R. Verma, R. Sahu, S. Dixit, S.R. Singh, V.A. Dennis
Alabama State University,
Keywords: Chlamydia muridarum, nanovaccine, MOMP (Major Outer Membrane Protein), PLA-PEG [poly(lactic acid)-poly(ethylene glycol)], antibodies
Summary:The rising concerns relating to the failure of public health programs, relying mostly on antibiotic treatments to control the plethora of disease manifestations caused by Chlamydia trachomatis in humans, strongly begs the urgency for an efficacious mucosal vaccine against the pathogen. We have developed a Chlamydia nanovaccine by encapsulating M278 [a peptide derived from the major outer membrane protein (MOMP)] within poly(lactic acid)-poly(ethylene glycol) nanoparticles (named PLA-PEG-M278) that provided partial protection in mice against a C. muridarum (Cm) challenged infection. Here our goal is to assess the protective systemic and mucosal antibody responses provided by the PLA-PEG-M278 nanovaccine in immunized female BALB/c mice challenged with live Cm. Our results reveal that the PLA-PEG-M278 nanovaccine mice produced higher serum and vaginal wash M278-specific IgG, IgG1, IgG2b and IgA antibodies as compared to bare M278 mice. The nanovaccine mice produced more Th2 (IgG1) than Th1 (IgG2b) antibodies, suggesting more of a dominant Th2 antibody response. A notable finding was that the nanovaccine mice produced heightened serum and vaginal wash MOMP-specific IgG, IgG1, IgG2b and IgA antibodies after a live bacterial challenged infection. Together, the PLA-PEG-M278 nanovaccine induced systemic and mucosal IgA antibody responses that may play essential roles in protecting mice against a vaginal chlamydial infection. Our findings are novel and provide an initial step in developing a mucosal nanovaccine against Chlamydia.