Title : Development of multivalent anti-urogenital chlamydia vaccine
Abstract:
Over 130 million cases of urogenital chlamydial infection are globally recorded yearly, making it one of the top sexually transmitted diseases among the 15- 45-year age group. This infection results in severe conditions like ectopic pregnancy, infertility, and pelvic inflammatory diseases if not treated. Despite antibiotic treatment, reinfections are often recorded. Thus, vaccine development against Chlamydia trachomatis (C. t.) infection is urgently required. Because of the antigenic variation of C. t., the major outer membrane protein (MOMP), a key factor for its pathogenicity, has diverse serovars, making it difficult to develop an efficient vaccine against it. Currently, the FDA has not authorized any C. t. vaccine, and the main challenge is the generation of efficient vaccines that cover urogenital C. t. serovars.
It is known that urogenital C. t, including serovars (D, E, F, G), shares variable domains VD1 and VD4, which are surface-exposed sequences, making them important targets for neutralizing antibodies. In our study, the VD4D-G sequence was fused with the DC-targeting domain of the Ebola glycoprotein to make the Ebo-VD4D-G immunogen, and it was co-expressed with VD1-4D-G and/or MOMPF immunogens in a recombinant vesicular stomatitis virus (rVSV) vector as anti-urogenital C. t vaccine candidates. The immunogenicity results have clearly shown that immunization with each of these vaccines has induced significantly high levels of antibodies against C.t. MOMP protein derived from serovar D and L. Furthermore, in vitro analyses revealed that the vaccine-induced mouse sera exhibited some levels of ADCC and neutralizing activity. More detailed information will be presented at the conference.
