Secretory IgA antibodies provide cross‐protection against infection with different strains of influenza B virus

Abstract

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.

Oral Fluids as a Live-Animal Sample Source for Evaluating Cross-Reactivity and Cross-Protection following Intranasal Influenza A Virus Vaccination in Pigs

“…Cross-reactive IAV-specific IgA in NW following LAIV vaccination has been shown to correlate with improved heterologous cross-protection in humans and in animal models of human IAV infection (26,65,66). Given the reductions in heterologous virus nasal shedding and in measureable IAV-specific IgA levels in mucosal samples prechallenge (42 dpv), we evaluated the association of cross-reactive mucosal IgA in immunized pigs with the level of cross-protection observed.…”

A Novel Subnucleocapsid Nanoplatform for Mucosal Vaccination against Influenza Virus That Targets the Ectodomain of Matrix Protein 2

“…administration of live or inactivated influenza vaccines is known to favor cross-protection against heterotypic virus strains in relationship with the induction of secretory IgA (sIgA) in the respiratory tract (48,49). Accordingly, influenza VLPs formed by HA, NA, and M1 from the 1918 H1N1 strain were shown to confer cross-protection against H5N1 virus only when delivered i.n., in relation with the induction of local IgA (50).…”

Virus-Like Particle Vaccine Induces Protective Immunity against Homologous and Heterologous Strains of Influenza Virus

“…After the blood samples were allowed to clot and centrifuged, serum samples were collected and stored at Ϫ20°C prior to antibody titration. Nasal and tracheal washes and lung samples were collected from individual mice at week 4.5 after the last immunization or on day 4 after a challenge infection (3,33). The whole-lung extracts prepared as homogenates using frosted glass slides were centrifuged at 1,000 rpm for 10 min to collect supernatants.…”