Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Rotavirus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed1981

A prospective clinical study of rotavirus diarrhoea in young children.

The clinical and laboratory features of 96 children aged 6 to 36 months with acute rotavirus diarrhoea were compared to findings on 63 children of the same age with acute non-rotavirus diarrhoea. Of the rotavirus-associated cases 80% occurred between January and June. In general, the diarrhoea was more severe in these patients than in the others, but no difference was seen in duration of symptoms. Clinical features characteristic of rotavirus-associated cases included: dehydration and acidosis upon admission, vomiting, fever, neutropenia and sugar in the stools (Clinitest greater than or equal to 0.5%). In contrast, no difference was seen in the occurrence of respiratory symptoms (53% in the rotavirus, 62% in the non-rotavirus group), or in the presence of mucus strands, occult blood or leucocytes in stools. A combination of the above criteria may be helpful in the presumptive diagnosis of rotavirus diarrhoea.

Adolescent↗
PubMed2001

[Evaluation of immunochromatography based rapid detection kit of rotavirus and adenovirus].

We investigated the usefulness of Rapidtesta Rota-Adeno (Daiichi Pure Chemicals Co., Ltd., Japan) for rapid detection of group A rotavirus and adenovirus simultaneously using immunochromatography with clinical samples. In investigation of the reaction of the kit to 5 strains of group A rotavirus, 13 strains of adenovirus and other intestinal viruses, specific lines were formed in red to group A rotavirus and blue to adenovirus. No cross reaction was observed with other intestinal virus. In measurement of detection limit, group A rotavirus (SA11) was detected at 10(4.4)TCID50/ml, serotype 3 adenovirus at 10(4.45)TCID50/ml. The detection limit of the kit was similar to other immunochromatographic assay or enzyme immnoassay kits and approximately 10 times higher than that of kits using latex agglutination test. In comparison with other testing kits in clinical samples, the concordance with other immunochromatographic assay was 99.2% (121/122) in group A rotavirus and 98.6% (138/140) in adenovirus. The rate of concordance with latex agglutination test kit was 94.5% (69/73) in group A rotavirus and 92.3% (84/91) in adenovirus. The kit had high rates of concordance with other immunochromatographic assay kits and higher virus detection rates than those of latex agglutination test kits. Rapidtesta Rota-Adeno is able to detect group A rotavirus and adenovirus simply and rapidly. In addition, the two kinds of virus can be easily differentiated by color difference in reaction lines, suggesting that the kit is useful in clinical diagnosis.

Adenoviridae↗
PubMed2006

Molecular characterization of novel G5 bovine rotavirus strains.

Group A rotaviruses are a major cause of acute gastroenteritis in young children as well as many domestic animals. The rotavirus genome is composed of 11 segments of double-stranded RNA and can undergo genetic reassortment during mixed infections, leading to progeny viruses with novel or atypical phenotypes. The aim of this study was to determine if the bovine group A rotavirus strains KJ44 and KJ75, isolated from clinically infected calves, share genetic features with viruses obtained from heterologous species. All 11 genes sequences of the KJ44 and KJ75 strains were sequenced and analyzed. The KJ44 VP4 had 91.7% to 96.3% deduced amino acid identity to the bovine related P[1] strain, whereas the KJ75 strain was most closely related to the bovine related P[5] strain (91.9% to 96.9% amino acid identity). Both KJ44 and KJ75 strains also contained the bovine related VP3 gene. The remaining 9 segments were closely related to porcine group A rotaviruses. The KJ44 and KJ75 strains showed high amino acid identity to the G5 rotaviruses, sharing 90.4% to 99.0% identity. In addition, these strains belonged to the NSP4 genotype B, which is typical of porcine rotaviruses and subgroup I, with the closest relationship to the porcine JL-94 strain. These results strongly suggest that bovine rotavirus strains with the G5 genotype occur in nature as a novel G genotype in cattle as a result of a natural reassortment between bovine and porcine strains.

Amino Acid Sequence↗
PubMed1982

Comparison of direct and indirect enzyme immunoassays with direct ultracentrifugation before electron microscopy for detection of rotaviruses.

A direct and an indirect enzyme immunoassay (EIA) were evaluated against a standard of electron microscopy after direct ultracentrifugation of the specimen for their performances in detecting rotaviruses. The indirect EIA had variable background activity which influenced test specificity. The indirect EIA control (test system without the detector antibody) plus a regression line (which reflected background noise) improved test specificity. However, the results of direct EIA (Rotazyme; Abbott Laboratories, North Chicago, Ill.) sensitivity (86%) and specificity (96%) were better than those of the indirect EIA in tests on 73 rotavirus-positive and 78 rotavirus-negative specimens. Endpoint titrations of purified SA-11 rotavirus showed greater sensitivity of the direct EIA test. Electron microscopy, performed after direct ultracentrifugation, and direct EIA were approximately 2 log10 more sensitive in the detection of purified SA-11 rotavirus than was electron microscopy with standard methods of unconcentrated specimen preparation. Direct EIA test are potentially sensitive, specific, and practical for the rapid detection of rotaviruses from human clinical specimens. Further studies are needed before EIA methods for detection of human rotaviruses can be equated with the level of reliability of results obtainable with sensitive electron microscopy techniques.

Animals↗
PubMed1984

Rotavirus-specific antibodies in fetal bovine serum and commercial preparations of serum albumin.

Rotavirus-specific antibodies were detected in fetal bovine serum, bovine serum albumin, and human serum albumin by radioimmunoprecipitation with the NCDV strain of bovine rotavirus as the detecting antigen. Fetal bovine sera neutralized bovine rotavirus in a plaque reduction neutralization test to titers of 1:20 or greater. Immunoglobulins purified from fetal bovine serum by protein A-agarose affinity chromatography precipitated rotavirus antigens but did not neutralize bovine rotavirus. Rotavirus antibodies in fetal bovine serum and in purified serum albumin preparations may interfere with diagnostic assays for the detection of rotavirus antigens or antibodies.

Animals↗
PubMed1988

Evaluation of seven immunoassays for detection of rotavirus in pediatric stool samples.

The performance of seven commercially manufactured rotavirus assays was evaluated with 144 pediatric stool specimens and compared with electron microscopy (EM) findings. The four enzyme-linked immunosorbent assays used were Rotazyme II, Pathfinder, IDL rotavirus immunoassay, and Enzygnost (Behring) rotavirus assay. The three latex tests were Meritec rotavirus detection test, Virogen Rotatest, and Bartels rotavirus latex test. Test outcomes were compared with EM on the basis of sensitivity, specificity, positive-negative predictive value, and the kappa statistic. Relative to EM, Meritec had the highest specificity (97%), followed by Virogen (95%), IDL (91%), Pathfinder (85%), Behring (81%), Bartels (72%), and Rotazyme (71%). The sensitivities were as follows: Rotazyme (92%), Pathfinder (89%), Bartels (86%), Virogen (86%), Behring (82%), Meritec (71%), and IDL (75%). Patient age and sex did not influence test results. Owing to the absence of a true standard, the tests were also compared with each other on the basis of the kappa statistic, the frequency of positive test results, and the frequency of samples in which a test differed from all other tests. Using these measures, the assays could be classified into three groups with progressively decreasing utility: group 1 (Virogen, Meritec, IDL, and EM), group 2 (Pathfinder and Behring), and group 3 (Rotazyme and Bartels). Laboratory criteria were also compared. Latex tests were faster and required less equipment than enzyme-linked immunosorbent assays. The Virogen latex assay showed the best overall performance, which made it our choice for rapid and accurate rotavirus diagnosis. However, in children who have gastrointestinal symptoms with negative rotavirus test results, EM will be useful until such time as immunological tests for other enteric viruses are available.

Adolescent↗
PubMed1989

Dot hybridization assay for distinction of rotavirus serotypes.

We have developed a hybridization assay that permits distinction of rotavirus serotypes 1, 2, 3, and 4. The serotype of rotaviruses from stool samples or tissue culture was recognized by hybridization of specific probes to (i) blots of viral double-stranded RNAs electrophoresed in agarose gels (Northern blots) or (ii) heat-denatured double-stranded RNAs directly dotted on nylon membranes. The probes consisted of 32P-labeled cDNA synthesized by reverse transcription of in vitro derived rotavirus mRNA from rotavirus serotypes 1 to 4. To prepare these probes, mRNAs were primed with a 17-mer nucleotide common to all four serotypes whose sequence is complementary to bases 375 to 391 of the rotavirus gene encoding the VP7 glycoprotein (gene 8 or 9 depending on the rotavirus strain). The resulting downstream transcripts encompassed areas of major sequence divergence among the four serotypes. Hybridization at high stringency (50 degrees C, 50% formamide, 4 x SSC [1 x SSC is 0.15 M NaCl plus 0.015 M sodium citrate]) was performed for 16 to 48 h. Autoradiograms of the washed membranes allowed recognition of the rotavirus serotype present in the blotted or dotted specimens since each of them hybridized preferentially to one of the four probes. Twenty-four laboratory specimens and 103 clinical specimens from Washington, D.C., Venezuela, and Chile were "serotyped" with this assay. The results were similar to those obtained with a monoclonal antibody serotyping assay.

Animals↗
PubMed1993

Typing of human rotavirus VP4 by an enzyme immunoassay using monoclonal antibodies.

Two different neutralization specificities exist on the outer capsid of group A rotaviruses. At least seven VP7 (G) antigenic types are distinguishable among human rotaviruses. Four distinct antigenic (P) types of human rotavirus VP4 corresponding to separate rotavirus gene 4 groups have been described. The aim of this study was to identify P types in clinical specimens by developing an enzyme immunoassay, using P-type-specific neutralizing monoclonal antibodies (N-MAbs). Three N-MAbs primarily or solely recognizing each of P types 4, 6, and 8 and binding to VP4 or its subunit VP5* were derived. These N-MAbs served as detector antibodies in an enzyme immunoassay P-typing system similar to that in use for G typing. P-type specificity was highest when the G-type specificity of the capture antiserum was matched to the G type of the rotavirus in the test sample. The method correctly identified the P types of 13 well-characterized, cell culture-adapted human rotaviruses and was used to classify a further six strains. P typing of 118 rotavirus-positive stools gave results consistent with the P type inferred from the G type for 98 (83%) samples. Twelve (10%) of the stools showed no reaction with any N-MAb and eight (7%) samples were untypeable because of cross-reactivity between N-MAbs or high background readings. This P-typing enzyme immunoassay system is economical and amenable to large-scale use in epidemiological studies. Its use will facilitate assessment of the distribution of P types worldwide and of the role of VP4 in eliciting protective immune responses.

Animals↗
PubMed1993

Distribution of VP4 gene alleles in human rotaviruses by using probes to the hyperdivergent region of the VP4 gene.

The rotavirus VP4 protein elicits the production of neutralizing antibodies and is known to play a role in inducing resistance to disease. At least five human rotavirus VP4 gene alleles have been described on the basis of antigenic polymorphism and/or nucleotide sequence differences. In the present study, we developed cDNA probes directed at the hyperdivergent region of the VP4 gene of the five described human rotavirus VP4 alleles (Wa, DS1, M37, AU228, and 69M) and used them in hybridization assays with human rotavirus strains from Latin America and Europe to determine the distribution of the VP4 gene alleles in nature. The Wa-like allele was detected most frequently, occurring in 57% of the 402 rotavirus strains tested, and the DS1-like allele was the next most common, occurring in 14% of the strains tested. The M37- and AU228-like alleles were detected in only 4 and 3% of the rotavirus strains tested, respectively, whereas the 69M-like VP4 gene allele was not detected. Several rotavirus strains from Europe did not react with any of the VP4 gene probes, although they did hybridize to a probe generated from a representative strain from the group. These data indicate the global distribution of various VP4 gene alleles and raise the possibility that other, unrecognized human VP4 alleles exist in nature because almost one-fourth of the strains could not be classified into any of the established VP4 groups.

Alleles↗
PubMed2002

Detection and genotyping of human group A rotaviruses by oligonucleotide microarray hybridization.

A rapid and reliable method for the identification of five clinically relevant G genotypes (G1 to G4 and G9) of human rotaviruses based on oligonucleotide microarray hybridization has been developed. The genotype-specific oligonucleotides immobilized on the surface of glass slides were selected to bind to the multiple target regions within the VP7 gene that are highly conserved among individual rotavirus genotypes. Rotavirus cDNA was amplified in a PCR with primers common to all group A rotaviruses. A second round of nested PCR amplification was performed in the presence of indodicarbocyanine-dCTP and another pair of degenerate primers also broadly specific for all genotypes. The use of one primer containing 5'-biotin allowed us to prepare fluorescently labeled single-stranded hybridization probe by binding of another strand to magnetic beads. The identification of rotavirus genotype was based on hybridization with several individual genotype-specific oligonucleotides. This approach combines the high sensitivity of PCR with the selectivity of DNA-DNA hybridization. The specificity of oligonucleotide microchip hybridization was evaluated by testing 20 coded rotavirus isolates from different geographic areas for which genotypes were previously determined by conventional methods. Analysis of the coded specimens showed that this microarray-based method is capable of unambiguous identification of all rotavirus strains. Because of the presence of random mutations, each individual virus isolate produced a unique hybridization pattern capable of distinguishing different isolates of the same genotype and, therefore, subgenotype differentiation. This strain information indicates one of several advantages that microarray technology has over conventional PCR techniques.

Antigens, Viral↗
PubMed2007

Role of interferon regulatory factor 3 in type I interferon responses in rotavirus-infected dendritic cells and fibroblasts.

The main pathway for the induction of type I interferons (IFN) by viruses is through the recognition of viral RNA by cytosolic receptors and the subsequent activation of interferon regulatory factor 3 (IRF-3), which drives IFN-alpha/beta transcription. In addition to their role in inducing an antiviral state, type I IFN also play a role in modulating adaptive immune responses, in part via their effects on dendritic cells (DCs). Many viruses have evolved mechanisms to interfere with type I IFN induction, and one recently reported strategy for achieving this is by targeting IRF-3 for degradation, as shown for rotavirus nonstructural protein 1 (NSP1). It was therefore of interest to investigate whether rotavirus-exposed DCs would produce type I IFN and/or mature in response to the virus. Our results demonstrate that IRF-3 was rapidly degraded in rotavirus-infected mouse embryonic fibroblasts (MEFs) and type I IFN was not detected in these cultures. In contrast, rotavirus induced type I IFN production in myeloid DCs (mDCs), resulting in their activation. Type I IFN induction in response to rotavirus was reduced in mDCs from IRF-3(-/-) mice, indicating that IRF-3 was important for mediating the response. Exposure of mDCs to UV-treated rotavirus induced significantly higher type I IFN levels, suggesting that rotavirus-encoded functions also antagonized the response in DCs. However, in contrast to MEFs, this action was not sufficient to completely abrogate type I IFN induction, consistent with a role for DCs as sentinels for virus infection.

Animals↗
PubMed1989

Complete nucleotide sequence of the gene encoding VP4 of a human rotavirus (strain K8) which has unique VP4 neutralization epitopes.

In our previous study (K. Taniguchi, Y. Morita, T. Urasawa, and S. Urasawa, J. Virol. 62:2421-2426, 1987) in which the cross-reactive neutralization epitopes on VP4 of human rotaviruses were analyzed, one strain, K8, was found to bear unique VP4 neutralization epitopes. This strain, which belongs to subgroup II and serotype 1, was not neutralized by any of six anti-VP4 neutralizing monoclonal antibodies which reacted with human rotavirus strains of serotypes 1, 3, and 4 or serotypes 1 through 4. We determined the complete nucleotide sequence of the gene encoding VP4 of strain K8 by primer extension. The VP4 gene is 2,359 base pairs in length, with 5' and 3' noncoding regions of 9 and 25 nucleotides, respectively. The gene contains a long open reading frame of 2,325 bases capable of coding for a protein of 775 amino acids. When compared with those of other human rotaviruses, VP4 of strain K8 had an insertion of one amino acid after residue 135, as found in simian rotavirus strains, and in addition, it had a deletion of one amino acid (residue 575). The amino acid homology of VP4 of strain K8 and those of other virulent human rotaviruses was only 60 to 70%. This was unusual, since over 90% VP4 homology has been found among the other virulent human rotavirus strains. In contrast, the VP7 amino acid sequence of the K8 strain was quite similar (over 98% homology) to those of other serotype 1 human rotaviruses. Thus, the K8 strain appears to have a unique VP4 gene previously not described.

Amino Acid Sequence↗
PubMed1990

Rotaviruses specifically bind to the neutral glycosphingolipid asialo-GM1.

Rotaviruses are the major etiologic agents of severe diarrhea in children. Many rotaviruses encode a hemagglutinin which binds to sialic acids. We report that rotaviruses specifically recognize the neutral glycosphingolipid gangliotetraosylceramide (asialo-GM1 or GA1). GA1 resolved by thin-layer chromatography is bound by rotavirus, and binding is blocked by neutralizing rotavirus antiserum. Similar glycosphingolipid structures, such as globoside, gangliotriaosylceramide, and GA1 oxidized with galactose oxidase are ineffective in binding rotavirus. Other enteric viruses also specifically bind GA1. GA1 adsorbed to polystyrene beads inhibits rotavirus replication in vitro (as do anti-GA1 antibodies). The use of orally administered immobilized GA1 or anti-GA1 antibodies may prove useful in preventing or attenuating rotaviral and other enteric viral infections.

Animals↗
PubMed1991

Expression of rotavirus VP2 produces empty corelike particles.

The complete VP2 gene of bovine rotavirus strain RF has been inserted into the baculovirus transfer vector pVL941 under the control of the polyhedrin promoter. Cotransfection of Spodoptera frugiperda 9 cells with wild-type baculovirus DNA and transfer vector DNA led to the formation of recombinant baculoviruses which contain bovine rotavirus gene 2. Infection of S. frugiperda cells with this recombinant virus resulted in the production of a protein similar in size and antigenic properties to the authentic rotavirus VP2. The protein binds double-stranded RNA and DNA in an overlay protein blot assay. Expressed VP2 assembles in the cytoplasm of infected cells in corelike particles 45 nm in diameter. These corelike particles were purified by sucrose gradient centrifugation and found to be devoid of nucleic acid. Coexpression of VP2 and VP6 from heterologous rotavirus strains (bovine and simian) resulted in the formation of single-shelled particles. These results definitively show the existence of an innermost protein shell in rotavirus which is formed independently of other rotavirus proteins. These results have implications for schemes of rotavirus morphogenesis.

Animals↗
PubMed1993

Identification and baculovirus expression of the VP4 protein of the human group B rotavirus ADRV.

A complete cDNA copy of the fourth RNA segment of the human group B rotavirus adult diarrheal rotavirus (ADRV) has been cloned into lambda phage and excised into plasmid pSK Bluescript. Gene segment 4 contains 2,303 bases and encodes one long open reading frame beginning at base 16 and terminating at base 2263. The encoded protein contains 749 amino acids, with a calculated molecular mass of 84.4 kDa and a pI of 6.1. Gene 4 cDNA was inserted into a recombinant baculovirus via homologous recombination. The gene 4 polypeptide migrates at 84 kDa when expressed either by a recombinant baculovirus or in vitro in a rabbit reticulocyte lysate. The gene 4 protein is immunoprecipitable by hyperimmune serum to ADRV, human ADRV convalescent-phase serum, a porcine group B rotavirus infection serum, and a monoclonal antibody made to ADRV virion. Guinea pig hyperimmune serum to the baculovirus-expressed ADRV VP4 protein recognizes virus and immunoprecipitates an 84-kDa protein from in vitro translations of total ADRV mRNA. In addition, the gene 4-encoded protein shares significant amino acid identity and similarity with the group A rotavirus VP4 protein. This information, together with our previous identification of an 84-kDa protein present on iodinated intact virion but not EDTA-treated ADRV, suggests that gene 4 encodes the VP4 protein equivalent present on the outer capsid of ADRV. The ADRV VP4 protein is also 58% identical to the IDIR rat group B rotavirus gene segment 3 protein. The substantial differences between these two group B VP4 proteins suggests that they are distantly related and likely to define two different group B rotavirus VP4 serotypes. The baculovirus-expressed VP4 protein should be useful for developing serotyping reagents and tests for human and animal group B rotaviruses as well as for addressing the role of VP4 in ADRV neutralization.

Amino Acid Sequence↗
PubMed1994

Selection of cold-adapted mutants of human rotaviruses that exhibit various degrees of growth restriction in vitro.

Group A human rotavirus strains D, Wa, DS-1, and P were originally recovered from children with diarrhea. In an attempt to attenuate virulent, wild-type human rotaviruses of major epidemiological importance for use in a live oral vaccine, two reference rotavirus strains, D and DS-1, and two laboratory-generated reassortants, Wa x DS-1 and Wa x P, were subjected to cold adaptation. Collectively, these viruses provide antigenic coverage for both of the clinically important rotavirus VP4 antigens and three of the four important rotavirus VP7 antigens. Mutants of each of these rotaviruses were selected during successive serial passage in primary African green monkey kidney cells at progressively lower suboptimal temperatures (30, 28, and 26 degrees C). The genotype of each mutant appeared to be indistinguishable from that of its wild-type, parental virus. The mutants recovered after 10 serial passages at 30 degrees C exhibited both temperature sensitivity of plaque formation (i.e., a ts phenotype) and the ability to form plaques efficiently at suboptimal temperature (i.e., a cold adaptation [ca] phenotype), in contrast to parental wild-type rotavirus. The succeeding set of 10 serial passages at 28 degrees C selected mutants that exhibited an increased degree of cold adaptation, and three of the mutants exhibited an associated increase in temperature sensitivity. Finally, in the case of three of the strains, the third successive serial passage series, which was performed at 26 degrees C, selected for mutants with an even greater degree of cold adaptation than the previous series and was associated with greater temperature sensitivity in one instance. It appeared that each of the viruses sustained a minimum of four to five mutations during the total selection procedure. The ultimate identification of candidate vaccine viruses that exhibit the desired level of attenuation, immunogenicity, and protective efficacy needed for immunoprophylaxis will require evaluation of these mutants in susceptible humans.

Animals↗
PubMed1997

In vivo and in vitro phosphorylation of rotavirus NSP5 correlates with its localization in viroplasms.

NSP5 (NS26), the product of rotavirus gene 11, is a phosphoprotein whose role in the virus replication cycle is unknown. To gain further insight into its function, we obtained monoclonal antibodies against the baculovirus-expressed protein. By immunoprecipitation and immunoblotting experiments, we showed that (i) NSP5 appears in many different phosphorylated forms in rotavirus-infected cells; (ii) immunoprecipitated NSP5 from rotavirus-infected cells can be phosphorylated in vitro by incubation with ATP; (iii) NSP5, produced either by transient transfection of rotavirus gene 11 or by infection by gene 11 recombinant vaccinia virus or baculovirus, can be phosphorylated in vivo and in vitro; (iv) NSP5 expressed in Escherichia coli is phosphorylated in vitro, and thus NSP5 is a potential protein kinase; and (v) NSP5 forms dimers and interacts with NSP2. The intracellular localization of NSP5 in the course of rotavirus infection and after transient expression in COS7 cells has also been investigated. In rotavirus-infected cells, NSP5 is localized in viroplasms, but it is widespread throughout the cytoplasm of transfected COS7 cells. NSP5 produced by transfected COS7 cells did not acquire the multiphosphorylated forms observed in rotavirus-infected COS7 cells. Thus, there is a tight correlation between the localization of NSP5 in the viroplasms and its protein kinase activity in vivo or in vitro. Our results suggest that cellular or viral cofactors are indispensable to fully phosphorylate NSP5 and to reach its intracellular localization.

Animals↗
PubMed2000

Biochemical characterization of rotavirus receptors in MA104 cells.

We have tested the effect of metabolic inhibitors, membrane cholesterol depletion, and detergent extraction of cell surface molecules on the susceptibility of MA104 cells to infection by rotaviruses. Treatment of cells with tunicamycin, an inhibitor of protein N glycosylation, blocked the infectivity of the SA-dependent rotavirus RRV and its SA-independent variant nar3 by about 50%, while the inhibition of O glycosylation had no effect. The inhibitor of glycolipid biosynthesis d, l-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) blocked the infectivity of RRV, nar3, and the human rotavirus strain Wa by about 70%. Sequestration of cholesterol from the cell membrane with beta-cyclodextrin reduced the infectivity of the three viruses by more than 90%. The involvement of N-glycoproteins, glycolipids, and cholesterol in rotavirus infection suggests that the virus receptor(s) might be forming part of lipid microdomains in the cell membrane. MA104 cells incubated with the nonionic detergent octyl-beta-glucoside (OG) showed a ca. 60% reduction in their ability to bind rotaviruses, the same degree to which they became refractory to infection, suggesting that OG extracts the potential virus receptor(s) from the cell surface. Accordingly, when preincubated with the viruses, the OG extract inhibited the virus infectivity by more than 95%. This inhibition was abolished when the extract was treated with either proteases or heat but not when it was treated with neuraminidase, indicating the protein nature of the inhibitor. Two protein fractions of around 57 and 75 kDa were isolated from the extract, and these fractions were shown to have rotavirus-blocking activity. Also, antibodies to these fractions efficiently inhibited the infectivity of the viruses in untreated as well as in neuraminidase-treated cells. Five individual protein bands of 30, 45, 57, 75, and 110 kDa, which exhibited virus-blocking activity, were finally isolated from the OG extract. These proteins are good candidates to function as rotavirus receptors.

Cholesterol↗