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Mariela Segura

Assistant Professor

School of Veterinary Medicine

Campus de St-Hyacinthe
3200, rue Sicotte
St-Hyacinthe (Québec)
J2S 2M2

Tel.: 450 773-8521, local 0080
Fax: 450 778-8108
Email: mariela [dot] segura [at] umontreal [dot] ca

 

Research interests


Major interest:

Study the cellular and molecular basis of innate and adaptive immunity to capsular and/or exo-polysaccharides of extracellular bacteria and the role of dendritic cells (DCs) in orchestrating these responses.

Specific themes:

  • Group B Streptococcus (GBS): a model for the study of encapsulated bacteria:
  • Characterize the interactions between encapsulated GBS and DCs, with particular emphasis on the receptors involved in DC recognition of encapsulated GBS.
  • Characterize the interactions of encapsulated GBS with Natural Killer (NK) cells.
  • Evaluate the role of DCs in the generation of GBS CPS-specific immune responses by direct activation of B cells or by multiple cross-talks involving NK and T cells.
  • Streptococcus suis: a toxic shock- and meningitis-induced pathogen:
  • Study in vitro the inflammatory response induced by S. suis through activation of divers host phagocytic and non-phagocytic cells (macrophages, neutrophils, epithelial and endothelial cells) and the receptors involved in these interactions.
  • Establish a mouse model for the in vivo study of S. suis induced systemic and central nervous system disorders. To use congenic inbred mouse strains to dissect the genetic pathways involved in host susceptibility to S. suis infection.
  • Study the interaction of S. suis with DCs and the downstream effect on innate and adaptive immune responses by modulation of T cell responses.
  • Sialic acid: a surface component that decorate bacterial exo-polysaccharides:
  • Dissect the role of sialic acid in the interactions of extracellular bacteria with cells of the immune system. Study the effect of sialic acid on the immunogenicity of glycoconjugate vaccines. 

 

Selected Publications

Savard, C., V. Pinilla, C. Provost, M. Segura, C. A. Gagnon, and Y. Chorfi. In vitro effect of deoxynivalenol (DON) mycotoxin on porcine reproductive and respiratory syndrome virus replication. Food and Chemical Toxicology. [Epub ahead of print], 2014.

Lachance, C., M. Segura, M.C. Dominguez-Punaro, G. Wojewodka, J.B. De Sanctis, D. Radzioch, and M.Gottschalk. Deregulated balance of omega-6 and omega-3 polyunsaturated fatty acids following infection by the zoonotic pathogen Streptococcus suis. Infection and Immunity. In press, 2014.

Wang, Y., C.A. Gagnon, C. Savard, N. Music, M. Srednik, M. Segura, C. Lachance, C. Bellehumeur, and M. Gottschalk. Capsular sialic acid of Streptococcus suis serotype 2 binds to swine influenza virus and enhances bacterial interactions with virus-infected tracheal epithelial cells. Infection and Immunity. 81:4498-508, 2013.

Lemire, P., C. Calzas, and M. Segura. The NOD2 receptor does not play a major role in the pathogenesis of Group B Streptococcus in mice. Microbial Pathogenesis. 65:41-47, 2013.

Lachance, C., M. Segura, P. Pereyra-Gerber, J. Xu, and M. Gottschalk. Toll-like receptor 2-independent host innate immune response against an epidemic strain of Streptococcus suis that causes a toxic shock-like syndrome in humans. PLOS One. 8:e65031, 2013.

Lachance, C., M. Gottschalk, P. Pereyra-Gerber, P. Lemire, J.  Xu, and M. Segura. Exacerbated type II interferon response drives hypervirulence and toxic shock by an emergent epidemic strain of Streptococcus suis. Infection and Immunity. 81:1928-39, 2013.

Calzas, C., G. Goyette-Desjardins, P. Lemire, F. Gagnon, C. Lachance, M.R. Van Calsteren, and M. Segura. Group B Streptococcus and Streptococcus suis capsular polysaccharides induce chemokine production by dendritic cells via TLR2- and MyD88-dependent and -independent pathways. Infection and Immunity, 81:3106-3118, 2013.

Van Calsteren, M.R., F. Gagnon, C. Calzas, G. Goyette-Desjardins, M. Okura, D. Takamatsu, M. Gottschalk, and M. Segura. Structure determination of Streptococcus suis serotype 14 capsular polysaccharide. Biochemistry and Cell Biology. 91:49-58, 2013.

Zheng, H., H. Sun, M.C. Dominguez, X. Bai, S. Ji, M. Segura, and J. Xu. Evaluation of the pathogenesis of meningitis caused by Streptococcus suis sequence type 7 using the infection of BV2 microglial cells. Journal of Medical Microbiology. 62: 360-368, 2013.

Lecours, M.P., M. Segura, N. Fittipaldi, S. Rivest, and M. Gottschalk. Immune receptors involved in Streptococcus suis recognition by dendritic cells. PLoS One 7(9):e44746, 2012.

Publications - Mariela Segura