Human articular chondrocytes suppress in vitro proliferation of anti-CD3 activated peripheral blood mononuclear cells.
OBJECTIVE
To investigate whether mature human articular chondrocytes (AC) exhibit an antiproliferative effect on activated peripheral blood mononuclear cells (PBMC) and to compare this effect with other cells of mesenchymal origin.


METHODS
AC from healthy cadaveric cartilage were grown for different passages, in the absence (control) or presence of factors enhancing cell de-differentiation (transforming growth factor (TGF)beta1, fibroblast growth factor (FGF)-2, and platelet derived growth factor (PDGF)bb-TFP medium). Cell ability to suppress PBMC proliferation driven by anti-CD3 antibody was measured by tritiated thymidine uptake following incubation for 48 h at different PBMC:AC ratios and expressed as percent of residual proliferation (RP). AC antiproliferative effect was compared to that of control dermal fibroblasts (DF) and bone marrow stromal cells (BMSC).


RESULTS
AC exhibited a cell number-dependent antiproliferative effect. The strongest effect (up to 2% RP) was measured using the least expanded AC cultures. The use of TFP medium for AC expansion resulted in a significantly lower antiproliferative effect, in the range of that induced by BMSC (up to 18% RP). Also DF induced a marked antiproliferative effect (up to 11% RP).


CONCLUSIONS
We report for the first time that human AC have a marked antiproliferative effect on anti-CD3 stimulated PBMC, which is reduced upon culture in medium-inducing extensive cell de-differentiation. These results reflect the immunosuppressive properties observed for other different mesenchymal cell types and raise the question of a potential common physiological role in local tissue protection.
Bocelli-Tyndall
Chiara
C
Department of Rheumatology, University of Basel, Felix Plattel Spital, Burgfelderstrasse 101, 4012 Basel, Switzerland. chiara.tyndall@fps-basel.ch
Barbero
Andrea
A
Candrian
Christian
C
Ceredig
Rhodri
R
Tyndall
Alan
A
Martin
Ivan
I
D000328:Adult; D000906:Antibodies / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology; D017252:CD3 Complex / Q000378:metabolism*; D002358:Cartilage, Articular / Q000166:cytology*; D049109:Cell Proliferation; D048430:Cell Shape; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D017154:Stromal Cells / Q000166:cytology / Q000502:physiology
D000906:Antibodies; D017252:CD3 Complex