Sapporo-like human caliciviruses are genetically and antigenically diverse.
The Sapporo-like human caliciviruses (HuCVs) comprise one of three genogroups of HuCVs associated with acute gastroenteritis. Phylogenetic analysis has shown that Sapporo-like HuCVs are related more closely to animal caliciviruses than to other known HuCVs. We produced 3.2 kb cDNA fragments from the 3' end to three Sapporo-like HuCVs that were associated with acute gastroenteritis in children (Houston/86, Houston/90, and London/92). Sequence analysis of the 3.2 kb cDNAs showed that two of the three viruses had a genomic organization similar to that of other Sapporo-like strains and the third strain (London/92) lacked an open reading frame overlapping the 5' end of the capsid gene. Alignment of the capsid sequences of these three strains showed 44-78% amino acid identity among the three strains. Phylogenetic analysis of the aligned sequences indicated the three strains are related but each belongs to a distinct genetic cluster. The genetic differences are associated with antigenic differences in that an enzyme immune assay (EIA) specific for the prototype Sapporo/82 strain detected the Houston/86 strain, but not the Houston/90 and London/92 strains. In vitro transcription and translation of viral cDNA containing the predicted capsid gene of Houston/90 resulted in a protein of 63 K, which is immunoprecipitated by sera from children infected with the strain. Genetically and antigenically distinct strains in the Sapporo-like HuCVs have not been described previously and the occurrence of such diverse strains in the same community likely increases the importance of these strains as a cause of illness in children.
Jiang
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X
Center for Pediatric Research, Children's Hospital of The King's Daughters, Eastern Virginia Medical School, Norfolk, USA.
Cubitt
W D
WD
Berke
T
T
Zhong
W
W
Dai
X
X
Nakata
S
S
Pickering
L K
LK
Matson
D O
DO
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral / Q000276:immunology*; D002139:Caliciviridae / Q000145:classification / Q000235:genetics* / Q000276:immunology*; D017250:Caliciviridae Infections / Q000821:virology; D002213:Capsid / Q000737:chemistry / Q000235:genetics*; D002648:Child; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005759:Gastroenteritis / Q000821:virology; D016679:Genome, Viral; D006801:Humans; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment
D000956:Antigens, Viral; D018076:DNA, Complementary