The effect of immunosuppressive drugs on the generation of T follicular helper (Tfh) cells, specialized in supporting B-cell differentiation, is largely unknown. We examined whether the calcineurin inhibitor tacrolimus (TAC) and the mammalian target of rapamycin (mtor) inhibitor sirolimus (SRL) inhibit Tfh cell differentiation, and affect subsequent B-cell functions. Isolated naive T cells were polarized into Tfh-like cells in the presence of TAC or SRL. To demonstrate their functionality, we co-cultured these cells with isolated B cells in the presence of alloantigen and studied the activation and differentiation of these B cells. Tfh-like cells were defined as CD4+CXCR5+ T cells, expressing immunoinhibitory programmed death protein 1 (pd1) and inducible T-cell costimulator (icos). We found that TAC and SRL significantly inhibited Tfh-like cell differentiation. Therapeutic concentrations of TAC and SRL reduced the percentage of pd1+ and icos+ Tfh cells compared to controls. In addition, T cells grown in the presence of TAC or SRL expressed less IL-21 and provided less B-cell help. TAC and SRL both inhibited Tfh-dependent alloantigen-activated B-cell proliferation and differentiation into plasma cells and transitional B cells. In conclusion, TAC and SRL inhibited the differentiation of naive T cells into functional Tfh-like cells, a finding that can be extrapolated to immunosuppressive regimens in transplant patients.

Additional Metadata
Persistent URL dx.doi.org/10.1016/j.transproceed.2019.08.039, hdl.handle.net/1765/121886
Journal Transplantation Proceedings
Citation
Kraaijeveld, R, Li, Y. (Yi), Yan, L. (Lin), de Leur, K, Dieterich, M, Peeters, A.M.A. (Annemiek M.A.), … Baan, C.C. (2019). Inhibition of T Helper Cell Differentiation by Tacrolimus or Sirolimus Results in Reduced B-Cell Activation: Effects on T Follicular Helper Cells. Transplantation Proceedings. doi:10.1016/j.transproceed.2019.08.039