<i>Chlamydia muridarum</i>recombinant MOMP nanovaccine induces cross-reactive antibodies against <i>Chlamydia trachomatis</i>human serovars

Abstract Chlamydia trachomatis (CT), caused by various serovars, remains the leading sexually transmitted bacterial infection worldwide. An efficient delivery system is critical to developing whole or subunit vaccines against CT, and some vaccine developmental efforts are targeting biodegradable nanoparticles-based with encapsulated antigens. We developed a nanovaccine employing recombinant major outer membrane protein (rMOMP) of C. muridarum (Cm) in poly(lactic acid-co-glycolic acid) 85/15 (PLGA-rMOMP). previously compared humoral responses two priming routes, subcutaneous (SC) intramuscular (IM-p), followed SC-boosts evaluate rMOMP-specific serum antibodies [IgG2a, IgG2b IgG1] produced PLGA-rMOMP immunization female BALB/c mice. Here we used an elementary body (EB)-specific ELISA investigate ability systemic immunized mice recognize Cm cross-recognize human CT-serovars D, F J. Serum from inoculated PBS PLGA served as negative control. observed high recognition specific total IgG (8-fold) isotypes IgG2a (8-fold), (32-fold), IgG1 SC comparison IM-p immunizations. also recognizing J via both routes. Evaluation Th1 (IgG2a, IgG2b)/Th2 (IgG1) antibody titer ratios revealed that route induced predominantly CT-serovars. Our data show levels Cm, but more importantly, there was robust serological cross-recognition This research supported National Institute Of Allergy And Infectious Diseases Institutes Health under Award Number NIH-R21AI111159, NIH-NIGMS-RISE (1R25GM106995-01) Science Foundation (NSF)-CREST (HRD-1241701) NSF-HBCU-RISE (HRD-1646729) grants.