title: Comparative analysis of collagen type II-specific immune responses during development of collagen-induced arthritis in two B10 mouse strains.
abstract: BACKGROUND
  Immune responses against collagen type II (CII) are crucial for the development of collagen-induced arthritis (CIA). The aim of the present study was to evaluate and compare the CII-directed T cell and antibody specificity at different time points in the course of CIA using two mouse strains on the B10 genetic background - B10.Q, expressing Aq MHC class II molecules, and B10.DR4.Ncf1*/*, expressing human rheumatoid arthritis-associated MHC II DR4 molecules (DRA*0101/DRB*0401).
  
  
  METHODS
  B10.Q and B10.DR4.Ncf1*/* mice were immunized with CII emulsified in adjuvant and development of CIA was assessed. T cells from draining lymph nodes were restimulated in vitro with CII peptides and interferon-gamma (IFN-γ) levels in culture supernatants were evaluated by ELISA. CII-specific antibody levels in serum samples were measured by ELISA.
  
  
  RESULTS
  At four different CIA time points we analyzed T cell specificity to the immunodominant CII epitope 259-273 (CII259-273) and several posttranslationally modified forms of CII259-273 as well as antibody responses to three B cell immunodominant epitopes on CII (C1, U1, J1). Our data show that CII-specific T and B cell responses increase dramatically after disease onset in both strains and are sustained during the disease course. Concerning anti-CII antibody fine specificity, during all investigated stages of CIA the B10.Q mice responded predominantly to the C1 epitope, whereas the B10.DR4.Ncf1*/* mice also recognized the U1 epitope. In the established disease phase, T cell reactivity toward the galactosylated CII259-273 peptide was similar between the DR4- and the Aq-expressing strains whereas the response to the non-modified CII peptide was dramatically enhanced in the DR4 mice compared with the B10.Q. In addition, we show that the difference in the transgenic DR4-restricted T cell specificity to CII259-273 is not dependent on the degree of glycosylation of the collagen used for immunization.
  
  
  CONCLUSIONS
  The present study provides important evaluation of CII-specific immune responses at different phases during CIA development as well as a comparative analysis between two CIA mouse models. We indicate significant differences in CII T cell and antibody specificities between the two strains and highlight a need for improved humanized B10.DR4 mouse model for rheumatoid arthritis.
authors.forename: Tsvetelina
authors.initials: T
authors.lastname: Batsalova
authors.forename: Ingrid
authors.initials: I
authors.lastname: Lindh
authors.forename: Johan
authors.initials: J
authors.lastname: Bäcklund
authors.forename: Balik
authors.initials: B
authors.lastname: Dzhambazov
authors.forename: Rikard
authors.initials: R
authors.lastname: Holmdahl
mesh_terms: D000818:Animals; D000917:Antibody Formation / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology*; D001169:Arthritis, Experimental / Q000276:immunology*; D024043:Collagen Type II / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D008297:Male; D008822:Mice, Transgenic; D013045:Species Specificity; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D013997:Time Factors
chemical_list: D024043:Collagen Type II; D018984:Epitopes, T-Lymphocyte; D007371:Interferon-gamma