title: Live-attenuated influenza viruses as delivery vectors for Chlamydia vaccines.
abstract: Effective delivery systems are needed to design efficacious vaccines against the obligate intracellular bacterial pathogen, Chlamydia trachomatis. Potentially effective delivery vehicles should promote the induction of adequate levels of mucosal T-cell and antibody responses that mediate long-term protective immunity. Antigen targeting to the nasal-associated lymphoid tissue (NALT) is effective for inducing high levels of specific immune effectors in the genital mucosa, and therefore suitable for vaccine delivery against genital chlamydial infection. We tested the hypothesis that live attenuated influenza A viruses are effective viral vectors for intranasal delivery of subunit vaccines against genital chlamydial infection. Recombinant influenza A/PR8/34 (H1N1) viruses were generated by insertion of immunodominant T-cell epitopes from chlamydial major outer membrane protein into the stalk region of the neuraminidase gene. Intranasal immunization of mice with viral recombinants resulted in a strong T helper 1 (Th1) response against intact chlamydial elementary bodies. Also, immunized mice enjoyed a significant state of protective immunity (P > 0.002) by shedding less chlamydiae and rapidly clearing the infection. Furthermore, a high frequency of Chlamydia-specific Th1 was measured in the genital mucosal and systemic draining lymphoid tissues within 24 hr after challenge of vaccinated mice. Moreover, multiple epitope delivery provided a vaccine advantage over single recombinants. Besides, long-term protective immunity correlated with the preservation of a robustly high frequency of specific Th1 cells and elevated immunoglobulin G2a in genital secretions. Because live attenuated influenza virus vaccines are safe and acceptable for human use, they may provide a new and reliable approach to deliver efficacious vaccines against sexually transmitted diseases.
authors: National Center for Infectious Disease, CDC, Atlanta, GA, USA.
authors: Qing
authors: Q
authors: He
authors: Luis
authors: L
authors: Martinez-Sobrido
authors: Francis O
authors: FO
authors: Eko
authors: Peter
authors: P
authors: Palese
authors: Adolfo
authors: A
authors: Garcia-Sastre
authors: Deborah
authors: D
authors: Lyn
authors: Daniel
authors: D
authors: Okenu
authors: Claudiu
authors: C
authors: Bandea
authors: Godwin A
authors: GA
authors: Ananaba
authors: Carolyn M
authors: CM
authors: Black
authors: Joseph U
authors: JU
authors: Igietseme
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage* / Q000276:immunology; D002690:Chlamydia Infections / Q000276:immunology / Q000517:prevention & control*; D002692:Chlamydia trachomatis / Q000276:immunology*; D016503:Drug Delivery Systems / Q000379:methods; D005260:Female; D005822:Genetic Vectors; D005831:Genital Diseases, Female / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control; D005836:Genitalia, Female / Q000276:immunology; D018928:Immunity, Mucosal; D016056:Immunodominant Epitopes / Q000008:administration & dosage / Q000276:immunology; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D009092:Mucous Membrane / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D014611:Vaccination / Q000379:methods; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology
chemical_list: D001428:Bacterial Vaccines; D016056:Immunodominant Epitopes; D014614:Vaccines, Synthetic