The pyrimidin analogue cyclopentenyl cytosine induces alloantigen-specific non-responsiveness of human T lymphocytes.
Cyclopentenyl cytosine (CPEC) has been shown to induce apoptosis in human T lymphoblastic cell lines and T cells from leukaemia patients. In this study we have addressed the question of whether CPEC is able to decrease proliferation and effector functions of human alloresponsive T lymphocytes and induce T cell anergy. The proliferative capacity of human peripheral blood mononuclear cells in response to allogeneic stimulation was measured by 5,6-carboxy-succinimidyl-diacetate-fluorescein-ester staining. Flow cytometric analysis was performed using surface CD4, CD8, CD25, CD103 and intracellular perforin, granzyme A, granzyme B, caspase-3 and forkhead box P3 (FoxP3) markers. The in vivo immunosuppressive capacity was tested in a murine skin graft model. Addition of CPEC at a concentration of 20 nM strongly decreased the expansion and cytotoxicity of alloreactive T cells. Specific restimulation in the absence of CPEC showed that the cells became anergic. The drug induced caspase-dependent apoptosis of alloreactive T lymphocytes. Finally, CPEC increased the percentage of CD25(high) FoxP3+ CD4+ and CD103+ CD8+ T cells, and potentiated the effect of rapamycin in increasing the numbers of alloreactive regulatory T cells. Treatment with CPEC of CBA/CA mice transplanted with B10/Br skin grafts significantly prolonged graft survival. We conclude that CPEC inhibits proliferation and cytotoxicity of human alloreactive T cells and induces alloantigen non-responsiveness in vitro.
Department of Experimental Immunology, Division of Nephrology, Academic Medical Centre, Amsterdam, The Netherlands.
N
N
Nikolaeva
F J
FJ
Bemelman
S-L
SL
Yong
A
A
Verschuur
R A W
RA
van Lier
I J M
IJ
ten Berge
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017635:Clonal Anergy / Q000187:drug effects* / Q000276:immunology; D003562:Cytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D004306:Dose-Response Relationship, Immunologic; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007519:Isoantigens / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D051379:Mice; D008815:Mice, Inbred Strains; D016038:Skin Transplantation; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology
D004791:Enzyme Inhibitors; D007166:Immunosuppressive Agents; D007519:Isoantigens; D003562:Cytidine; C045911:cyclopentenyl cytosine