The effects of B cell subsets with regulatory activity on the immune response to an allograft have evoked increasing interest. Here, we summarize the function and signaling of regulatory B cells (Bregs) and their potential effects on transplantation. These cells are able to suppress the immune system directly via ligand–receptor interactions and indirectly by secretion of immunosuppressive cytokines, particularly IL‐10. In experimental animal models, the extensively studied IL‐10‐producing B cells have shown unique therapeutic advantages in the transplant field. In addition, adoptive transfer of B cell subsets with regulatory activity may reveal a new approach to prolonging allograft survival. Recent clinical observations on currently available therapies targeting B cells have revealed that Bregs play an important role in immune tolerance and that these cells are expected to become a new target of immunotherapy for transplant‐related diseases.

The aim of the present study was to investigate the value of combined detection of serum carcino-embryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and cyclooxygenase-2 (COX-2) in the diagnosis of colorectal cancer. A total of 50 patients with colorectal cancer were selected as Group A and 50 healthy subjects as the control group. A sample of 2 ml fasting venous blood was drawn from patients in each group, and serum CEA, CA19-9 and COX-2 were detected using electrochemiluminescence analyzer and ELISA. Receiver operating characteristic curve analysis was performed on analyze the sensitivity and specificity of diagnostic methods for colorectal cancer patients at different stages. The expression levels of CEA, CA199 and COX-2 in the cancer patients group were significantly higher than those in the healthy group (P<0.05). The coincidence rates of CEA, CA199, COX-2 and combined detection were 56.0, 64.0, 62.0 and 88.0%, respectively. The coincidence rate of combined detection was significantly higher than that of diagnosis using a single factor (P<0.05). Sensitivity of combined detection of colorectal cancer patients with stage I, II, III and IV were 82.9, 85.3, 86.4 and 88.7%, respectively. The specificities were 65.3, 68.7, 57.8 and 58.6%, respectively. Thus, CEA, CA199 and COX-2 in serum are highly expressed in colorectal cancer patients, and may useful as effective indicators for the early diagnosis of colorectal cancer.

The increase in T helper 17 cell (Th17)-mediated pro-inflammatory response and decrease in regulatory T cell (Treg)-mediated anti-inflammatory effect aggravate renal tubular epithelial cell (RTEC) injury. However, increasing evidence indicated that mesenchymal stem cell (MSC) possessed the ability to control the imbalance between Th17 and Treg. Given that Th17 and Treg are derived from a common CD4+ T cell precursor, we summarize the current knowledge of MSC-mediated inhibition of the mammalian target of rapamycin (mTOR), which is a master regulator of CD4+ T cell polarization. During CD4+ T cell differentiation, mTOR signaling mediates Th17 and Treg differentiation via hypoxia-inducible factor-1α (HIF-1α)-dependent metabolic regulation and signaling pathway, as well as mTOR-mediated phosphorylation of signal transducer and activator of transcription (STAT) 3 and 5. Through interfering with mTOR signaling, MSC restrains CD4+ T cell differentiation into Th17, but in turn promotes Treg generation. Thus, this review indicates that MSC-mediated Th17-to-Treg polarization is expected to act as new immunotherapy for kidney injury.