Breaking T cell tolerance against self type II collagen in HLA–DR4–transgenic mice and development of autoimmune arthritis

Abstract

epitope is clearly immunodominant in both tolerized and nontolerized DR4 mice.

A Molecular Analysis of the Shared Epitope Hypothesis: Binding of Arthritogenic Peptides to DRB1*04 Alleles

“…Citrullinated peptides and their native counterparts were chosen based on studies that demonstrated ACPA presence and its ability to elicit T cell responses in HLA-DR shared epitope-positive patients with RA. These were citrullinated vimentin 66-78 (SAVRLRSSVPGVR) (18,21,22), citrullinated aggrecan 89-103 (ATEGRVRVNSAYQDK), citrullinated CILP 297-311 (ATIKAEFVRAETPYM), citrullinated a-enolase [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] (IFDSRGNPTVEVDLF) (20), and unmodified collagen 258-272 (PGIAGFKGEQGPKGE) (23,24), where the underlined arginine indicates the native amino acid that was replaced with citrulline. As a reference control for HLA class II binding, we also tested hemagglutinin A (HA) 306-318 (PKYVKQNTLKLAT).…”

“…We measured binding of native and citrullinated forms of vimentin [66][67][68][69][70][71][72][73][74][75][76][77][78] and a-enolase [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and noncitrullinated type II collagen [258][259][260][261][262][263][264][265][266][267][268][269][270][271][272] to 88 class II alleles on Luminex beads (which includes alleles of many varying degrees of susceptibility and resistance). We expressed DRB1*04:01, *04:02, and *08:01 in T2 cells and mutated DRB1*04:01 at positions 67, 70, 71, 74, and 86 to corresponding residues in DRB1*04:02, *04:03, *04:04, *04:05, and *08:01.…”

“…The most susceptible allele, DRB1*04:01, preferentially bound citrullinated vimentin [66][67][68][69][70][71][72][73][74][75][76][77][78] and citrullinated a-enolase [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] over the native forms. DRB1*04:02 exhibited no preference for citrullinated peptides, and *08:01 preferred native peptides.…”

“…This observation was confirmed by James et al (20), suggesting that the critical amino acids in susceptibility alleles might initiate RA by preferential binding of citrullinated peptides over their native forms. To test this hypothesis over a broad spectrum of HLA alleles, we measured the binding of native and citrullinated forms of vimentin [66][67][68][69][70][71][72][73][74][75][76][77][78] and a-enolase [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] as well as the immunodominant peptide type II collagen [258][259][260][261][262][263][264][265][266][267][268][269][270][271][272] to 88 different HLA-DRB1, DPB1, and DQB1 protein alleles. We then performed site-directed mutagenesis of DRB1*04:01 residues at positions 67, 70, 71, 74, and 86 to the corresponding residues in *04:02, *04:03, *04:04, *04:05, and *08:01 to determine the potential role of each position in the binding of these arthritogenic peptides.…”

Human α‐enolase is immunogenic, but not arthritogenic, in HLA–DR4–transgenic mice: Comment on the article by Kinloch et al

“…The experiment in B10.DR4 Ncf1*/* mice was reproduced using an altered immunization protocol: 100 g protein emulsified in CFA (primary immunization, day 0) and 100 g protein in Freund's incomplete adjuvant (IFA; Difco) (boost, day 21), both injected intradermally at the base of the tail. We further tested the same immunization protocol in HLA-DR4-transgenic mice on a C3H background (C3H.DR4, which are more susceptible to CIA than B10.DR4 mice) (6), and in HLA-DR1-transgenic mice (7) on the B10 background (B10.DR1). HLA-DR1 alleles show association with CEP-1 antibodies in RA, although the association is weaker than that observed with HLA-DR4 alleles (1).…”