The human gut microbiome harbours a complex community of microorganisms which influences human physiology, metabolism, nutrition and immune function . To remain immunologically tolerant to these commensal bacteria and preserve the symbiotic relationship there are many elaborate biochemical mechanisms involved. A well-known mechanism by which bacteria interact with the host is through the lipopolysaccharides (LPS), a key component of the Gram-negative cell wall. LPS is a potent ligand for the host receptor Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD-2) complex . These interactions are vital for the initiation of immune response to pathogens but how LPS from commensal bacteria is recognised is still unclear.
In this communication I will show some results regarding the extraction, purification and structural elucidation, through Mass Spectrometry and NMR techniques, of LPS isolated from the commensal gut bacterial species Veillonella parvula.
Veillonella have been found to play a vital role in poly-microbial infections, specifically in respiratory and oral infections [3,4]. Conversely, alternative research has shown that the LPS isolated from Veillonella shows an inhibitor activity towards pathogenic LPS and can influence the susceptibility of children to allergies and autoimmunity . Since LPS are involved in the interaction between bacteria and the host, an in-depth investigation of the full structure of the LPS from Veillonella is a first but essential step to understand the basis of virulence and symbiotic behaviour of these bacterial species.
- Di Lorenzo, F.; De Castro, C.; Silipo, A.; Molinaro, A. Lipopolysaccharide structures of Gram-negative populations in the gut microbiota and effects on host interactions, FEMS Microbiology Reviews, 2019, fuz002
- Molinaro, A.; Holst, O.; Di Lorenzo, F.; Callaghan, M.; Nurisso, A.; D'Errico, G.; Zamyatina, A.; Peri, F.; Berisio, R.; Jerala, R.; Jiménez-Barbero, J.; Silipo, A. and Martín-Santamaría, S. Chemistry of Lipid A: At the Heart of Innate Immunity, Chem. Eur. J., 2015, 21, 500-519.
- Mashima, I. and Nakazawa, F. Interaction between Streptococcus spp. and Veillonella tobetsuensis in the Early Stages of Oral Biofilm Formation, Journal of Bacteriology, 2015, 197 (13), 2104–2111.
- Pustelny, C., Komor, U., Pawar, V., Lorenz, A., Bielecka, A., Moter, A., Gocht, B., et al., Contribution of Veillonella parvula to Pseudomonas aeruginosa-Mediated Pathogenicity in a Murine Tumor Model System, Infection and Immunity, 2015, 83 (1), 417–429
- Brook, I. Veillonella infections in children, Journal of Clinical Microbiology, 1996, 34 (5), 1283–1285.