Identification of immunodominant linear B-cell epitopes within the major outer membrane protein of <italic>Chlamydia trachomatis</italic>

Abstract

Chlamydia trachomatis is one of the most prevalent sexually transmitted pathogens. Chlamydial major outer membrane protein (MOMP) can induce strong cellular and humoral immune responses in murine models and has been regarded as a potential vaccine candidate. In this report, the amino acid sequence of MOMP was analyzed using computer-assisted techniques to scan B-cell epitopes, and three possible linear B-cell epitopes peptides (VLKTDVNKE, TKDASIDYHE, TRLIDERAAH) with high predicted antigenicity and high conservation were investigated. The DNA coding region for each potential epitope was cloned into pET32a(1) and expressed as TrxHis-tag fusion proteins in Escherichia coli. The fusion proteins were purified by Ni-NTA agarose beads and followed by SDS-PAGE and western blot analysis. We immunized mice with these three fusion proteins. The sera containing anti-epitope antibodies from the immunized mice could recognize C. trachomatis serovars D and E in ELISA. Antisera of these fusion proteins displayed an inhibitory effect on invasion of serovar E by in vitro neutralization assays. In addition, serum samples from convalescent C. trachomatis-infected patients were reactive with the epitope fusion proteins by western blot assay. Our results showed that the epitope sequences selected by bioinformatic analysis are highly conserved C. trachomatis MOMP B-cell epitopes, and could be good candidates for the development of subunit vaccines, which can be used in clinical diagnosis.

Identification and immunogenic potential of B cell epitopes of outer membrane protein OmpF of Aeromonas hydrophila in translational fusion with a carrier protein

“…Other than helping to focus on and thereby narrowing down the specificity of immune response, they also leave room for chimera generation including multiple epitopes from same as well as different and slightly more immunogenic antigens. Though epitopes can be linear or conformational, Zhu et al (2010) have demonstrated the immunodominance of linear epitopes in the past. Therefore, in the present study, we have attempted to predict linear B cell epitopes and analyze their ability to evoke focused immune response.…”

“…Such vaccines provide many advantages over the conventional subunit vaccine approach including instigating a focused immune response, the facility to engineer epitopes in order to customize the type of immune response required, ease of synthetic preparation on a large scale, and the ability to add additional immunogenicity and stability-enhancing groups (carbohydrates, lipids, phosphate groups) (van der Burg et al 2006;Purcell et al 2007). B cell and T cell epitope-based vaccines have been successful against a variety of pathogens including viruses (Depla et al 2008;Sun et al 2013), bacteria (Zhu et al 2010;Xu et al 2011;Li et al 2012), and parasites (Nardin et al 2000).…”

Hepatitis B virus core antigen as a carrier for Chlamydia trachomatis MOMP multi-epitope peptide enhances protection against genital chlamydial infection

“…Several peptides containing both HLA and H2 restricted cytotoxic T-lymphocyte (CTL)/Th epitopes were screened by analyzing the amino acid sequence of Ct MOMP, from which the peptide of MOMP 370-387 containing the reported B-cell epitope (TRLIDERAAH) [ 13 ] was selected to be a candidate for MOMPm (Figure 1A ).…”

Microbial gas vesicles as nanotechnology tools: exploiting intracellular organelles for translational utility in biotechnology, medicine and the environment

“…This recombinant approach was subsequently used to produce GVNPs displaying three different outer-membrane proteins from Chlamydia trachomatis [66]. These proteins were: the major outer membrane protein (MOMP), outer membrane complex B (OcmB) and polymorphic outer-membrane protein D (PompD), each of which have been proposed to have roles in the virulence of C. trachomatis and have been suggested as potential vaccine candidates [67][68][69]. Western blots performed using anti-GvpC and anti-Chlamydia antibodies, as well as sera from patients with Chlamydia infections, were used to detect the presence of MOMP, PompD and OcmB fragments on the surface of the GVNPs [66].…”