Nasal immunization induces Haemophilus influenzae-specific Th1 and Th2 responses with mucosal IgA and systemic IgG antibodies for protective immunity.

:To determine the efficacy of a mucosal vaccine against nontypeable Haemophilus influenzae (NTHi), mice were immunized nasally, orally, intratracheally, or intraperitoneally with NTHi antigen together with cholera toxin. Antigen-specific IgA antibody titers in nasal washes and the numbers of antigen-specific IgA-producing cells in nasal passages showed the greatest increases in mice immunized nasally. Cytokine analysis showed that interferon-gamma, interleukin (IL)-2, IL-5, IL-6, and IL-10 were induced by nasal immunization, suggesting that Th2- and Th1-type cells were generated. Furthermore, bacterial clearance of a homologous strain of NTHi from the nasal tract was significantly enhanced in the nasal immunization group. These findings suggest that nasal immunization is an effective vaccination regimen for the induction of antigen-specific mucosal immune responses, which reduce the colonization of NTHi in the nasal tract.

Kurono Y ，Yamamoto M ，Fujihashi K ，Kodama S ，Suzuki M ，Mogi G ，McGhee JR ，Kiyono H ... -  《JOURNAL OF INFECTIOUS DISEASES》

Nasal immunization with plasmid DNA encoding P6 protein and immunostimulatory complexes elicits nontypeable Haemophilus influenzae-specific long-term mucosal immune responses in the nasopharynx.

Nasal vaccination is an effective therapeutic regimen for preventing upper respiratory infection, while DNA vaccines represent a new approach for controlling infectious diseases. Here, we examined the efficacy of nasally administered DNA vaccine on upper respiratory infections. A DNA plasmid encoding the P6 outer membrane protein of nontypeable Haemophilus influenzae (NTHi) was constructed. Mice were immunized 3 times intranasally with the DNA plasmid and Matrix-M, an immunostimulatory complex adjuvant. P6-specific immune responses were examined using purified P6 protein. Nasal-associated lymphoid tissue (NALT) CD4(+) T cells were purified and incubated with feeder cells in the presence of P6, and the expression of cytokine mRNA was examined. In addition, NTHi challenges were performed and the level of NTHi was quantified in nasal washes. P6-specific nasal wash IgA and serum IgG were elevated following immunization with the DNA plasmid and Matrix-M. The number of specific IgA-producing cells increased in the nasal passages of the immunized mice. In addition to Th1 and Th2 cytokine expression, IL-17 was detected in P6-specific NALT CD4(+) T cells. Moreover, DNA vaccination enhanced bacterial clearance. These findings suggest that a successful DNA vaccination protocol has been developed for inducing in vivo immune responses against NTHi. Nasal vaccination with P6 DNA vaccine and Matrix-M might be a new effective regimen for the induction of specific protective immunity in the upper respiratory tract.

Kodama S ，Hirano T ，Noda K ，Umemoto S ，Suzuki M ... -  《-》

Th17 cells contribute to nontypeable Haemophilus influenzae-specific protective immunity induced by nasal vaccination with P6 outer membrane protein and α-galactosylceramide.

Nasal vaccination is an effective therapeutic means of preventing upper respiratory infection. Recently, nasal vaccination with P6 outer membrane protein of nontypeable Haemophilus influenzae (NTHi) and alpha-galactosylceramide (α-GalCer) was reported to induce NTHi-specific protective immunity. The present study investigated the role of the Th17 cells induced by nasal vaccination. Mice were immunized with P6 and α-GalCer, and their P6-specific immune responses were examined. Cytokine-producing cells were analyzed by flow cytometry, and expression of cytokines in P6-specific CD4+ T cells was determined by reverse transcription-polymerase chain reaction. Bacterial challenges were performed with live NTHi. To examine the role of Th17 cells, bacterial clearance was also evaluated after interleukin (IL)-17 neutralization. P6-specific nasal wash immunoglobulin (Ig) A and serum IgG were increased after immunization with P6 and α-GalCer. Specific IgA-producing cells increased markedly in the nasal passages (NPs) of the immunized mice. In addition to P6-specific Th1 and Th2 cells, IL-17-producing Th17 cells were induced in the NPs and spleen. Bacterial clearance was enhanced by nasal vaccination. Interestingly, impaired NTHi clearance was shown after IL-17 neutralization. These findings suggest that nasal vaccination with P6 and α-GalCer is an effective regimen for the induction of NTHi-specific protective immunity in the upper respiratory tract. In addition to antigen-specific secretory-IgA, specific Th17 cells induced by nasal vaccination contribute to protection against NTHi.

Noda K ，Kodama S ，Umemoto S ，Nomi N ，Hirano T ，Suzuki M ... -  《-》

Nasal vaccination with CpG oligodeoxynucleotide induces protective immunity against non-typeable Haemophilus influenzae in the nasopharynx.

Abe N ，Kodama S ，Hirano T ，Eto M ，Suzuki M ... -  《LARYNGOSCOPE》

A recombinant P4 protein of Haemophilus influenzae induces specific immune responses biologically active against nasopharyngeal colonization in mice after intranasal immunization.

Hotomi M ，Ikeda Y ，Suzumoto M ，Yamauchi K ，Green BA ，Zlotnick G ，Billal DS ，Shimada J ，Fujihara K ，Yamanaka N ... -  《VACCINE》