Identification of an altered peptide ligand based on the endogenously presented, rheumatoid arthritis-associated, human cartilage glycoprotein-39(263-275) epitope: an MHC anchor variant peptide for immune modulation.
We sought to identify an altered peptide ligand (APL) based on the endogenously expressed synovial auto-epitope of human cartilage glycoprotein-39 (HC gp-39) for modulation of cognate, HLA-DR4-restricted T cells. For this purpose we employed a panel of well-characterized T cell hybridomas generated from HC gp-39-immunized HLA-DR4 transgenic mice. The hybridomas all respond to the HC gp-39(263-275) epitope when bound to HLA-DR4(B1*0401) but differ in their fine specificities. First, the major histocompatibility complex (MHC) and T-cell receptor (TCR) contact residues were identified by analysis of single site substituted analogue peptides for HLA-DR4 binding and cognate T cell recognition using both T hybridomas and polyclonal T cells from peptide-immunized HLA-DR4 transgenic mice. Analysis of single site substituted APL by cognate T cells led to identification of Phe265 as the dominant MHC anchor. The amino acids Ala268, Ser269, Glu271 and Thr272 constituted the major TCR contact residues, as substitution at these positions did not affect HLA-DR4(B1*0401) binding but abrogated T cell responses. A structural model for visualisation of TCR recognition was derived. Second, a set of non-classical APLs, modified at the MHC key anchor position but with unaltered TCR contacts, was developed. When these APLs were analysed, a partial TCR agonist was identified and found to modulate the HC gp-39(263-275)-specific, pro-inflammatory response in HLA-DR4 transgenic mice. We identified a non-classical APL by modification of the p1 MHC anchor in a synovial auto-epitope. This APL may qualify for rheumatoid arthritis immunotherapy.
Boots
Annemieke M H
AM
NV Organon, Research Laboratories, Oss, The Netherlands. mieke.boots@organon.com
Hubers
Henk
H
Kouwijzer
Milou
M
den Hoed-van Zandbrink
Leontien
L
Westrek-Esselink
Bernice M
BM
van Doorn
Cindy
C
Stenger
Rachel
R
Bos
Ebo S
ES
van Lierop
Marie-jose C
MJ
Verheijden
Gijs F
GF
Timmers
Cornelis M
CM
van Staveren
Catharina J
CJ
D054392:Adipokines; D000818:Animals; D016525:Antigenic Modulation / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism; D000071451:Chitinase-3-Like Protein 1; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism; D015804:HLA-DR4 Antigen / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D006825:Hybridomas; D016056:Immunodominant Epitopes / Q000276:immunology / Q000378:metabolism; D037102:Lectins; D051379:Mice; D008822:Mice, Transgenic; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D015804:HLA-DR4 Antigen; D016056:Immunodominant Epitopes; D037102:Lectins