ABSTRACT
IL-10-producing CD1d(hi)CD5(+) B cells, also known as B10 cells, have been shown to possess a regulatory function in the inhibition of immune responses, but whether and how B10 cells suppress the development of autoimmune arthritis remain largely unclear. In this study, we detected significantly decreased numbers of IL-10-producing B cells, but increased IL-17-producing CD4(+) T (Th17) cells in both spleen and draining lymph nodes of mice during the acute stage of collagen-induced arthritis (CIA) when compared with adjuvant-treated control mice. On adoptive transfer of in vitro expanded B10 cells, collagen-immunized mice showed a marked delay of arthritis onset with reduced severity of both clinical symptoms and joint damage, accompanied by a substantial reduction in the number of Th17 cells. To determine whether B10 cells directly inhibit the generation of Th17 cells in culture, naive CD4(+) T cells labeled with carboxyfluorescein succinimidyl ester (CFSE) were co-cultured with B10 cells. These B10 cells suppressed Th17 cell differentiation via the reduction of STAT3 phosphorylation and retinoid-related orphan receptor γt (RORγt) expression. Moreover, Th17 cells showed significantly decreased proliferation when co-cultured with B10 cells. Although adoptive transfer of Th17 cells triggered the development of collagen-induced arthritis in IL-17(-/-)DBA/1J mice, co-transfer of B10 cells with Th17 cells profoundly delayed the onset of arthritis. Thus, our findings suggest a novel regulatory role of B10 cells in arthritic progression via the suppression of Th17 cell generation.
Subject(s)
Arthritis, Experimental/prevention & control , B-Lymphocyte Subsets/immunology , Interleukin-10/biosynthesis , Th17 Cells/immunology , Adoptive Transfer/methods , Animals , Arthritis, Experimental/immunology , Arthritis, Experimental/pathology , B-Lymphocyte Subsets/transplantation , Cell Differentiation/immunology , Cells, Cultured , Interleukin-17/biosynthesis , Interleukin-17/deficiency , Lymph Nodes/immunology , Lymphocyte Transfusion/methods , Mice , Mice, Inbred DBA , Mice, Knockout , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , Phosphorylation/immunology , STAT3 Transcription Factor/metabolism , Spleen/immunologyABSTRACT
Previous studies have shown that the anomalous fruit extract of Gleditsia sinensis (GSE) exhibited apoptotic properties in various solid and non-solid tumors in vitro. However, the inhibitory actions of GSE on oncogenic expression and telomerase activity in esophageal squamous cell carcinoma (ESCC) have not been studied before. In the present study, the anti-cancer effects of GSE were demonstrated in three ESCC cell lines (HKESC-1, HKESC-2 and SLMT-1) by MTS and anchorage-independent clongen-icity assays, expression studies on oncogenes at 11q13 (CCND1, INT2, FGF4 and EMS1) and real-time quantitative telomeric repeat amplification protocol assay to show the inhibitory effect of GSE on telomerase in ESCC. The means of MTS50 of GSE for the ESCC cell lines and non-tumor NIH 3T3 cells were 21 and 163 microg/ml respectively. The anchorage-independent clongenicity assay showed that SLMT-1 cells lost their colony-forming potential which was dose-dependent to GSE. Moreover, GSE demonstrated dose-dependent suppression on the expression of INT2, EMS1 and FGF4, and inhibition of telomerase activity in the ESCC cell lines. Our overall results thus provide the first evidence that the anti-cancer effects of GSE on ESCC involve the suppression of oncogenic expression and inhibition of telomerase activity. Our findings also offer a new opportunity for the future development of GSE as a novel anti-cancer agent for ESCC and possibly for other cancers.