Regulatory Cell Populations in Relapsing-Remitting Multiple Sclerosis (RRMS) Patients: Effect of Disease Activity and Treatment Regimens.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) of autoimmune etiology that results from an imbalance between CNS-specific T effector cells and peripheral suppressive mechanisms mediated by regulatory cells (RC). In this research, we collected blood samples from 83 relapsing remitting MS (RRMS) patients and 45 healthy persons (HC), to assess the sizes of their RC populations, including CD4⁺CD25(high)Foxp3⁺ (nTregs), CD3⁺CD4⁺HLA(-)G⁺, CD3⁺CD8⁺CD28(-), CD3⁺CD56⁺, and CD56(bright) cells, and how RC are affected by disease activity (acute phase or remission) and types of treatment (methylprednisolone, interferon, or natalizumab). In addition, we isolated peripheral blood mononuclear cells (PBMC) and cultured them with peptides mapping to myelin antigens, to determine RC responsiveness to autoantigens. The results showed decreased levels of nTregs in patients in the acute phase ± methylprednisolone and in remission + natalizumab, but HC levels in patients in remission or receiving interferon. Patients + interferon had the highest levels of CD3⁺CD4⁺HLA(-)G⁺ and CD3⁺CD8⁺CD28(-) RC, and patients in the acute phase + methylprednisolone the lowest. Patients in remission had the highest levels of CD3⁺CD56⁺, and patients in remission + natalizumab the highest levels of CD56(bright) cells. Only nTregs responded to autoantigens in culture, regardless of disease activity or treatment. The highest suppressive activity was exhibited by nTregs from patients in remission. In conclusion, in RRMS disease activity and type of treatment affect different RC populations. nTregs respond to myelin antigens, indicating that it is possible to restore immunological tolerance through nTreg induction.

Different immunosuppressive combinations on T-cell regulation in renal transplant recipients.

BACKGROUND/AIMS: Recent studies indicate that regulatory T-cells (Tregs) promote transplant tolerance. We studied Treg levels in 39 stable renal transplant recipients to determine the sizes of the Treg populations and the effects of treatment regimens thereof. METHODS: All patients (19 with good graft function and 20 with chronic allograft nephropathy) received induction therapy (basiliximab) and were on triple immunosuppressive regimens with calcineurin inhibitors (cyclosporine or tacrolimus), mycophenolate mofetil (MMF) or everolimus and steroids. Twenty healthy subjects served as controls. Whole blood samples were stained with anti-CD4, CD25, CD127, and FoxP3 antibodies and analyzed by flow cytometry to determine CD4+CD25(high)FoxP3+/- and CD4+ CD25(high)CD127(-/low) Treg levels. RESULTS: All patients had significantly reduced CD4+CD25(high)FoxP3+/- but no CD4+ CD25(high)CD127(-/low) Treg levels compared to controls. Renal allograft function did not correlate with Treg levels. Statistically significant correlations between CD4+CD25(high)Foxp3+ Tregs and tacrolimus levels and CD4+CD25(high)Foxp3- Tregs and HLA-DR mismatching were detected. Patients receiving MMF had significantly higher CD4+CD25(high)Foxp3+ Tregs compared to patients on everolimus who were also receiving lower doses of calcineurin inhibitors. CONCLUSION: Overall, immunosuppression lowers CD4+CD25(high)FoxP3+/- Treg levels significantly in the periphery in renal transplant recipients. In addition, different immunosuppressive regimens have different impacts on CD4+CD25(high)FoxP3+ Tregs, a fact that may influence long-term allograft survival.