Induction of Protection in Mice against a Chlamydia muridarum Respiratory Challenge by a Vaccine Formulated with the Major Outer Membrane Protein in Nanolipoprotein Particles

Abstract

Chlamydia trachomatis is a sexually transmitted bacterium that infects over 130 million individuals worldwide annually. To implement a vaccine, we developed a cell-free co-translational system to express the Chlamydia muridarum major outer membrane protein (MOMP). This approach uses a nanolipoprotein particles (tNLP) made from ApoA1 protein, amphiphilic telodendrimer and lipids that self-assemble to form 10–25 nm discs. These tNLP provide a protein-encapsulated lipid support to solubilize and fold membrane proteins. The cell-free system co-translated MOMP and ApoA1 in the presence of telodendrimer mixed with lipids. The MOMP-tNLP complex was amenable to CpG and FSL-1 adjuvant addition. To investigate the ability of MOMP-tNLP+CpG+FSL-1 to induce protection against an intranasal (i.n.) C. muridarum challenge, female mice were vaccinated intramuscularly (i.m.) or i.n. and i.m. simultaneously 4 weeks apart. Following vaccination with MOMP-tNLP+CpG+FSL-1, mice mounted significant humoral and cell-mediated immune responses. Following the i.n. challenge, mice vaccinated with MOMP-tNLP+CpG+FSL-1 i.n. + i.m. group were protected as determined by the percentage change in body weight and by the number of C. muridarum inclusion forming units (IFU) recovered from the lungs. To our knowledge, this is the first time a MOMP-based vaccine formulated in tNLP has been shown to protect against C. muridarum.

Evaluation in mice of cell-free produced CT584 as a Chlamydia vaccine antigen

“…Demonstrably, pilot studies generating an on-demand vaccine against Francisella tularensis have been performed 40 . Due to the inherent flexibility of CFPS systems, it is also possible to produce and solubilize even challenging chlamydial antigens, such as the integral membrane protein MOMP, for immunization studies where it was able to generate a protective response in mice 41 , 42 . Taking advantage of this flexibility, we used CFPS to produce and characterize the effects of a T3SS protein on protection against Cm infection.…”

“…CT584-specific antibody titers were quantified by ELISA as previously described 42 . Briefly, sera from PBS or sham immunized mice were used as negative controls.…”

Effects of prime-boost strategies on the protective efficacy and immunogenicity of a PLGA (85:15)-encapsulated Chlamydia recombinant MOMP nanovaccine

“…Serum antibody-mediated Chlamydia neutralization in vitro is an important tool to predict the effectiveness of a Chlamydia vaccine (de la Maza et al 2017 ). There are multiple reports indicating that promising Chlamydia vaccine candidates induce neutralizing antibodies (Olsen et al 2021 , Tifrea et al 2021 , Zuo et al 2021 ). Our results show that the levels of EB neutralization enhanced after the Cm intravaginal challenge, which are similar to our previous studies (Verma et al 2018 , Sahu et al 2021 ).…”

Cell-free Scaled Production and Adjuvant Addition to a Recombinant Major Outer Membrane Protein from <em>Chlamydia muridarum</em> for Vaccine Development

“…We have previously published on using cell-free expression to produce membrane proteins embedded within NLPs particles with greater heterogeneity and lower solubility. 4 Additionally, the immunogenicity of MOMP-telodendrimer particles is unclear compared to MOMP-tNLP particles 6 .…”