T cell reactivity against the SmD1(83-119) C terminal peptide in patients with systemic lupus erythematosus.
BACKGROUND
The SmD1(83-119) peptide is a major target of the B cell response in patients with systemic lupus erythematosus (SLE).


OBJECTIVE
To investigate the T cell response directed against this peptide, its disease specificity, and possible impact on SLE pathogenesis.


METHODS
Peripheral blood mononuclear cells derived from 28 patients with SLE and 29 healthy and disease controls were stimulated by the SmD1(83-119) and the recombinant (r)SmD1 protein, and [3H]thymidine incorporation was measured. Patients with SLE were simultaneously tested for autoantibodies, disease activity, clinical symptoms, and medical treatments.


RESULTS
T cell reactivity against the SmD1(83-119) peptide was detected in 11/28 (39%) patients with SLE and against the rSmD1 protein in 10/28 (36%) patients. In contrast, only 2/29 (7%) controls exhibited SmD1 reactivity. An analysis of proliferation kinetics showed that SmD1 reactive T cells are activated in vivo, as additionally confirmed by cytometric analysis. Addition of mammalian dsDNA to rSmD1 enhanced the rSmD1-specific T cell response. SmD1(83-119)-specific T cell reactivity was significantly more common in patients with cardiac and pulmonary symptoms. No correlation between T and B cell responses and disease activity was seen.


CONCLUSIONS
SmD1(83-119) is a major T cell epitope of SmD1, commonly recognised by T cells from patients with SLE and much less commonly found by healthy or disease controls. This strong T cell reactivity as well as the high frequency and specificity of anti-SmD1(83-119) antibodies in SLE suggest a possible role in SLE pathogenesis, at least in a subset of patients.
Riemekasten
G
G
Department of Rheumatology and Clinical Immunology, Charité University Hospital, Schumannstr 20/21, D-10117 Berlin, Germany. gabriela.riemekasten@charite.de
Weiss
C
C
Schneider
S
S
Thiel
A
A
Bruns
A
A
Schumann
F
F
Bläss
S
S
Burmester
G-R
GR
Hiepe
F
F
D000328:Adult; D001172:Arthritis, Rheumatoid / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens; D001402:B-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D002455:Cell Division; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008213:Lymphocyte Activation; D008875:Middle Aged; D017411:Ribonucleoproteins, Small Nuclear / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D055517:snRNP Core Proteins
D001323:Autoantibodies; D001324:Autoantigens; D017411:Ribonucleoproteins, Small Nuclear; C526409:SNRPD1 protein, human; D055517:snRNP Core Proteins