Comparison of the Effect of Standard and Novel Immunosuppressive Drugs on CMV-Specific T-Cell Cytokine Profiling

Background. Data on how different immunosuppressive drugs affect cytomegalovirus (CMV)-specific T-cell responses may help guide more rational modification of immunosuppression in patients with CMV replication. We assessed the in vitro effects of individual standard and novel immunosuppressive drugs on a broad range of CMV-specific T-cell responses. Methods. Peripheral blood mononuclear cells from healthy CMV-seropositive donors were preincubated with serial dilutions of tacrolimus, mycophenolate (MPA), sirolimus, tofacitinib, and belatacept. CMV-pp65 or CMV-pp72 peptide pools were used for stimulation. CMV-specific cytokine (Th1 and Th2) and chemokine responses were determined (a total of 5400 measurements). P<0.01 was set as significant. Results. After CMV stimulation, dose-dependent suppression of Th1, Th2, and chemokines was seen, but significant differences between drugs were present. For example, tacrolimus was more potent in inhibiting CMV-specific Th1 cytokines versus Th2, whereas MPA preferentially inhibited Th2 cytokines. In a comparison of the relative potency of each drug at different dosing ranges, tacrolimus had the strongest Th1 inhibitory effect (median inhibition of interferon-gamma at 97.5%; P=0.004-0.008) followed by sirolimus (median inhibition at 82.4%). The remaining agents (MPA, belatacept, and tofacitinib) had less apparent dose-dependent effects on interferon-gamma (belatacept median inhibition at 21.5%; P=0.004 vs. tacrolimus). Conclusion. Immunosuppression-specific and dose-dependent reductions in CMV-specific cytokine release were observed with significant differences in Th1 versus Th2 profiles and in relative potency of the drugs.