Characterization and Protective Activity of Monoclonal Antibodies Directed against Streptococcus suis Serotype 2 Capsular Polysaccharide Obtained Using a Glycoconjugate

Pathogens

René Roy¹  Jean-Philippe Auger²  Marcelo Gottschalk²  Guillaume Goyette-Desjardins²  Mariela Segura²  Sonia Lacouture² 

[1] Canadian Glycomics Network (GlycoNet), University of Alberta, Edmonton, AB T6G 2G2, Canada;Research Group on Infectious Diseases in Production Animals, Faculty of Veterinary Medicine, University of Montreal, St-Hyacinthe, QC J2S 2M2, Canada;

关键词: Streptococcus suis;    serotype 2;    capsular polysaccharide;    monoclonal antibody;    opsonophagocytosis;   

DOI  :  10.3390/pathogens8030139

来源: DOAJ

【 摘 要 】

Streptococcus suis serotype 2 is an encapsulated bacterium and an important swine pathogen. Opsonizing antibody responses targeting capsular polysaccharides (CPSs) are protective against extracellular pathogens. To elucidate the protective activity of monoclonal antibodies (mAbs) directed against S. suis serotype 2 CPS, mice were immunized with a serotype 2 CPS-glycoconjugate and three hybridomas were isolated; of which, two were murine IgMs and the other a murine IgG1. Whereas the IgMs (mAbs 9E7 and 13C8) showed different reactivity levels with S. suis serotypes 1, 1/2, 2 and 14, the IgG1 (mAb 16H11) was shown to be serotype 2-specific. All mAbs targeted the sialylated chain of the CPSs. Using an opsonophagocytosis assay, the IgMs were opsonizing towards the S. suis serotypes to which they cross-react, while the IgG1 failed to induce bacterial elimination. In a model of mouse passive immunization followed by a lethal challenge with S. suis serotype 2, the IgG1 and IgM cross-reacting only with serotype 14 (mAb 13C8) failed to protect, while the IgM cross-reacting with serotypes 1, 1/2, and 14 (mAb 9E7) was shown to be protective by limiting bacteremia. These new mAbs show promise as new S. suis diagnostic tools, as well as potential for therapeutic applications.

【 授权许可】

Unknown