Cytokines elicited by T cell epitopes from a synovial autoantigen: altered peptide ligands can reduce interferon-gamma and interleukin-10 production.
OBJECTIVE
To explore the cytokine responses associated with T cell epitopes from human cartilage glycoprotein 39 (HC gp-39) and the potential for modifying cytokine secretion using altered peptide ligands (APLs).


METHODS
Draining lymph node cells were harvested from HLA-DR*0401 transgenic mice that had been immunized with HC gp-39. Cytokine responses to 5 previously identified HLA-DR*0401-restricted HC gp-39 T cell epitopes were studied in vitro. The anchor and T cell receptor (TCR) contact residues of peptide 322-337 were identified, and this information was used to design alanine-substituted APLs. T cells were primed in vivo with wild-type peptide 322-337, restimulated with wild-type peptide or APLs, and the cytokine profiles were compared.


RESULTS
Restimulation with individual peptides elicited distinct cytokine profiles. HC gp-39 (peptide 322-337) elicited a dominant interferon-gamma (IFNgamma) response. Residues within the core (positions P1-P9) 322-337 peptide sequence were critical for T cell recognition. Surprisingly, the N-terminal flanking region was also important for recognition by 6 of 10 specific T cell hybridomas. Substitutions of charged TCR contact residues in the 322-337 core epitope (E332A and K335A) were associated with a significant reduction in the IFNgamma and interleukin-10 (IL-10) stimulation indices. Restimulation with peptides W325A and V326A was also associated with a trend toward reduced IFNgamma and IL-10 secretion. In contrast, restimulation with peptide D330N elicited cytokine profiles more comparable with those resulting from restimulation with wild-type peptide.


CONCLUSIONS
This study indicates that APLs of a proinflammatory HC gp-39 T cell epitope may be used to alter the cytokine response from a memory T cell population.
Hall
Frances C
FC
Stanford University School of medicine, 299 Campus Drive, Stanford, CA 94305, USA.
Visconti
Kevin C
KC
Ahmad
Regina-Celeste
RC
Parry
Sarah L
SL
Miltenburg
André M M
AM
McConnell
Harden M
HM
Mellins
Elizabeth D
ED
Sønderstrup
Grete
G
D054392:Adipokines; D000818:Animals; D001324:Autoantigens / Q000276:immunology*; D002478:Cells, Cultured; D000071451:Chitinase-3-Like Protein 1; D018984:Epitopes, T-Lymphocyte / Q000276:immunology* / Q000378:metabolism; D006023:Glycoproteins / Q000276:immunology* / Q000494:pharmacology; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology; D006801:Humans; D007114:Immunization; D007156:Immunologic Memory / Q000276:immunology; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000378:metabolism; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000378:metabolism; D037102:Lectins; D008024:Ligands; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology; D013583:Synovial Membrane / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism
D054392:Adipokines; D001324:Autoantigens; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D018984:Epitopes, T-Lymphocyte; D006023:Glycoproteins; D006684:HLA-DR Antigens; D037102:Lectins; D008024:Ligands; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; D016753:Interleukin-10; D007371:Interferon-gamma