| Autor: |
Nonne F; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Molfetta M; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Nappini R; GSK Vaccines Institute for Global Health, 53100 Siena, Italy.; Department of Life Science, University of Trieste, 34127 Trieste, Italy., La Guidara C; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Di Benedetto R; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Mfana S; Department of Chemistry, University of Cape Town, Cape Town 7700, South Africa., Bellich B; Department of Advanced Translational Diagnostics, Institute for Maternal and Child Health, IRCCS 'Burlo Garofolo', 34137 Trieste, Italy., Raso MM; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Gasperini G; GSK, 53100 Siena, Italy., Alfini R; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Cescutti P; Department of Life Science, University of Trieste, 34127 Trieste, Italy., Berlanda Scorza F; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Ravenscroft N; Department of Chemistry, University of Cape Town, Cape Town 7700, South Africa., Micoli F; GSK Vaccines Institute for Global Health, 53100 Siena, Italy., Giannelli C; GSK Vaccines Institute for Global Health, 53100 Siena, Italy. |
| Abstrakt: |
Klebsiella pneumoniae (Kp) is a Gram-negative bacterium, and a leading cause of neonatal sepsis in low- and middle-income countries, often associated with anti-microbial resistance. Two types of polysaccharides are expressed on the Kp cell surface and have been proposed as key antigens for vaccine design: capsular polysaccharides (known as K-antigens, K-Ags) and O-antigens (O-Ags). Historically, Kp has been classified using capsule serotyping and although 186 distinct genotypes have been predicted so far based on sequence analysis, many structures are still unknown. In contrast, only 11 distinct OAg serotypes have been described. The characterization of emerging strains requires the development of a high-throughput purification method to obtain sufficient K- and O-Ag material to characterize the large collection of serotypes and gain insight on structural features and potential cross-reactivity that could allow vaccine simplification. Here, this was achieved by adapting our established method for the simple purification of O-Ags, using mild acetic acid hydrolysis performed directly on bacterial cells, followed by filtration and precipitation steps. The method was successfully applied to purify the surface carbohydrates from different Kp strains, thereby demonstrating the robustness and general applicability of the purification method developed. Further, antigen characterization showed that the purification method had no impact on the structural integrity of the polysaccharides and preserved labile substituents such as O-acetyl and pyruvyl groups. This method can be further optimized for scaling up and manufacturing to support the development of high-valency saccharide-based vaccines against Kp. |
