title: Comparative immunogenicity and structural analysis of epitopes of different bacterial L-asparaginases.
abstract: BACKGROUND
  E.coli type II L-asparaginase is widely used for treatment of acute lymphoblastic leukemia. However, serious side effects such as allergic or hypersensitivity reactions are common for L-asparaginase treatment. Methods for minimizing immune response on L-asparaginase treatment in human include bioengeneering of less immunogenic version of the enzyme or utilizing the homologous enzymes of different origin. To rationalize these approaches we compared immunogenicity of L-asparaginases from five bacterial organisms and performed sequence-structure analysis of the presumable epitope regions.
  
  
  METHODS
  IgG and IgM immune response in C57B16 mice after immunization with Wollinella succinogenes type II (WsA), Yersinia pseudotuberculosis type II (YpA), Erwinia carotovora type II (EwA), and Rhodospirillum rubrum type I (RrA) and Escherichia coli type II (EcA) L-asparaginases was evaluated using standard ELISA method. The comparative bioinformatics analysis of structure and sequence of the bacterial L-asparaginases presumable epitope regions was performed.
  
  
  RESULTS
  We showed different immunogenic properties of five studied L-asparaginases and confirmed the possibility of replacement of EcA with L-asparaginase from different origin as a second-line treatment. Studied L-asparaginases might be placed in the following order based on the immunogenicity level: YpA > RrA, WsA ≥ EwA > EcA. Most significant cross-immunogenicity was shown between EcA and YpA. We propose that a long N-terminus of YpA enzyme enriched with charged aminoacids and tryptophan could be a reason of higher immunogenicity of YpA in comparison with other considered enzymes. Although the recognized structural and sequence differences in putative epitope regions among five considered L-asparaginases does not fully explain experimental observation of the immunogenicity of the enzymes, the performed analysis set the foundation for further research in this direction.
  
  
  CONCLUSIONS
  The performed studies showed different immunogenic properties of L-asparaginases and confirmed the possibility of replacement of EcA with L-asparaginase from different origin. The preferable enzymes for the second line treatment are WsA, RrA, or EwA.
authors: V.N. Orekhovich Institute of Biomedical Chemistry, Moscow, Russia. vadimpokrovsky@gmail.com.|N.N. Blokhin Cancer Research Center, Moscow, Russia. vadimpokrovsky@gmail.com.
authors: Vadim S
authors: VS
authors: Pokrovsky
authors: Research and Training Center on Bioinformatics, A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Science, Moscow, Russia. mkazanov@gmail.com.
authors: Marat D
authors: MD
authors: Kazanov
authors: I.I. Mechnikov Research Institute of Vaccine and Sera, Moscow, Russia. dyakov.ilya@gmail.com.
authors: Ilya N
authors: IN
authors: Dyakov
authors: V.N. Orekhovich Institute of Biomedical Chemistry, Moscow, Russia. ivan1190@yandex.ru.
authors: Marina V
authors: MV
authors: Pokrovskaya
authors: V.N. Orekhovich Institute of Biomedical Chemistry, Moscow, Russia. v-aleksandrov@yandex.ru.
authors: Svetlana S
authors: SS
authors: Aleksandrova
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D001215:Asparaginase / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology*; D045744:Cell Line, Tumor; D004342:Drug Hypersensitivity / Q000235:genetics / Q000276:immunology*; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005818:Genetic Engineering; D006801:Humans; D051379:Mice; D016973:Pectobacterium carotovorum / Q000201:enzymology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000276:immunology / Q000473:pathology; D012247:Rhodospirillum rubrum / Q000201:enzymology; D015007:Yersinia / Q000201:enzymology
chemical_list: D000939:Epitopes; D001215:Asparaginase