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.
Coulson
B S
BS
Department of Gastroenterology, Royal Children's Hospital, Parkville, Victoria, Australia.
D000818:Animals; D000911:Antibodies, Monoclonal; D002648:Child; D000939:Epitopes; D005243:Feces / Q000382:microbiology; D006801:Humans; D007124:Immunoenzyme Techniques; D007231:Infant, Newborn; D051379:Mice; D008807:Mice, Inbred BALB C; D012401:Rotavirus / Q000145:classification*; D012703:Serotyping / Q000379:methods*; D013047:Specific Pathogen-Free Organisms
D000911:Antibodies, Monoclonal; D000939:Epitopes