摘要:

The cauliflower mosaic virus ORF II encoding the aphid transmission factor (ATF) was mutagenized to introduce a BamHl restriction site upstream from the initiation codon and then cloned into an eukaryotic viral expression vector (Autographa californica nuclear polyhedrosis virus). All recombinant viruses tested in Spodopterafrugiperda (SF21) cells expressed a protein of about 18 kD which comigrated in PAGE with ATF from infected plants. Western blotting using an oligopeptide antiserum to ATF confirmed the identity of the 18-kD protein from infected cells as the product of the ORF II sequences (PI8). Subcellular fractionation of cells infected with the recombinant AcMNPV demonstrated that the expressed PI8 accumulated intracellularly in an insoluble form. Antiserum was produced in rabbit against the partially purified PI 8 expressed in SF21 cells. When used to immunogold label ultrathin sections of cauliflower mosaic virus (CaMV)-infected turnip tissue, this antiserum was shown to be highly specific, labelling only the electron-lucent inclusion bodies (containing PI8) and not other plant cellular components.

ISSN:0300-5526    

DOI:10.1159/000150257

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Mouse hybridoma clones were examined for their ability to support replication of herpes simplex virus (HSV). Infection of hybridoma clone 1 cells producing an antibody not specific for HSV resulted in a persistent infection with a continuous production of infectious virus, whereas infection of the parental myeloma cells X63-Ag8.653 led to an abundant virus production and extinction of the culture. In contrast, infection of hybridoma cells producing HSV-specific antibodies was restricted to a few weeks. Infectious virus was isolated for a maximum of 10 days and, afterwards, viral antigens were detected by immunofluorescence for a maximum of 18 days. The neutralizing capacity of the antibodies was not essential since the pattern of infection in clone III E8 cells, producing a non-neutralizing antibody, did not differ from that observed in clones 2c and VI A6, which produced highly and weakly neutralizing antibodies, respectively. After loss of viral antigen, HSV DNA was no longer detected by Southern blot hybridization in hybridoma clone 2c cells. Since no difference other than the specificity of the produced antibodies is suspected between the hybridoma clones, the results suggest that the presence of HSV-specific antibodies in the B-lymphoid cell cultures is responsible for virus elimination from the cells.

ISSN:0300-5526    

DOI:10.1159/000150258

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Electrophoresis on 5% polyacrylamide was used to analyze dsRNAs of 26 cucumber mosaic virus isolates propagated in Nicoîiana tabacum. There was variation between isolates in the migration of each of the dsRNAs 1,2, and 3. Comparison of the dsRNA profiles enabled each isolate to be allocated to 1 of 7 distinct dsRNA profile types. Two distinct and readily distinguishable isolates were mixed in planta and dsRNA from these infected plants compared with in vitro mixtures of them. All bands from both types were present, indicating that the differences were real and reproducible. This method is of value as a means of classifying cucumber mosaic virus isolates, as it more closely reflects a range of biological characteristics than do other methods currently used

ISSN:0300-5526    

DOI:10.1159/000150259

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

The proteolytic cleavage sites of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein precursor gpl60 and the fusion protein of respiratory syncytial virus (RSV) show a sequence homology. To study this homology two synthetic peptides corresponding to HIV-1-env-gpl60-aa 507–518 (KAKRRWQREKR) and RSV-F2-aa 130–136 (SKKRKRR) were synthesized. Human serum samples from HIV-positive or RSV-positive collections recognized the appropriate peptide in 90.6 or 37.2% respectively. No cross-reactivity towards the non-homologous peptide could be monitored in both serum collections. In contrast, antipeptide antibodies raised against both peptides demonstrate a high degree of cross-reactivity. These data indicate that the high specificity of the virus-induced antibodies may be a result of strong conformational restrictions at the proteolytic cleavage site of both proteins. Moreover, these observations are important for diagnostic purposes. Synthetic peptides are a valuable tool for HIV antibody screening. Our data provide information concerning the specificity of antigen-antibody interaction on a highly immunogenic HIV-1 epit

ISSN:0300-5526    

DOI:10.1159/000150260

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Pairs of viroid-specifíc oligonucleotide primers were selected and used in separate reverse transcription reactions coupled with the polymerase chain reaction to obtain DNA products of predetermined sizes characteristic of each viroid. The reaction conditions allowed efficient incorporation of small amounts of 32P-dATP which enabled rapid detection of the products in polyacrylamide gels. Using this method as well as probe hybridization, the presence of grapevine yellow speckle viroids 1 and 2 (previously known as GV1B) in grapevine samples from California was demonstrated, and it was established that the Australian grapevine viroid occurs in California. These comparisons provide the basis for uniform nomenclature of grapevine viroids found in different geographical regions

ISSN:0300-5526    

DOI:10.1159/000150261

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

EcoRl, Hindlll, and Pstl restriction fragments representing the entire genome of the DN-599 isolate, the American prototype strain, of bovine herpesvirus 4 (BHV-4) were cloned. These cloned restriction fragments were analyzed by restriction enzyme digestion, hybridization to Southern blots of BHV-4 (DN-599) DNA, and cross-hybridization of cloned fragments. The resulting data were used to construct restriction maps of the unique region of BHV-4 (DN-599) DNA for restriction enzymes EcoRl, Hindlll, and Pistl. The EcoRl and Hindlll restriction maps confirm those previously deduced for the DN-599 isolate by hybridization of cloned fragments of a European strain of BHV-4 to Southern blots of DN-599 DNA. The Pstl restriction map is the first reported for BHV-4.

ISSN:0300-5526    

DOI:10.1159/000150262

出版商:S. Karger AG    

年代:1992

数据来源: Karger