摘要:

The leukocyte migration inhibition (LMI) technique was used to measure the T cell-mediated immune response of Epstein-Barr-virus (EBV)-seropositive human donors to antigens associated with B cell lines of simian origin, transformed by simian EBV-like viruses, Herpesvirus papio (HVP), H. pan, H. gorilla and H. pongo. Extracts of cell lines carrying three of the four simian viruses (from gorilla, chimpanzee and orangutan) induced a positive LMI response, whereas lines carrying baboon-derived HVP were ineffective. None of the simian virus-transformed lines elicited an LMI reaction in human EBV-seronegative individuals. Leukocytes from patients with acute infectious mononucleosis (IM) failed to respond to any of the lines transformed by EBV or the simian EBV-like viruses. Such lines express the virally encoded nuclear antigen, but have only a low level of viral cycle-associated antigens. Extracts of the EBV-carrying human cell line P3HR-1 induced with 12-O-tetradecanoylphorbol-13-acetate to express high levels of early and virus capsid antigens (EA, VCA, respectively) however, elicited a strong response with leukocytes from patients with acute IM. During convalescence, IM patients became responsive to EBV, H. gorilla-, H. pan- and H. pongo-transformed lines, indicating that the LMI reaction induced by these simian virus-transformed lines was directed against the antigens expressed in immortalized cells rather than against antigens of the lytic cycle. It is highly probable that this reaction reflects a cross-recognition of the nuclear antigens associated with these four transforming viruses (excluding H. papio) at the level of human T cells.

ISSN:0300-5526    

DOI:10.1159/000149691

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Human leukocyte interferon (IFN-α) and acyclovir (ACV) have been used to establish human cytomegalovirus (HCMV) latency in infected human embryo lung fibroblast (HEL-F) cells. HCMV latency was maintained for a short interval (less than 9 days) after removal of inhibitors by increasing the incubation temperature. We now report a model system in which HCMV latency has been dramatically extended. HEL-F cells pretreated with IFN-α (200 IU/ml) and ACV (300 µM) were infected with a low MOI of HCMV, and treated for 23 days with the same inhibitor combination at 37 °. Infectious HCMV and virus antigens were undetectable at the time of inhibitor removal and remained undetectable during continued incubation at 40.5 °. A minimum of 0.4% of the cell population, however, contained a virus genome that could be reactivated at the time of inhibitor removal; this value declined to 0.0005% after 77 days at 40.5°. HCMV reactivation was achieved by maintaining the infected cells at 37° after inhibitor removal or by decreasing the incubation temperature to 37° at any time during maintenance at 40.5°. The HCMV genome was analyzed by blot hybridization in latently infected cells 23 days after inhibitor treatment at 37 ° or 4 days after inhibitor removal at 40.5 °. Although many HCMV-unique DNA genomic sequences were retained in HEL-F cultures after 23 days of inhibitor treatment, a significant reduction in retained HCMV sequences occurred after inhibitor removal and temperature shift to 40.5 °. The Xbal HCMV DNA fragments retained in the latently infected HEL-F cultures were present at a copy number of at least 0.5 copies per haploid cell genome

ISSN:0300-5526    

DOI:10.1159/000149692

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Sequence analysis of VPl in the DA strain of Theiler’s murine encephalomyelitis viruses (TMEV) showed that 13 of the first 23 N-terminal amino acids were identical to those in the corresponding protein of encephalomyocarditis virus. There was little similarity to the corresponding VPl sequences of poliovirus types 1,2 and 3, coxsackievirus B3, human rhinoviruses 2 and 14, human hepatitis A virus or foot-and-mouth disease virus. These results, as well as serological relationships detected by immunoblotting, suggest that the TMEV are more closely related to the cardioviruses than to the enteroviruses with which they are presently classified. This newly recognized relationship suggests potential for recombinant infectious cDNA studies between TMEV and cardioviruse

ISSN:0300-5526    

DOI:10.1159/000149693

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

9-β-D-Arabinofuranosyladenine (ara A) was shown to inhibit a specific step of tobacco mosaic virus (TMV) multiplication. The time course of the ara A-sensitive function occurred ‘late’ coinciding with the period of viral RNA and protein synthesis. When treatment began after viral RNA synthesis was established, 1.0 mMara A inhibited viral single-stranded RNA and viral protein synthesis, but not viral double-stranded RNA synthesis. Viral double-stranded RNA synthesis was inhibited totally only when treatment with ara A began within the first 4 h (before any RNA synthesis was detected), and the degree of inhibition decreased rapidly when treatments began at later times. In contrast, single-stranded TMV RNA synthesis and viral protein synthesis were inhibited throughout the infection. The mode of action of ara A against TMV involves selective inhibition of a function required for single-stranded RNA synthesis and viral protein synthesis without detectable inhibition of RNA or protein synthesis of the host or ongoing viral double-stranded RNA synth

ISSN:0300-5526    

DOI:10.1159/000149694

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

A number of cucurbit-infecting tobamoviruses have been reported in the past but there is confusion about their identity and relationships. Cucumber viruses 3 (CV3) and 4 (CV4) were originally described in the United Kingdom whereas the watermelon (W) and cucumber (C) ‘isolates’ of cucumber green mottle mosaic virus (CGMMV) came from Japan. The results of serological studies and RNA-cDNA analyses have shown that CV3, CV4 and CGMMV-W are very closely related, whereas CGMMV-C is quite different. It is concluded that there are two distinct tobamoviruses that infect cucurbits; they are only very remotely related to each other and to a number of other tobamoviruses. It is suggested that the name CGMMV be retained to include the isolates or strains CV3, CV4 and CGMMV-W, and that a new name, kyuri green mottle mosaic virus (KGMMV), be given to CGMM

ISSN:0300-5526    

DOI:10.1159/000149695

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

The involvement of cellular carbohydrates in the interaction of rabies virus with chicken embryo related cell receptors was investigated. Two different methodological approaches were employed: (1) specific glycosidases were used to treat the cells before infection, and (2) specific lectins were used to compete with the viral binding. The results indicate the participation of sialic acid, galactose, mannose, and N-acetyl-glucosamine but not fucose in the cellular requirements for rabies virus infection.

ISSN:0300-5526    

DOI:10.1159/000149696

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Antigenic cross-reactivity of the human acquired immunodeficiency disease syndrome virus LAV/HTLV-III with the lentiviruses visna virus, caprine arthritis encephalitis virus (CAEV), and equine infectious anemia virus (EIAV) was determined with indirect enzyme-linked immunosorbent assays, immunoblot analysis, and virus-specific polyclonal antisera. Nonreciprocal cross-reactivity was seen between the gag gene products p24 of LAV/HTLV-III and p28 of EIAV. Reciprocal cross-reactivity was seen between the gag gene product p28 of visna virus and CAEV. No cross-reactivity was detected between visna virus (or CAEV) and EIAV (or LAV/HTLV-III). This suggests a closer relationship of LAV/ HTLV-ΠI with EIAV than with visna virus or CAEV

ISSN:0300-5526    

DOI:10.1159/000149697

出版商:S. Karger AG    

年代:1986

数据来源: Karger

摘要:

Rotavirus gastroenteritis was studied by enzyme-linked immunosorbent assay (ELISA) and by PAGE from April 1983 to April 1985 at the Buenos Aires Ricardo Gutierrez Children’s Hospital and at the San Justo Children’s Hospital. Based on examination of 576 cases, rotavirus was identified in 109 (18.9%) cases by ELISA and in 99 (17.2%) cases by PAGE. As a diagnostic tool PAGE presented a sensitivity of 90.8% compared with ELISA. Compared with the control SA-11 genome, 84 samples (84.9%) presented a long electropherotype and 15 isolates (15.1%) presented a short electropherotype. We detected 35 different long electropherotypes and report a short electropherotype that did not show genome variation and was responsible for an outbreak in the San Justo Children’s Hospital population from September 1983 to July

ISSN:0300-5526    

DOI:10.1159/000149698

出版商:S. Karger AG    

年代:1986

数据来源: Karger