Treatment with Allogenic Mesenchymal Stromal Cells in a Murine Model of Systemic Lupus Erythematosus.

OBJECTIVE: Pre-clinical and uncontrolled studies in patients with systemic lupus erythematosus (SLE) showed that mesenchymal stromal cells (MSCs) have a potential therapeutic role in refractory cases. The optimal therapeutic strategy in these patients remain to be elucidated. Our aim was to test the hypothesis that repeated administrations of 1×106/kg body weight of allogenic MSCs, that is a significantly lower dosage with respect to the fixed 1×106 MSC used in animal models, can be effective in improving the clinical course of a murine SLE model. METHODS: Bone marrow derived MSCs were obtained from 12-week-old C57BL/6J mice. Seventy-five 8 weeks old female NZ mice were randomly assigned to receive via caudal vein the following alternative treatments: 1) single infusion of 106 MSCs/kg body weight at 18 weeks of age (NZs18) or at at 22 weeks of age (NZs22); 2) multiple monthly infusions of 106 MSCs/kg body weight starting at 18 weeks of age (NZM18) or at 22 weeks of age (NZM22); 3) saline infusions (NZc) Fifteen 8 weeks old C57BL/6J mice (Envigo, Huntingdon, UK) were used as untreated controls (C). Weekly, body weight was recorded and twenty-four hour urines were collected by metabolic cages for each animal; proteinuria was detected by dipstick analysis. At sacrifice, peripheral blood samples were collected from mice and anti-dsDNA antibodies were detected by enzyme immunoassorbent assay (ELISA) method using commercial kits. At sacrifice, kidneys were analyzed for histopathology and immunohistochemical analysis for B220, CD4, MPO, CD4＋Foxp3, F40/80 infiltration was performed. RESULTS: Proteinuria occurrence was delayed NZS and NZM mice, no differences were observed in anti-dsDNA autoantibody titer among the groups at the different time-points; at 36 weeks, no significant differences were observed in term of nephritis scores. Inflammatory cells deposition (MPO and F4/80 positive cells) in NZM was significantly higher than in NZ and NZS. An overexpression of B lymphocytes (B220) was found in NZM while T regulatory cells (CD4＋ Foxp3＋ cells) were reduced in both NZS and NZM with respect to NZc. CONCLUSIONS: Overall, our study failed to show a positive effect of a treatment with murine MSCs in this model and, for some aspects, even deleterious results seem to be observed.

Oncostatin M drives intestinal inflammation and predicts response to tumor necrosis factor-neutralizing therapy in patients with inflammatory bowel disease.

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are complex chronic inflammatory conditions of the gastrointestinal tract that are driven by perturbed cytokine pathways. Anti-tumor necrosis factor-α (TNF) antibodies are mainstay therapies for IBD. However, up to 40% of patients are nonresponsive to anti-TNF agents, which makes the identification of alternative therapeutic targets a priority. Here we show that, relative to healthy controls, inflamed intestinal tissues from patients with IBD express high amounts of the cytokine oncostatin M (OSM) and its receptor (OSMR), which correlate closely with histopathological disease severity. The OSMR is expressed in nonhematopoietic, nonepithelial intestinal stromal cells, which respond to OSM by producing various proinflammatory molecules, including interleukin (IL)-6, the leukocyte adhesion factor ICAM1, and chemokines that attract neutrophils, monocytes, and T cells. In an animal model of anti-TNF-resistant intestinal inflammation, genetic deletion or pharmacological blockade of OSM significantly attenuates colitis. Furthermore, according to an analysis of more than 200 patients with IBD, including two cohorts from phase 3 clinical trials of infliximab and golimumab, high pretreatment expression of OSM is strongly associated with failure of anti-TNF therapy. OSM is thus a potential biomarker and therapeutic target for IBD, and has particular relevance for anti-TNF-resistant patients.

Tissue-infiltrating plasma cells are an important source of carboxylesterase 2 contributing to the therapeutic efficacy of prodrugs.

Carboxylesterase 2 (CES-2) is instrumental for conversion of ester-containing prodrugs in cancer treatment. CES-2 expression was analyzed by immunohistochemistry in colorectal cancer (CRC) compared to colonic inflammation as well as in liver and peripheral blood. In CRC, tumor grades showed no correlation with levels of CES-2 expression, which was heterogeneous within these tumors. Cellular infiltrates in the immediate tumor vicinity expressed high levels of CES-2. Thus, tissue adjacent to the tumor was a substantial source of CES-2 with high expression in plasma cells. CES-2(high) plasma cells were abundantly found in the colon of patients with inflammatory bowel disease. CES-2 expression is strong in hepatocytes of normal livers, while CES-2 expression in peripheral blood mononuclear cells of healthy donors was overall low at protein and mRNA levels. In summary, the conversion of ester-containing prodrugs by CES-2 is mainly to occur in the periphery, during liver passage and in the colon after enterohepatic recirculation. We here demonstrated plasma cells as strong producers of CES-2. Further studies should elucidate the role of CES-2(+) plasma cells in intestinal inflammation and cancer.