Cell-free screening, production and animal testing of a STI-related chlamydial major outer membrane protein supported in nanolipoproteins.
Vaccine development against Chlamydia, a prevalent sexually transmitted infection (STI), is imperative due to its global public health impact. However, significant challenges arise in the production of effective subunit vaccine based on recombinant protein antigens, particularly with membrane proteins like the Major Outer Membrane Protein (MOMP). Cell-free protein synthesis (CFPS) technology is an attractive method to address these challenges as a method of high-throughput membrane protein and protein complex production coupled with nanolipoprotein particles (NLPs). NLPs provides a supporting scaffold while allowing easy adjuvant addition during formulation. Over the last decade we have been working toward production and characterization of MOMP-NLP complexes for vaccine testing. The work presented here highlights the expression and biophysical analyses, including transmission electron microscopy (TEM) and dynamic light scattering (DLS), confirm formation and functionality of MOMP-NLP complexes for use in animal studies. Moreover, immunization studies in preclinical models compare the past and present protective efficacy of MOMP-NLP formulations, particularly when co-adjuvanted with CpG and FSL1. Ex vivo assessments further highlight the immunomodulatory effects of MOMP-NLP vaccinations, emphasizing their potential in eliciting robust immune responses. However, further research is warranted to further optimize vaccine formulations, validate efficacy against Chlamydia trachomatis, and better understand underlying mechanisms of immune response.