title: Investigation of the immunogenicity of different types of aggregates of a murine monoclonal antibody in mice.
abstract: OBJECTIVE
  The potential contribution of protein aggregates to the unwanted immunogenicity of protein pharmaceuticals is a major concern. In the present study a murine monoclonal antibody was utilized to study the immunogenicity of different types of aggregates in mice. Samples containing defined types of aggregates were prepared by processes such as stirring, agitation, exposure to ultraviolet (UV) light and exposure to elevated temperatures.
  
  
  METHODS
  Aggregates were analyzed by size-exclusion chromatography, light obscuration, turbidimetry, infrared (IR) spectroscopy and UV spectroscopy. Samples were separated into fractions based on aggregate size by asymmetrical flow field-flow fractionation or by centrifugation. Samples containing different types and sizes of aggregates were subsequently administered to C57BL/6 J and BALB/c mice, and serum was analyzed for the presence of anti-IgG1, anti-IgG2a, anti-IgG2b and anti-IgG3 antibodies. In addition, the pharmacokinetic profile of the murine antibody was investigated.
  
  
  RESULTS
  In this study, samples containing high numbers of different types of aggregates were administered in order to challenge the in vivo system. The magnitude of immune response depends on the nature of the aggregates. The most immunogenic aggregates were of relatively large and insoluble nature, with perturbed, non-native structures.
  
  
  CONCLUSIONS
  This study shows that not all protein drug aggregates are equally immunogenic.
authors.affiliation: Department of Pharmacy, Pharmaceutical Technology & Biopharmaceutics, Ludwig-Maximilians-University Munich, Butenandtstr. 5, D-81377, Munich, Germany.
authors.forename: Angelika J
authors.initials: AJ
authors.lastname: Freitag
authors.forename: Maliheh
authors.initials: M
authors.lastname: Shomali
authors.forename: Stylianos
authors.initials: S
authors.lastname: Michalakis
authors.forename: Martin
authors.initials: M
authors.lastname: Biel
authors.forename: Michael
authors.initials: M
authors.lastname: Siedler
authors.forename: Zehra
authors.initials: Z
authors.lastname: Kaymakcalan
authors.forename: John F
authors.initials: JF
authors.lastname: Carpenter
authors.forename: Theodore W
authors.initials: TW
authors.lastname: Randolph
authors.forename: Gerhard
authors.initials: G
authors.lastname: Winter
authors.forename: Julia
authors.initials: J
authors.lastname: Engert
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D000917:Antibody Formation / Q000187:drug effects / Q000276:immunology*; D005260:Female; D055261:Immunogenetic Phenomena / Q000187:drug effects / Q000276:immunology*; D007074:Immunoglobulin G / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G