Bone marrow-derived mesenchymal stem cells inhibit T follicular helper cell in lupus-prone mice

Background The objective of this paper is to analyze the role of bone marrow-derived mesenchymal stem cells (BM-MSCs) on the differentiation of T follicular helper (Tfh) cells in lupus-prone mice. Methods Bone marrow cells were isolated from C57BL/6 (B6) mice and cultured in vitro, and surface markers were identified by flow cytometry. Naïve CD4⁺ T cells, splenocytes and Tfh cells were isolated from B6 mice spleens and co-cultured with BM-MSCs. The proliferation and the differentiation of CD4⁺ T cells and Tfh cells were analyzed by flow cytometry. Lupus-prone MRL/Mp-lpr/lpr (MRL/lpr) mice were treated via intravenous injection with expanded BM-MSCs, the differentiation of Tfh cells was detected, and the relief of lupus nephritis was analyzed. Results MSCs could be successfully induced from bone marrow cells, and cultured BM-MSCs could inhibit T cell proliferation dose-dependently. BM-MSCs could prevent Tfh cell development from naïve CD4⁺ T cells and splenocytes. BM-MSCs could inhibit IL-21 gene expression and cytokine production and inhibit isolated Tfh cells and STAT3 phosphorylation. In vivo study proved that BM-MSCs intravenous injection could effectively inhibit Tfh cell expansion and IL-21 production, alleviate lupus nephritis, and prolong the survival rate of lupus-prone mice. Conclusions BM-MSCs could effectively inhibit the differentiation of Tfh cells both in vitro and in vivo. BM-MSC treatment could relieve lupus nephritis, which indicates that BM-MSCs might be a promising therapeutic method for the treatment of SLE.