Homologous subcutaneous immunizations of mice with Chlamydia muridarum MOMP nanovaccine induce systemic antibodies eliciting cross-recognition and neutralization of human serovar D elementary bodies
Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B201
Abstract ID: 6025
Presenting Author:
Rajnish Sahu , Post Doctoral Research Associate at Alabama State Univ.
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 vaccine developmental efforts are now utilizing biodegradable nanoparticles with encapsulated antigens. Previously, we showed that the recombinant major outer membrane protein (rMOMP) of C. muridarum (Cm) encapsulated in poly (lactic acid-co-glycolic acid) nanovaccine induced robust humoral responses in homologous subcutaneous (SC) or heterologous intramuscular (IM-p) immunizations in female BALB/c mice. Here, we explored the ability of immunized sera to recognize and neutralize the elementary bodies (EB) of Cm and human serovar D (Ct-D). We employed UV-inactivated EB-specific ELISA to quantify Th1 (IgG2a, IgG2b) and Th2 (IgG1) antibodies. We observed high recognition of Cm specific IgG (8-fold) and isotypes IgG2a (8-fold), IgG2b (32-fold), IgG1 (8-fold) by SC compared to IM-p. We also observed IgG antibodies recognizing Ct-D from immunized sera. Th1/Th2 antibody titer-ratio shows that SC predominantly induced Th1 antibodies recognizing Cm and Ct-D. In vitro EB neutralization shows that the SC and IM-p immunized sera neutralized Cm by 55% and 42%, and Ct-D by 17% and 5%, respectively. Our data show that nanovaccine immunization produced Th1 antibodies against EB, but more importantly, serological recognition and neutralization of the human serovar D.
Homologous subcutaneous immunizations of mice with Chlamydia muridarum MOMP nanovaccine induce systemic antibodies eliciting cross-recognition and neutralization of human serovar D elementary bodies
Category
Poster