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

@entity19 @entity327 @entity166 @entity1729
Nasal vaccination is an effective therapeutic regimen for preventing @entity1729 , while DNA vaccines represent a new approach for controlling @entity166 . Here, we examined the efficacy of nasally administered DNA vaccine on @entity1729 . A DNA plasmid encoding the P6 outer membrane protein of nontypeable @entity327 (NTHi) was constructed. @entity19 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 @entity19 . 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.
