title: Humoral immune responses against norovirus infections of children.
abstract: In 2 infants with gastroenteritis associated with Norovirus (NoV), serum immunoglobulin (Ig) G, IgM, IgA, and fecal IgA antibody responses against NoV were examined by enzyme-linked immunosorbent assay using 11 different antigenic and genetic types of NoV virus-like particles expressed in insect cells. These two cases were putative primary single NoV infections, because antibodies against NoVs were not detected in acute-phase serums. In one of two cases, long-term excretion of virus RNA for 33 days was observed. Serum IgG responses demonstrated strong seroresponse to the homologous type, and weak seroresponse to the heterologous types within the genogroup. After more than 2 years, the IgG antibody titer remained high to the homologous type and low to the heterologous type within the genogroup. IgM and IgA were specific to the homologous type. IgM was short lived and the serum IgA antibody titer remained low to the homologous type for a long period. These results improve our understanding of the humoral immune response to NoV infection.
authors.affiliation: Department of Microbiology, Osaka City Institute of Public Health and Environmental Sciences, Tennoji-ku, Osaka, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Iritani
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Seto
authors.forename: Hideji
authors.initials: H
authors.lastname: Hattori
authors.forename: Katsurou
authors.initials: K
authors.lastname: Natori
authors.forename: Naokazu
authors.initials: N
authors.lastname: Takeda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kubo
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Yamano
authors.forename: Minoru
authors.initials: M
authors.lastname: Ayata
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ogura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Seto
mesh_terms: D000914:Antibodies, Viral / Q000097:blood / Q000302:isolation & purification*; D000917:Antibody Formation; D017250:Caliciviridae Infections / Q000097:blood / Q000276:immunology* / Q000821:virology*; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000276:immunology* / Q000821:virology; D006801:Humans; D007070:Immunoglobulin A / Q000302:isolation & purification; D007075:Immunoglobulin M / Q000302:isolation & purification; D007223:Infant; D008297:Male; D029322:Norovirus / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007075:Immunoglobulin M