A Comparison Between Recombinant Listeria GAPDH Proteins and GAPDH Encoding mRNA Conjugated to Lipids as Cross-Reactive Vaccines for Listeria, Mycobacterium, and Streptococcus

Abstract

Cross-reactive vaccines recognize common molecular patterns in pathogens and are able to confer broad spectrum protection against different infections. Antigens common to pathogenic bacteria that induce broad immune responses, such as the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of the genera Listeria, Mycobacterium, or Streptococcus, whose sequences present more than 95% homology at the N-terminal GAPDH1−22 peptide, are putative candidates for universal vaccines. Here, we explore vaccine formulations based on dendritic cells (DC) loaded with two molecular forms of Listeria monocytogenes GAPDH (LM-GAPDH), such as mRNA carriers or recombinant proteins, and compare them with the same molecular forms of three other antigens used in experimental vaccines, listeriolysin O of Listeria monocytogeness, Ag85A of Mycobacterium marinum, and pneumolysin of Streptococcus pneumoniae. DC loaded with LM-GAPDH recombinant proteins proved to be the safest and most immunogenic vaccine vectors, followed by mRNA encoding LM-GAPDH conjugated to lipid carriers. In addition, macrophages lacked sufficient safety as vaccines for all LM-GAPDH molecular forms. The ability of DC loaded with LM-GAPDH recombinant proteins to induce non-specific DC activation explains their adjuvant potency and their capacity to trigger strong CD4+ and CD8+ T cell responses explains their high immunogenicity. Moreover, their capacity to confer protection in vaccinated mice against challenges with L. monocytogenes, M. marinum, or S. pneumoniae validated their efficiency as cross-reactive vaccines. Cross-protection appears to involve the induction of high percentages of GAPDH1−22 specific CD4+ and CD8+ T cells stained for intracellular IFN-γ, and significant levels of peptide-specific antibodies in vaccinated mice. We concluded that DC vaccines loaded with L. monocytogenes GAPDH recombinant proteins are cross-reactive vaccines that seem to be valuable tools in adult vaccination against Listeria, Mycobacterium, and Streptococcus taxonomic groups.

Immunopeptidomics-based design of mRNA vaccine formulations against Listeria monocytogenes

“…To the best of our knowledge, this is the first report describing an mRNA-based, cell-free vaccine against an intracellular bacterium demonstrating high levels of protection in vaccination-challenge experiments. Previous LNP mRNA vaccines against bacterial pathogens such as Mycobacterium tuberculosis and Group A and B Streptococci showed promising results, but either did not report, or reported only moderate reductions in bacterial burden upon vaccination [46][47][48]120 . Recently, an mRNA vaccine encoding nineteen saliva proteins from Ixodes scapularis (black-legged tick) led to acquired tick resistance and reduced transmission of the Lyme disease agent Borrelia burgdorferi in Guinea pigs, however, in this case the vector instead of the pathogen was targeted by the vaccine 121 .…”

Immunopeptidomics-based design of highly effective mRNA vaccine formulations againstListeria monocytogenes

“…Previous lipid nanoparticle mRNA vaccines against bacterial pathogens such as Mycobacterium tuberculosis and Group A and B Streptococci showed promising results, but either did not report, or reported only moderate reductions in bacterial burden upon vaccination. [46][47][48]121 . Recently, an mRNA vaccine encoding nineteen saliva proteins from Ixodes scapularis (black-legged tick) led to acquired tick resistance and reduced transmission of the Lyme disease agent Borrelia burgdorferi in Guinea pigs, however, in this case the vector instead of the pathogen was targeted by the vaccine 122 .…”

First computational design using lambda-superstrings and in vivo validation of SARS-CoV-2 vaccine

“…Neutralization COVID-19 IgG antibodies were measured with the cPass™ kit from GenScript supplied by IES Medical (Leioa, Bizkaia, https://www.iesmedical.es ) that measures the percentage of antibodies able to neutralize the SARS-CoV-2 virus in human sera. Antibodies of IgG isotype against the peptides RBD, CoVPSA, or CONT were assessed according to previously reported methods 40 . In brief, ninety-six well plates were coated with the different peptides (RBD and CoVPSA from the Spike protein and CONT from the Lmo2459 virulence factor) at a concentration of 50 µg/mL in carbonate buffer (pH 8.0) at 4ºC overnight, and were then washed and incubated with 1 mg/mL of BSA (fraction V) for blocking non-specific sites.…”