Immunological response of mice to the bovine respiratory syncytial virus fusion glycoprotein expressed in recombinant baculovirus infected insect cellsWalravens, K.; Matheise, J. P.; Knott, I.; Coppe, P.; Collard, A.; Didembourg, C.; Dessy, F.; Kettmann, R.; Letesson, J.-J.
doi: 10.1007/bf01718633pmid: 9526539
SummaryBovine respiratory syncytial virus (BRSV) is a major cause of respiratory disease in calves. The BRSV genome encodes two major glycoproteins, G and F, which are the major targets for the host antibody response. We have expressed the F glycoprotein in insect cells (Sf9) using a recombinant baculovirus vector. A comparison of the F protein expressed in mammalian and insect cells by SDS-PAGE showed that only part of the baculovirus-produced protein was soluble and processed like the native protein. The antigenicity of the soluble form of the F protein expressed in insect cells was identical to that of the F protein expressed in mammalian cells. Immunization with the F protein expressed in insect cells induced neutralizing antibodies in mice. This antigenic preparation adjuvanted with Quil-A produced an increased neutralizing antibody titer and induced protection.
Characterization of human rotavirus genotype P[8]G5 from Brazil by probe-hybridization and sequenceAlfieri, A. A.; Leite, J. P. G.; Nakagomi, O.; Kaga, E.; Woods, P. A.; Glass, R. I.; Gentsch, J. R.
doi: 10.1007/bf01718636pmid: 9526542
SummaryWe report the molecular characterization of rotavirus genotype P[8]G5 strains found in fecal specimens collected in four different regions of Brazil, using digoxigenin (dig)-labeled oligonucleotide probes, sequence analysis, and RNA-RNA hybridization. The closest sequence relationships of the neutralization antigens of these strains were to the VP4 protein of P1A[8]G1 strain KU (93.3% identity in amino acids 11 to 282) and to the VP7 protein of G serotype 5 strain OSU (87.6% identity in amino acids 8 to 232). Based on VP7 sequence differences, we designed dig-probes that allowed us to discriminate porcine OSU-like strains from G5 strains isolated from Brazilian infants. The genetic relationships of two P[8]G5 isolates to other rotavirus genogroups were analyzed by RNA-RNA hybridization with [32P]-GTP probes representative of serotypes P1A[8]G1 (Wa), P[8]G3 (AU17), and P9[7]G5 (OSU). The Brazilian P[8]G5 strains showed sequence homology with genes of Wa-like and OSU-like strains, suggesting that these two strains were naturally occurring reassortants between members of the Wa and porcine rotavirus genogroups. The identification of these strains in diverse geographic areas of Brazil underscores their stability and demonstrates the emergence of clinically important rotavirus diarrhea strains by reassortment.
Rotavirus G and P types circulating in Brazil: characterization by RT-PCR, probe hybridization, and sequence analysisLeite, J. P. G.; Alfieri, A. A.; Woods, P. A.; Glass, R. I.; Gentsch, J. R.
doi: 10.1007/bf01718637pmid: 9526543
SummaryWe used reverse transcription-polymerase chain reaction (RT-PCR) to determine the P and G genotypes of 130 culture-adapted rotavirus strains isolated from 181 fecal specimens of children under 5 years of age from 9 states and the Federal District of Brazil. The 4 genotypes found most commonly worldwide were also common in Brazil and P[8]G1 was the most prevalent (43%), followed by P[4]G2 (12%), P[8]G3 (6%), and P[8]G4 (6%). However, unusual types P[8]G5, P[6]G2, P[9]G1, P[9]G3, and mixed infections were responsible for 12% and 21% of the cases, respectively. Genotype G5 strains were detected in specimens collected in all 9 areas surveyed from all 4 regions of Brazil. The unusual strain diversity in Brazil suggests that when tetravalent rotavirus vaccines currently being developed are introduced into Brazil, laboratory surveillance will be essential to monitor protection against unusual strains, particularly those of genotype 5, as well as emergence of novel reassortants that may evolve from the large pool of children with mixed infections.
Identification and characterization of the guinea-pig cytomegalovirus glycoprotein H geneBrady, R. C.; Schleiss, M. R.
doi: 10.1007/bf01718640pmid: 9526546
SummarySubunit vaccines which target viral envelope glycoproteins offer promise for the prevention of congenital cytomegalovirus (CMV) infection. The guinea pig model of CMV infection is uniquely well suited to testing vaccines for prevention of congenital infection, since, in contrast to other animal cytomegaloviruses, the guinea pig CMV (GPCMV) crosses the placenta, producing intrauterine infection. Antibody to the CMV glycoproteins B (gB) and H (gH) appears to be important in conferring protective immunity. Unfortunately, little is known about specific GPCMV envelope glycoproteins. Sequencing of GPCMV genome fragments was therefore undertaken to test whether GPCMV encodes a gH homologue. Partial sequencing of theHind III A fragment of the GPCMV genome revealed an open reading frame of 2 169 nucleotides capable of encoding a protein of 723 amino acids. Computer matrix analyses demonstrated identity between this ORF and the gH coding sequences of other herpesviruses. The GPCMV gH ORF encodes 12 highly conserved cysteine residues, contains 9 potential N-linked glycosylation sites, and has a predicted Mr of 81.6 kDa. Northern blot hybridizations with gH-specific probes identified an abundant 5.1 kb mRNA with expression kinetics of an “early” gene. A polyclonal antiserum raised against a synthetic peptide derived from the deduced amino acid sequence of the gH ORF identified a virion-associated protein with an approximate Mr of 85-kDa, the putative GPCMV gH, in immunoblot assays.
B-cell epitopes of varicella-zoster virus glycoprotein IIKjartansdóttir, A.; Lycke, E.; Norrby, S. R.
doi: 10.1007/bf01718644pmid: 9526550
SummaryB-cell epitopes of varicella-zoster virus glycoprotein II were mapped by means of solid phase ELISA, synthetic oligopeptides (constructed according to the Davison-Scott sequencing of the varicella-zoster virus genome) and sera from varicellae and herpes zoster patients. The individual pattern of antibody peptide binding varied considerably but at least 9 more reactive sites seemed discernible. A 31-mer-peptide corresponding to a hydrophilic segment of the glycoprotein (aa 417–447) was constructed. This peptide reacted with 2 out of 4 varicellae and 5 out of 9 zoster sera, respectively.