title: Proteoglycan-induced arthritis and recombinant human proteoglycan aggrecan G1 domain-induced arthritis in BALB/c mice resembling two subtypes of rheumatoid arthritis.
abstract: OBJECTIVE
  To develop a simplified and relatively inexpensive version of cartilage proteoglycan-induced arthritis (PGIA), an autoimmunity model of rheumatoid arthritis (RA), and to evaluate the extent to which this new model replicates the disease parameters of PGIA and RA.
  
  
  METHODS
  Recombinant human G1 domain of human cartilage PG containing "arthritogenic" T cell epitopes was generated in a mammalian expression system and used for immunization of BALB/c mice. The development and progression of arthritis in recombinant human PG G1-immunized mice (designated recombinant human PG G1-induced arthritis [GIA]) was monitored, and disease parameters were compared with those in the parent PGIA model.
  
  
  RESULTS
  GIA strongly resembled PGIA, although the clinical symptoms and immune responses in mice with GIA were more uniform than in those with PGIA. Mice with GIA showed evidence of stronger Th1 and Th17 polarization than those with PGIA, and anti-mouse PG autoantibodies were produced in different isotype ratios in the 2 models. Rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies were detected in both models; however, serum levels of IgG-RF and anti-CCP antibodies were different in GIA and PGIA, and both parameters correlated better with disease severity in GIA than in PGIA.
  
  
  CONCLUSIONS
  GIA is a novel model of seropositive RA that exhibits all of the characteristics of PGIA. Although the clinical phenotypes are similar, GIA and PGIA are characterized by different autoantibody profiles, and the 2 models may represent 2 subtypes of seropositive RA, in which more than 1 type of autoantibody can be used to monitor disease severity and response to treatment.
authors.affiliation: Rush University Medical Center, Chicago, Illinois. Tibor_Glant@rsh.net
authors.forename: Tibor T
authors.initials: TT
authors.lastname: Glant
authors.forename: Marianna
authors.initials: M
authors.lastname: Radacs
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Nagyeri
authors.forename: Katalin
authors.initials: K
authors.lastname: Olasz
authors.forename: Anna
authors.initials: A
authors.lastname: Laszlo
authors.forename: Ferenc
authors.initials: F
authors.lastname: Boldizsar
authors.forename: Akos
authors.initials: A
authors.lastname: Hegyi
authors.forename: Alison
authors.initials: A
authors.lastname: Finnegan
authors.forename: Katalin
authors.initials: K
authors.lastname: Mikecz
mesh_terms: D053674:Aggrecans / Q000276:immunology / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D001169:Arthritis, Experimental / Q000097:blood / Q000139:chemically induced / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000139:chemically induced / Q000276:immunology*; D002358:Cartilage, Articular / Q000276:immunology*; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007114:Immunization; D007378:Interleukins / Q000097:blood / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011509:Proteoglycans / Q000276:immunology / Q000494:pharmacology*; D012217:Rheumatoid Factor / Q000097:blood; D013601:T-Lymphocytes
chemical_list: D053674:Aggrecans; D007378:Interleukins; D011509:Proteoglycans; D012217:Rheumatoid Factor