Professional Education

  • Doctor of Philosophy, Universitetet I Oslo (2014)
  • Master of Science, Bangalore University (2014)
  • Bachelor of Science, Sri Venkateswara University (2001)


All Publications

  • Streptococcus pyogenes evades adaptive immunity through specific IgG glycan hydrolysis JOURNAL OF EXPERIMENTAL MEDICINE Naegeli, A., Bratanis, E., Karlsson, C., Shannon, O., Kalluru, R., Linder, A., Malmstrom, J., Collin, M. 2019; 216 (7): 1615?29


    Streptococcus pyogenes (Group A streptococcus; GAS) is a human pathogen causing diseases from uncomplicated tonsillitis to life-threatening invasive infections. GAS secretes EndoS, an endoglycosidase that specifically cleaves the conserved N-glycan on IgG antibodies. In vitro, removal of this glycan impairs IgG effector functions, but its relevance to GAS infection in vivo is unclear. Using targeted mass spectrometry, we characterized the effects of EndoS on host IgG glycosylation during the course of infections in humans. Substantial IgG glycan hydrolysis occurred at the site of infection and systemically in the severe cases. We demonstrated decreased resistance to phagocytic killing of GAS lacking EndoS in vitro and decreased virulence in a mouse model of invasive infection. This is the first described example of specific bacterial IgG glycan hydrolysis during infection and thereby verifies the hypothesis that EndoS modifies antibodies in vivo. This mechanisms of immune evasion could have implications for treatment of severe GAS infections and for future efforts at vaccine development.

    View details for DOI 10.1084/jem.20190293

    View details for Web of Science ID 000473325900013

    View details for PubMedID 31092533

    View details for PubMedCentralID PMC6605743

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