Advanced

Bacterial antibody hydrolyzing enzymes – as bacterial virulence factors and biotechnological tools

Bratanis, Eleni LU (2019) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2019(100).
Abstract (Swedish)
Antibodies are an essential part of the human immune system, and antibody mediated immunity has been an area of interest for many researchers for almost a century. An accumulation of knowledge regarding antibody structure, glycosylation and receptor interactions has contributed to the current understanding of antibody mediated immunity. It has more recently become evident how bacteria and other microorganisms evade host recognition and eradication through specific antibody degradation or modification. The importance of antibody glycosylation and how glycan modification can fine-tune the elicited immune response has also contributed to the development of antibody-based drugs with improved clinical efficacy. In turn these insights have paved... (More)
Antibodies are an essential part of the human immune system, and antibody mediated immunity has been an area of interest for many researchers for almost a century. An accumulation of knowledge regarding antibody structure, glycosylation and receptor interactions has contributed to the current understanding of antibody mediated immunity. It has more recently become evident how bacteria and other microorganisms evade host recognition and eradication through specific antibody degradation or modification. The importance of antibody glycosylation and how glycan modification can fine-tune the elicited immune response has also contributed to the development of antibody-based drugs with improved clinical efficacy. In turn these insights have paved the way and created a need for the development of biotechnological methods and tools to specifically engineer antibodies with defined properties, for analysis to ensure quality and safety, and for improved antibody purification.
This thesis highlights the importance of glycosylation for antibody function and presents different aspects and applications of antibody modifications by bacteria. We show, for the first time, activity of the IgG-specific Streptococcal endoglycosidase EndoS during Streptococcus pyogenes infection, clearly demonstrating that EndoS contributes to S. pyogenes pathogenesis and bacterial survival in the context of adaptive immunity. Further this thesis presents the use of bacterial enzymes as antibody modifying tools and their potential as binding reagents for selective antibody purification. The identification and characterization of two novel proteases, BspK and BspE exhibiting unique IgG and IgA cleavage profiles respectively, from Bdellovibrio bacteriovorus highlights the potential of using Bdellovibrio as a source for the identification of novel enzymes with biotechnological applications. Finally, I present the development of a novel method for selective antibody purification, using the inactive variants of the bacterial enzymes EndoS and EndoS2, ensuring the purification of native, correctly folded and modified antibodies. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • PhD King, Samantha J., The Research Institute at Nationwide Children's Hospital. Columbus, Ohio, USA
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Immunoglobulins, Immunomodulation, Antibody mediated immunity, Glycosylation, Bacterial virulence, Bacterial enzymes, Biotechnology, streptococcus pyogenes, Bdellovibrio bacteriovorus
in
Lund University, Faculty of Medicine Doctoral Dissertation Series
volume
2019
issue
100
pages
87 pages
publisher
Lund University: Faculty of Medicine
defense location
Belfragesalen, BMC D15, Klinikgatan 32 i Lund
defense date
2019-10-25 09:00:00
ISSN
1652-8220
ISBN
978-91-7619-829-2
language
English
LU publication?
yes
id
cd90f38e-1ec9-4ee4-b033-17edd396626d
date added to LUP
2019-10-02 14:39:45
date last changed
2019-11-19 13:49:52
@phdthesis{cd90f38e-1ec9-4ee4-b033-17edd396626d,
  abstract     = {Antibodies are an essential part of the human immune system, and antibody mediated immunity has been an area of interest for many researchers for almost a century. An accumulation of knowledge regarding antibody structure, glycosylation and receptor interactions has contributed to the current understanding of antibody mediated immunity. It has more recently become evident how bacteria and other microorganisms evade host recognition and eradication through specific antibody degradation or modification. The importance of antibody glycosylation and how glycan modification can fine-tune the elicited immune response has also contributed to the development of antibody-based drugs with improved clinical efficacy. In turn these insights have paved the way and created a need for the development of biotechnological methods and tools to specifically engineer antibodies with defined properties, for analysis to ensure quality and safety, and for improved antibody purification.<br/>This thesis highlights the importance of glycosylation for antibody function and presents different aspects and applications of antibody modifications by bacteria. We show, for the first time, activity of the IgG-specific Streptococcal endoglycosidase EndoS during Streptococcus pyogenes infection, clearly demonstrating that EndoS contributes to S. pyogenes pathogenesis and bacterial survival in the context of adaptive immunity. Further this thesis presents the use of bacterial enzymes as antibody modifying tools and their potential as binding reagents for selective antibody purification. The identification and characterization of two novel proteases, BspK and BspE exhibiting unique IgG and IgA cleavage profiles respectively, from Bdellovibrio bacteriovorus highlights the potential of using Bdellovibrio as a source for the identification of novel enzymes with biotechnological applications. Finally, I present the development of a novel method for selective antibody purification, using the inactive variants of the bacterial enzymes EndoS and EndoS2, ensuring the purification of native, correctly folded and modified antibodies.},
  author       = {Bratanis, Eleni},
  isbn         = {978-91-7619-829-2},
  issn         = {1652-8220},
  language     = {eng},
  number       = {100},
  publisher    = {Lund University: Faculty of Medicine},
  school       = {Lund University},
  series       = {Lund University, Faculty of Medicine Doctoral Dissertation Series},
  title        = {Bacterial antibody hydrolyzing enzymes – as bacterial virulence factors and biotechnological tools},
  url          = {https://lup.lub.lu.se/search/ws/files/70264955/Eleni_e_spik_ex.pdf},
  volume       = {2019},
  year         = {2019},
}