Effect of cyclosporine, dexamethasone, and human CTLA4-Ig on production of cytokines in lymphocytes of clinically normal cats and cats undergoing renal transplantation

Objective-To evaluate effects of cyclosporine, dexamethasone, and the immunosuppressive agent human CTLA4-Ig on cytokine production by feline lymphocytes in vitro and to assess patterns of cytokine production for 5 immunosuppressed renal transplant recipient cats. Animals-21 clinically normal cats and 5 immunosupressed renal transplant recipient cats. Procedures-Peripheral blood mononuclear cells were isolated from clinically normal cats and stimulated with concanavalin A (Con A; 10 10 mu g/mL) alone or Con A with cyclosporine (0.05 mu g/mL), dexamethasone (1 X 10(-7)M), a combination of cyclosporine-dexamethasone, or human CTLA4-Ig (10 g/mL). Cells from transplant recipients were stimulated with Con A alone. An ELISA was performed to measure production of interferon (IFN)-gamma, granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (L)-2, IL-4, and IL-10. Proliferation of CD4+ and CD8+T cells from immunosuppressed cats were also evaluated. Pairwise comparisons were performed via a Wilcoxon signed rank test or Wilcoxon rank sum test. Results-Cyclosporine, dexamethasone, cyclosporine-dexamethasone combination, and CTLA4-Ig caused a significant decrease in 11,2, IFN-gamma, and GM-CSF production. Cyclosporine and cyclosporine-dexamethasone, but not human CTLA4-Ig, caused a significant decrease in MO production. High basal concentrations of IL-2 and IL-10 were identified in transplant recipients, and IL-10 was significantly increased in stimulated cultures. In immunosuppressed cats, there was a decrease in frequency of responders and proliferative capacity of CD4+ and CD8+ T cells. Conclusions and Clinical Relevance-CTLA4-Ig successfully inhibited proinflammatory cytokines while sparing cytokines critical for allograft tolerance. These data may be useful for developing better strategies to prevent rejection while sparing other immune functions. (Am J Vet Res 2011;72:541-549)