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 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 ... -  《-》

Nasal vaccination with P6 outer membrane protein and alpha-galactosylceramide induces nontypeable Haemophilus influenzae-specific protective immunity associated with NKT cell activation and dendritic cell expansion in nasopharynx.

The efficacy of alpha-galactosylceramide (alpha-GalCer) as a mucosal adjuvant was examined. Mice were immunized intranasally with nontypeable Haemophilus influenzae (NTHi) P6 protein and alpha-GalCer. P6-specific antibody responses in the form of P6-specific IgA in nasal washes and serum IgG titers were significantly elevated. Splenic CD4(+) T cells expressed P6-specific Th1 and Th2 cytokine mRNA. In addition, NTHi was quantified in nasal washes following NTHi challenges, and the clearance of NTHi from the nasopharynx was also enhanced. These results indicate that alpha-GalCer might be an effective mucosal adjuvant.

Noda K ，Kodama S ，Umemoto S ，Abe 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 single nasal dose of fms-like tyrosine kinase receptor-3 ligand, but not peritoneal application, enhances nontypeable Haemophilus influenzae-specific long-term mucosal immune responses in the nasopharynx.

Nasal vaccination is an effective therapeutic regimen for preventing otitis media. In the development of nasal vaccine, an appropriate adjuvant is required. In the present study, we examined the efficacy of fms-like tyrosine kinase receptor-3 ligand (Flt3L) as a mucosal adjuvant. Flt3L was administered intranasally or peritoneally to mice, which were then immunized intranasally with P6 protein of nontypeable Haemophilus influenzae (NTHi), and P6-specific immune responses were examined. In addition, NTHi challenges were performed and the level of NTHi was quantified in nasal washes. Nasal application of Flt3L induced an increase in the number of dendritic cells in nasal-associated lymphoid tissue. P6-specific nasal wash immunoglobulin (Ig)A and serum IgG titers were elevated significantly after nasal immunization. Enhanced NTHi clearance from the nasopharynx was also observed. The effect of nasal vaccination with P6 combined with nasal Flt3L application was prolonged. These results indicate the potential of Flt3L as an effective mucosal adjuvant and suggest that nasal vaccination with P6 in combination with nasal Flt3L might be an effective regimen for the induction of NTHi-specific protective immunity.

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