Microencapsulated IL-12 Drives Genital Tract Immune Responses to Intranasal Gonococcal Outer Membrane Vesicle Vaccine and Induces Resistance to Vaginal Infection with Diverse Strains of Neisseria gonorrhoeae.

An experimental gonococcal vaccine consisting of outer membrane vesicles (OMVs) and microsphere (ms)-encapsulated interleukin-12 (IL-12 ms) induces Th1-driven immunity, with circulating and genital antibodies to Neisseria gonorrhoeae, after intravaginal (i.vag.) administration in female mice, and generates resistance to vaginal challenge infection. Because i.vag. administration is inapplicable to males and may not be acceptable to women, we determined whether intranasal (i.n.) administration would generate protective immunity against N. gonorrhoeae. Female and male mice were immunized i.n. with gonococcal OMVs plus IL-12 ms or blank microspheres (blank ms). Responses to i.n. immunization were similar to those with i.vag. immunization, with serum IgG, salivary IgA, and vaginal IgG and IgA antigonococcal antibodies induced when OMVs were administered with IL-12 ms. Male mice responded with serum IgG and salivary IgA antibodies similarly to female mice. Gamma interferon (IFN-γ) production by CD4