A was identified in all lines carrying A type viral genomes, but was not observed in any of the lines harboring B type virus. EBNA2B was identified in 4 of 10 Burkitt lymphoma lines carrying EBV type

ISSN:0300-5526    

DOI:10.1159/000150032

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

We characterized nucleocapsid (NC) forms generated during infection with human cytomegalovirus (HCMV) strains AD169 and Towne. Two morphological forms of NC were isolated by Renografin-76 banding of the nuclear (N) or cytoplasmic (C) fractions of infected cells. SDS-PAGE analysis of the N- and C-NC forms of AD169 and Towne showed the presence of three polypeptides (150,33, and 30 KD). The C-NC contained five additional polypeptides (260, 112, 110, 68, and 54 KD) with a counterpart in the mature virion. An additional polypeptide of 37 KD (Towne) or 39 KD (AD169) was only present in the B-NC and not in the A-NC, C-NC, or the mature virion. These polypeptides were basic as determined by two-dimensional PAGE analysis. The 37-KD (Towne) and the 39-KD (AD169) polypeptides were phosphorylated. The NC polypeptides were HCMV specific as shown by immunoprecipitation using a pool of HCMV-positive human antisera. The B-NC DNA was shown to have a restriction pattern identical to that of the infectious viral DNA, but no DNA was detected in the A-NC form. Analysis of NC forms by pulse-chase experiments identified a ‘pre-NC peak which may serve as a precursor to the A- and B-NC form

ISSN:0300-5526    

DOI:10.1159/000150033

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Two DNA-negative temperature-sensitive mutants of human cytomegalovirus strain AD 169 were shown to be deficient in induction of several prominent viral polypeptides when grown in human foreskin fibroblasts under nonpermissive conditions. The use of a monospecific polyclonal antiserum allowed recognition of a further defect in processing of an ‘early’ viral polypeptide of 135

ISSN:0300-5526    

DOI:10.1159/000150034

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The human beta interferon (hlFNβ1) gene has been cloned into a bovine papillomavirus type 1 (BPV-1)/pML2 vector. The recombinant DNAs can be maintained as stable plasmids in mouse cells, with no detectable rearrangements. The linked hIFNβ1 gene is inducible with little line-to-line variability in independently transformed cell lines. The hlFN β1 gene is equally induced when it is inserted adjacent to or away from the BPV-1 enhancer. The great stability of the BPV-1/pML2 vector has allowed us to study the regulation of the hlFNβ1 gene in mouse cells, with the construction of deleted and hybrid hlFNβ1 genes. Using this strategy, we have confirmed that the 5’ sequences of the hlFNβ1 gene are involved in the induction mechanism. The entire hlFNβ1 regulatory element is able to express heterologous genes with no induction, suggesting that the negative regulatory sequences present in the 3’ region of the hlFNβ1 regulatory element are not fully active on heterol

ISSN:0300-5526    

DOI:10.1159/000150035

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Tubulovesicular structures, measuring 20–50 nm in diameter, were found in dilated neuronal processes in brains from mice infected with the Fujisaki strain of Creutzfeldt-Jakob disease virus. These particles were similar to those observed in brains from hamsters infected with scrapie. These structures are consistently present in naturally occurring and experimentally induced spongiform encephalopathies, irrespective of the host species or virus strain. Their role in pathogenesis is undetermine

ISSN:0300-5526    

DOI:10.1159/000150036

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Single-stranded RNAs from Lassa virus-infected cells were fractionated by affinity chromatography on an oligo(dT)-cellulose column as well as by sucrose gradient centrifugation. Fractionated RNAs were translated in rabbit reticulocyte lysates, and translation products were precipitated with monoclonal antibodies to the nucleocapsid protein of Lassa virus. It has been shown that mRNA for the nucleocapsid protein is 15–16S and the RNA does not contain long if any poly(A) sequence

ISSN:0300-5526    

DOI:10.1159/000150037

出版商:S. Karger AG    

年代:1988

数据来源: Karger