Secretory IgA antibodies provide cross-protection against infection with different strains of influenza B virus.
This study examined whether secretory IgA (S-IgA) antibodies (Abs) could confer cross-protective immunity against infection with influenza B viruses of antigenically distinct lineages. Wild-type or polymeric Ig receptor (pIgR)-knockout (KO) mice were immunized by infection with different B viruses or by intranasal (i.n.) administration with different inactivated vaccines. Four weeks later mice were challenged with either the B/Ibaraki/2/85 virus, representative of the B/Victoria/2/87 (B/Victoria)-lineage, or B/Yamagata/16/88 virus, representative of the B/Yamagata-lineage. Three days after challenge, nasal wash and serum specimens were assayed for IgA and IgG Abs specific for challenge viral antigens and for protection against challenge viruses. In wild-type mice, B/Ibaraki (or B/Yamagata) cross-reactive IgA Abs were detected at higher levels when infected or immunized with homologous-lineage viruses and at lower levels when infected or immunized with heterologous-lineage viruses. There was a correlation between the amount of nasal cross-reactive IgA Ab and the efficacy of cross-protection with a homologous-lineage virus. In mice lacking the pIgR, nasal cross-protective IgA Abs were only marginally detected in vaccinated mice and an accumulation of IgA in the serum was observed. This reduction of nasal IgA was accompanied by inefficient cross-protection against the B/Ibaraki (or B/Yamagata) virus infection. These results suggest that challenge viral-antigen cross-reactive S-IgA in nasal secretions induced by i.n. infection or vaccination is involved in providing cross-protection against challenge infection with virus within either the B/Victoria- or B/Yamagata-lineage.
Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan. asahi@nih.go.jp
Yasuko
Y
Asahi-Ozaki
Tomoki
T
Yoshikawa
Yoichiro
Y
Iwakura
Yujiro
Y
Suzuki
Shin-Ichi
S
Tamura
Takeshi
T
Kurata
Tetsutaro
T
Sata
D000818:Animals; D005260:Female; D006801:Humans; D007071:Immunoglobulin A, Secretory / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D009981:Influenza B virus / Q000145:classification* / Q000235:genetics / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology* / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D019056:Receptors, Polymeric Immunoglobulin / Q000235:genetics; D015164:Vaccines, Inactivated / Q000276:immunology
D007071:Immunoglobulin A, Secretory; D007074:Immunoglobulin G; D007252:Influenza Vaccines; D019056:Receptors, Polymeric Immunoglobulin; D015164:Vaccines, Inactivated