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PubMed2006

High titers of circulating maternal antibodies suppress effector and memory B-cell responses induced by an attenuated rotavirus priming and rotavirus-like particle-immunostimulating complex boosting vaccine regimen.

We investigated maternal antibody (MatAb) effects on protection and immune responses to rotavirus vaccines. Gnotobiotic pigs were injected intraperitoneally at birth with pooled serum from sows hyperimmunized with human rotavirus (HRV); control pigs received no sow serum. Pigs with or without MatAbs received either sequential attenuated HRV (AttHRV) oral priming and intranasal boosting with VP2/VP6 virus-like particle (VLP)-immunostimulating complex (ISCOM) (AttHRV/VLP) or intranasal VLP-ISCOM prime/boost (VLP) vaccines at 3 to 5 days of age. Subsets of pigs were challenged at 28 or 42 days postinoculation with virulent Wa HRV to assess protection. Isotype-specific antibody-secreting cell (ASC) responses to HRV were quantitated by enzyme-linked immunospot assay to measure effector and memory B-cell responses in intestinal and systemic lymphoid tissues pre- and/or postchallenge. Protection rates against HRV challenge (contributed by active immunity and passive circulating MatAbs) were consistently (but not significantly) lower in the MatAb-AttHRV/VLP groups than in the corresponding groups without MatAbs. Intestinal B-cell responses in the MatAb-AttHRV/VLP group were most suppressed with significantly reduced or no intestinal immunoglobulin A (IgA) and IgG effector and memory B-cell responses or antibody titers pre- and postchallenge. This suppression was not alleviated but was enhanced after extending vaccination/challenge from 28 to 42 days. In pigs vaccinated with nonreplicating VLP alone that failed to induce protection, MatAb effects differed, with intestinal and systemic IgG ASCs and prechallenge memory B cells suppressed but the low intestinal IgA and IgM ASC responses unaffected. Thus, we demonstrate that MatAbs differentially affect both replicating and nonreplicating HRV vaccines and suggest mechanisms of MatAb interference. This information should facilitate vaccine design to overcome MatAb suppression.

Animals↗

PubMed1990

Homotypic serum antibody responses to rotavirus proteins following primary infection of young children with serotype 1 rotavirus.

The class-specific antibody responses to serotype 1 rotavirus structural proteins were examined by immunoblotting with sera obtained from young children hospitalized with acute rotavirus diarrhea caused by serotype 1. All were believed to be primary infections. Three consecutive samples were obtained from 16 patients during the acute and convalescent phases of the disease and then approximately 4 months later. Immunoglobulin G (IgG)-class antibody responses to two inner capsid proteins (VP2 and VP6) and to the major homologous outer capsid protein (VP7) were detected in all patients. Antibody responses to VP6 were rapid, increased in intensity during 20 to 40 days after the onset of symptoms, and persisted for more than 4 months. Responses to VP2 and VP7 were more delayed, were maximal in convalescent-phase sera, and decreased markedly in intensity 4 months after the onset of symptoms in the majority of children. Two patients with evidence of mixed infection showed persisting high levels of antibody to VP7. Responses to the outer capsid protein VP4 were detected in 67% of patients, peaked at 20 to 40 days after the onset of symptoms, and were no longer detected at 4 months in the majority of patients. It is likely that the immunoblotting technique underestimated responses to VP4. Acute- and convalescent-phase sera (known to contain antirotavirus IgM or IgA measured by enzyme immunoassay) were also examined by immunoblotting. IgM- and IgA-class antibody responses to viral proteins VP2, VP4, and VP7 appeared to be qualitatively identical to those observed for IgG in the same serum samples.

Antibodies, Viral↗

PubMed2002

Frequent reassortments may explain the genetic heterogeneity of rotaviruses: analysis of Finnish rotavirus strains.

The predominant rotavirus electropherotypes (e-types) during 17 epidemic seasons (1980 through 1997) in Finland were established, and representative virus isolates were studied by nucleotide sequencing and phylogenetic analysis. The virus isolates were either P[8]G1 or P[8]G4 types. The G1 and G4 strains formed one G1 lineage (VP7-G1-1) and one G4 lineage, respectively. Otherwise, they belonged to two P[8] lineages (VP4-P[8]-1 and -2) unrelated to their G types. Phylogenetic analysis of partial sequences of all 11 RNA segments obtained from the strains also revealed genetic diversity among gene segments other than those defining P and G types. With the exception of segments 1, 3, and 10, the sequences of the other segments could be assigned to 2 to 4 different genetic clusters. The results of this study suggest that, in addition to the RNA segments encoding VP4 and VP7, the other RNA segments may segregate independently as well. In total, the 9 predominant e-types represented 7 different RNA segment combinations when the phylogenetic clusters of their 11 genes were determined. The extensive genetic diversity and number of e-types among rotaviruses are best explained by frequent genetic reassortment.

Antigens, Viral↗

PubMed2006

Intrarectal immunization with rotavirus 2/6 virus-like particles induces an antirotavirus immune response localized in the intestinal mucosa and protects against rotavirus infection in mice.

Rotavirus (RV) is the main etiological agent of severe gastroenteritis in infants, and vaccination seems the most effective way to control the disease. Recombinant rotavirus-like particles composed of the viral protein 6 (VP6) and VP2 (2/6-VLPs) have been reported to induce protective immunity in mice when administered by the intranasal (i.n.) route. In this study, we show that administration of 2/6-VLPs by the intrarectal (i.r.) route together with either cholera toxin (CT) or a CpG-containing oligodeoxynucleotide as the adjuvant protects adult mice against RV infection. Moreover, when CT is used, RV shedding in animals immunized by the i.r. route is even reduced in comparison with that in animals immunized by the i.n. route. Humoral and cellular immune responses induced by these immunization protocols were analyzed. We found that although i.r. immunization with 2/6-VLPs induces lower RV-specific immunoglobulin G (IgG) and IgA levels in serum, intestinal anti-RV IgA production is higher in mice immunized by the i.r. route. Cellular immune response has been evaluated by measuring cytokine production by spleen and Peyer's patch cells (PPs) after ex vivo restimulation with RV. Mice immunized by the i.n. and i.r. routes display higher gamma interferon production in spleen and PPs, respectively. In conclusion, we demonstrate that i.r. immunization with 2/6-VLPs protects against RV infection in mice and is more efficient than i.n. immunization in inducing an anti-RV immune response in intestinal mucosa.

Animals↗

PubMed1993

Variation in rotavirus virulence: a comparison of pathogenesis in calves between two rotaviruses of different virulence.

Variation in virulence between two bovine rotaviruses was investigated using ten female and ten male 10-day-old gnotobiotic calves of five breeds or cross breeds that were inoculated with a virulent strain or a strain of low virulence. Similar numbers of infectious viral particles were detected in feces of calves inoculated with either virus, but diarrhea, xylose malabsorption, and reduction of villus height occurred only after inoculation with virulent virus. The mean percentage of the area of the villus epithelium per villus immunostained for rotavirus antigen was eight times greater in calves inoculated with virulent virus, and the mean percentage of villi on which immunostained enterocytes were detected was twice as large in calves inoculated with virulent virus than in calves inoculated with the virus of low virulence. Mean crypt death and mean crypt cell production rates were increased after inoculation with either virus. Virulence was associated with extensive spread of infection through the small intestine, preferential colonization of the proximal small intestine, and marked damage to enterocytes and villi. The virus of low virulence infected the proximal small intestine poorly, and although it infected more enterocytes in the mid and distal small intestine and replicated in them, causing cytopathic effects, it did not damage intestinal structure and affect function.

Animals↗

PubMed1998

Prevention of rotavirus disease: guidelines for use of rotavirus vaccine. American Academy of Pediatrics.

Virtually all children experience rotavirus (Rv) infection before school entry. In the United States and other temperate countries, Rv disease peaks in the winter and during this time is responsible for the majority of episodes of diarrhea in infants and young children. 1-4 Data collected by the Centers for Disease Control and Prevention from 1979 through 1992 indicate that approximately 50 000 hospitalizations attributable to Rv occur annually in the United States, a number that approximates about 1 in 78 children being hospitalized with Rv diarrhea by 5 years of age.2,5 RotaShield (Wyeth-Lederle Vaccines and Pediatrics, Philadelphia, PA) was licensed by the Food and Drug Administration on August 31, 1998, for oral administration to infants at 2, 4, and 6 months of age. The rationale for using Rv immunization for prevention or modification of Rv disease is based on several considerations. First, the rate of illness attributable to Rv among children is comparable in industrialized and developing countries, which indicates that improved public sanitation is unlikely to decrease the incidence of disease.6,7 Second, although implementation of oral rehydration programs to prevent dehydration has improved in the United States, widespread use is inadequate to prevent significant morbidity.8-11 Third, trials of rhesus rotavirus-tetravalent (Rv) vaccine in the United States, Finland, and Venezuela show efficacy rates of approximately 80% for prevention of severe illness and 48% to 68% against Rv-induced diarrheal episodes.12-16 These results are similar to the protection observed after natural Rv infection, which also confers better protection against subsequent episodes of severe disease than against mild illness.17-19 This statement provides recommendations regarding the use of Rv vaccine in infants in the United States.

Antibodies, Viral↗

PubMed1992

Rotavirus infection in horses. Genome profile analysis of a rotavirus isolated from an infected foal.

Electrophoretic analysis in polyacrylamide gel (PAGE) of the equine rotavirus 106/88/LI/EQ, isolated from the diarrhea of an 18 day old foal was compared to the bovine strain NCDV. There was a notable difference in the migration of some segments of the viral RNA. Bands 2 and 3 of the equine rotavirus comigrated while there was a clear separation of segments 7, 8 and 9. Moreover, the migration of segments 1, 4 and 5 revealed a lower molecular weight than the corresponding segments of NCDV.

Animals↗

PubMed1986

Antibodies specific for the carboxy-terminal region of the major surface glycoprotein of simian rotavirus (SA11) and human rotavirus (Wa).

Antibodies specific for the major outer capsid protein (VP7) of the simian rotavirus SA11 were obtained by immunization of rabbits with a synthetic peptide, Ser-Ala-Ala-Phe-Tyr-Tyr-Arg-Val, corresponding to the eight carboxy-terminal amino acids of the viral protein predicted from the nucleotide sequence of the gene segment 9 of the SA11 genome. As the carboxy-terminal region of the VP7 of human rotavirus Wa has an identical sequence, cross-reactivity of the raised antibodies was observed with this strain.

Antibodies, Viral↗

PubMed1994

Serum IgA immune response to individual rotavirus polypeptides in young children with rotavirus infection.

A human IgA-radioimmunoprecipitation assay (IgA-RIPA) utilizing the galactose-binding lectin jacalin from the jack-fruit Artrocarpus integrifolia was developed. Among the human immunoglobulins, jacalin binds specifically to immunoglobulin A. The IgA-RIPA was used to characterize the serum IgA response to individual rotavirus polypeptides in nine paired sera from children (8-34 months of age) with an acute rotavirus infection. In acute sera the IgA response was mainly directed against the inner capsid proteins VP2 and VP6, with VP2 surprisingly being the most immunogenic protein while in the convalescent sera, the IgA response was directed not only against structural but also against non-structural proteins.

Antibodies, Viral↗

PubMed1985

Nucleotide sequence of the structural glycoprotein VP7 gene of Nebraska calf diarrhea virus rotavirus: comparison with homologous genes from four strains of human and animal rotaviruses.

A full-size cloned cDNA copy of the rotavirus gene encoding the structural neutralization glycoprotein (VP7) of Nebraska calf diarrhea virus (NCDV), a strain recently shown to be effective as a vaccine in children, has been sequenced. Comparison of the deduced amino acid sequence of NCDV (serotype 6) VP7 with that of four other rotavirus strains (human WA serotype 1, human HU-5 serotype 2, simian SA-11 serotype 3, and bovine UK serotype 6) indicates that the degree of amino acid homology among VP7 neutralization proteins of these serotypes ranges from 75 to 86%. Four hydrophilic regions at amino acid residues 174-183, 248-256, 287-294, and 310-317 exhibit significant homology and hence may represent common antigenic determinants, while one hydrophilic area at amino acid residues 83-102 exhibits sufficient divergence to suggest it may be involved in serotype specificity.

Amino Acid Sequence↗

PubMedDate not supplied

Analysis of gene selection in reassortant formation between canine rotavirus K9 and human rotaviruses with different antigenic specificities.

A number of antigenic mosaic reassortants which have neutralization proteins VP4 and VP7 derived from different parental strains were analysed in order to study gene selection in reassortant formation between animal and human rotaviruses (HRV). These reassortants were isolated from mixed infection of MA-104 cells with canine rotavirus strain K9 (subgroup I and G serotype 3) and HRV strains (with subgroup I or II antigen and G serotype 1-4, 9 or 12 antigen), through repeated selections with anti-VP4 and anti-VP7 neutralizing monoclonal antibodies directed specifically at HRV and K9, respectively. By serological and genomic analyses, all the isolated clones were found to be antigenic mosaic reassortants possessing VP4 of K9 and VP7 of HRV. In the reassortants between strain K9 and one of the six strains of subgroup II HRV, a single or a few genotypes with particular constellations of RNA segments were predominant, with only a few RNA segments including gene 4 (encoding VP4) being derived from K9. In contrast, in the reassortants between strain K9 and any one of the subgroup I HRV, more than nine different genotypes were identified and various RNA segments, except for segments 8 and 10, were derived from K9. These findings indicated that the RNA segments of K9 might be reassorted more readily with those of subgroup I HRV than with those of subgroup II HRV, suggesting the possible existence of functional mechanisms which determine the extent of diversity of genome selection depending on the pairs of parent strains in the reassortant formation.

Animals↗

PubMedDate not supplied

Genotypic diversity of reassortants between simian rotavirus SA11 and human rotaviruses having different antigenic specificities and RNA patterns.

A total of 200 clones of reassortants were generated in vitro between simian rotavirus SA11 (SA11-L2 strain) and each of five human rotavirus (HRV) strains with different antigenic specificities and RNA patterns. When culture fluid coinfected with parent viruses was subjected to repeated selection with anti-HRV-VP4 and anti-SA11-VP7 neutralizing monoclonal antibodies, all yielded progenies were antigenic mosaic reassortants possessing VP4 and VP7 derived from SA11 and HRV, respectively. In genomic analysis of viral RNA by PAGE, two and five different genotypes were identified in 40 clones, generated between SA11 and HRV strain Hochi (G serotype 4, G4) and between SA11 and KU (G1), respectively. In contrast, 11 and 17 genotypes were found in progenies between SA11 and subgroup I G2 HRV strain HN126 or DS-1, respectively. Although SA11 genes, except for the VP7 gene, were predominant in most reassortants, gene 5 was preferentially selected from HRV. Incorporation of HRV segments 1, 3 and 10 into progenies was more frequent in SA11 x HN126 and SA11 x DS-1 reassortants than in other reassortants. These results indicated that the extent of diversity of reassortant genotypes differs between the two groups of the parental HRV strain; one has subgroup I specificity and a short RNA pattern (DS-1 genogroup), while the other has subgroup II specificity and a long RNA pattern (Wa genogroup).

Animals↗

PubMed1987

Use of bovine milk concentrate containing antibody to rotavirus to treat rotavirus gastroenteritis in infants.

The use of a concentrate containing milk immunoglobulins prepared from rotavirus-hyperimmunized cows (neutralization titer, 1:6,000 for a 10% solution) to treat infants hospitalized for acute rotavirus gastroenteritis resulted in a significant (P = .008) reduction in the duration of excretion of virus. Stool samples from treated infants showed the presence of bovine milk immunoglobulins in 47% of cases and of neutralizing activity in 43% (mean neutralization titer, 1:48); stool samples from control infants showed neutralizing activities in only 3% of cases (neutralization titers, less than 1:20). Immunoelectrophoresis of stool extracts revealed fragment A, a bovine analogue of F(ab')2 or Fab, as the major product of in vitro and in vivo digestion of the immunoglobulins. Cessation of excretion of virus correlated with the appearance of neutralizing activities in 19 of 25 infants. Only concentrate-treated infants with high neutralizing activity in stools showed a statistically significant reduction in duration of excretion of virus; this duration in concentrate-treated infants with low neutralizing activity was comparable with controls.

Animals↗

PubMed1987

Reassortment of human rotavirus possessing genome rearrangements with bovine rotavirus: evidence for host cell selection.

Mixed infections of secondary rhesus monkey kidney cells with human rotaviruses carrying rearranged genomes and with bovine rotavirus yielded a high percentage of reassortants. The genotypes of 511 plaque-purified clones raised in either MA104 or BSC-1 cells have been determined and the frequencies of different genotypes have been calculated. It was found that reassortants did not emerge at random; there was non-random association of certain genes; the cell line used to isolate reassortants influenced the result, i.e. host cell factors had a selective effect on a recombinational mixture.

Animals↗

PubMed1982

Assay of human rotavirus antibody by immune adherence hemagglutination with a cultivable human rotavirus as antigen.

A cultivable human rotavirus, Wa, was propagated in MA-104 cells and used as an antigen in immune adherence hemagglutination (IAHA) and complement fixation (CF) tests. IAHA antibody titers of sera from normal humans were found to be eightfold higher than CF antibody titers. The IAHA antibody determination with the Wa antigen is considered to be especially useful for the seroepidemiological studies of human rotavirus infections.

Antibodies, Viral↗

PubMed1988

Ability of TESTPACK ROTAVIRUS enzyme immunoassay to diagnose rotavirus gastroenteritis.

TESTPACK ROTAVIRUS, a simple 10-min enzyme immunoassay, was compared with electron microscopy and Pathfinder enzyme immunoassay on feces from 172 patients of various ages with gastroenteritis. The percent sensitivities and specificities before blocking with antiserum were as follows: TESTPACK, 100% sensitivity and 99% specificity; Pathfinder, 95% sensitivity and 98% specificity. After blocking, the sensitivity and specificity, respectively, were 100% and 100% for TESTPACK and 95% and 99% for Pathfinder. TESTPACK ROTAVIRUS was more sensitive, but not significantly, than Pathfinder (P greater than 0.1) and the direct electron microscopy technique (P greater than 0.1).

Feces↗

PubMed2006

Hsp70 negatively controls rotavirus protein bioavailability in caco-2 cells infected by the rotavirus RF strain.

Previous studies demonstrated that the induction of the heat shock protein Hsp70 in response to viral infection is highly specific and differs from one cell to another and for a given virus type. However, no clear consensus exists so far to explain the likely reasons for Hsp70 induction within host cells during viral infection. We show here that upon rotavirus infection of intestinal cells, Hsp70 is indeed rapidly, specifically, and transiently induced. Using small interfering RNA-Hsp70-transfected Caco-2 cells, we observed that Hsp70 silencing was associated with an increased virus protein level and enhanced progeny virus production. Upon Hsp70 silencing, we observed that the ubiquitination of the main rotavirus structural proteins was strongly reduced. In addition, the use of proteasome inhibitors in infected Caco-2 cells was shown to induce an accumulation of structural viral proteins. Together, these results are consistent with a role of Hsp70 in the control of the bioavailability of viral proteins within cells for virus morphogenesis.

Caco-2 Cells↗

PubMed1991

[Stimulation of serum antibody formation in pigs by oral, subcutaneous or combined administration of live porcine rotaviruses or intramuscular inoculation of inactivated porcine rotaviruses in an oil adjuvant].

Only live vaccines prepared from attenuated strains have been used for the specific prophylaxis of rotavirus infections in pigs. These vaccines are administered to sows per os or parenterally to increase the content of antibodies in the blood serum, colostrum and milk, and in this way to provide for the better passive protection of suckling piglets through the maternal antibodies, or to induce the active immunity by pig vaccination. The data on the efficiency of live vaccines administered in both ways differ as to their ability to stimulate significantly increases in the actual levels of antibodies in sows and also as to the possibility of inducing the protection of vaccinated pigs from virulent virus infection. The objective of our trials was to compare the intensity of antibody response evoked by pig vaccination with live virus if the virus was implanted in different ways, and by vaccination with inactivated virus emulsified in oil adjuvant. The live vaccine consisted of a suspension of porcine rotavirus, strain OSU/6, cultivated in MA-104 culture medium with the content of 10(7) TKID50.ml-1, the inactivated vaccine was the identical virus suspension inactivated by an addition of 0.2% formaldehyde during 24 hours at a temperature of 37 degrees C, emulsified in oil adjuvant by means of an ULTRATURAX equipment at a 4:1 ratio.(ABSTRACT TRUNCATED AT 250 WORDS)

Adjuvants, Immunologic↗