Divergent Roles of Salmonella Pathogenicity Island 2 and Metabolic Traits during Interaction of S. enterica Serovar Typhimurium with Host Cells

The molecular mechanisms of virulence of the gastrointestinal pathogen Salmonella enterica are commonly studied using cell culture models of infection. In this work, we performed a direct comparison of the interaction of S. enterica serovar Typhimurium (S. Typhimurium) with the non-polarized epithelial cell line HeLa, the polarized cell lines CaCo2, T84 and MDCK, and macrophage-like RAW264.7 cells. The ability of S. Typhimurium wild-type and previously characterized auxotrophic mutant strains to enter host cells, survive and proliferate within mammalian cells and deploy the Salmonella Pathogenicity Island 2-encoded type III secretion system (SPI2-T3SS) was quantified. We found that the entry of S. Typhimurium into polarized cells was much more efficient than entry into non-polarized cells or phagocytic uptake. While SPI2-T3SS dependent intracellular proliferation was observed in HeLa and RAW cells, the intracellular replication in polarized cells was highly restricted and not affected by defective SPI2-T3SS. The contribution of aromatic amino acid metabolism and purine biosynthesis to intracellular proliferation was distinct in the various cell lines investigated. These observations indicate that the virulence phenotypes of S. Typhimurium are significantly affected by the cell culture model applied

Treatment of relapsing mild-to-moderate ulcerative colitis with the probiotic VSL#3 as adjunctive to a standard pharmaceutical treatment: a double-blind, randomized, placebo-controlled study

JECTIVES: VSL#3 is a high-potency probiotic mixture that has been used successfully in the treatment of pouchitis. The primary end point of the study was to assess the effects of supplementation with VSL#3 in patients affected by relapsing ulcerative colitis (UC) who are already under treatment with 5-aminosalicylic acid (ASA) and/or immunosuppressants at stable doses. METHODS: A total of 144 consecutive patients were randomly treated for 8 weeks with VSL#3 at a dose of 3,600 billion CFU/day (71 patients) or with placebo (73 patients). RESULTS: In all, 65 patients in the VSL#3 group and 66 patients in the placebo group completed the study. The decrease in ulcerative colitis disease activity index (UCDAI) scores of 50% or more was higher in the VSL#3 group than in the placebo group (63.1 vs. 40.8; per protocol (PP) P=0.010, confidence interval (CI)??(%) 0.51-0.74; intention to treat (ITT) P=0.031, CI??(%) 0.47-0.69). Significant results with VSL#3 were recorded in an improvement of three points or more in the UCDAI score (60.5% vs. 41.4%; PP P=0.017, CI??(%) 0.51-0.74; ITT P=0.046, CI??(%) 0.47-0.69) and in rectal bleeding (PP P=0.014, CI??(%) 0.46-0.70; ITT P=0.036, CI??(%) 0.41-0.65), whereas stool frequency (PP P=0.202, CI??(%) 0.39-0.63; ITT P=0.229, CI??(%) 0.35-0.57), physician's rate of disease activity (PP P=0.088, CI??(%) 0.34-0.58; ITT P=0.168, CI??(%) 0.31-0.53), and endoscopic scores (PP P=0.086, CI??(%) 0.74-0.92; ITT P=0.366, CI??(%) 0.66-0.86) did not show statistical differences. Remission was higher in the VSL#3 group than in the placebo group (47.7% vs. 32.4%; PP P=0.069, CI??(%) 0.36-0.60; ITT P=0.132, CI??(%) 0.33-0.56). Eight patients on VSL#3 (11.2%) and nine patients on placebo (12.3%) reported mild side effects. CONCLUSIONS: VSL#3 supplementation is safe and able to reduce UCDAI scores in patients affected by relapsing mild-to-moderate UC who are under treatment with 5-ASA and/or immunosuppressants. Moreover, VSL#3 improves rectal bleeding and seems to reinduce remission in relapsing UC patients after 8 weeks of treatment, although these parameters do not reach statistical significance

Horizontal transfer of whole mitochondria restores tumorigenic potential in mitochondria! DNA-deficient cancer cells

Recently, we showed that generation of tumours in syngeneic mice by cells devoid of mitochondrial (mt) DNA (ρ0 cells) is linked to the acquisition of the host mtDNA. However, the mechanism of mtDNA movement between cells remains unresolved. To determine whether the transfer of mtDNA involves whole mitochondria, we injected B16ρ0 mouse melanoma cells into syngeneic C57BL/6Nsu9-DsRed2 mice that express red fluorescent protein in their mitochondria. We document that mtDNA is acquired by transfer of whole mitochondria from the host animal, leading to normalisation of mitochondrial respiration. Additionally, knockdown of key mitochondrial complex I (NDUFV1) and complex II (SDHC) subunits by shRNA in B16ρ0 cells abolished or significantly retarded their ability to form tumours. Collectively, these results show that intact mitochondria with their mtDNA payload are transferred in the developing tumour, and provide functional evidence for an essential role of oxidative phosphorylation in cancer

Real-life efficacy and safety of Ustekinumab as second- or third-line therapy in Crohn’s disease: Results from a large Italian cohort study

OBJECTIVE: Ustekinumab (UST) is an anti-IL12/23 antibody for the treatment of Crohn’s Disease (CD). The aim of this study was to compare the efficacy and safety of UST in a large population-based cohort of CD patients who failed previous treatment with other biologics. PATIENTS AND METHODS: 194 CD patients (108 males and 86 females, mean age 48 years (range 38-58 years) were retrospectively reviewed. 147 patients were already treated with anti-TNFα (75.8%), and 47 (24.2%) patients were already treated with anti-TNFα and vedolizumab. Concomitant treatment with steroids was present in 177 (91.2%) patients. RESULTS: At week 12, clinical remission was achieved in 146 (75.2%) patients. After a mean follow-up of 6 months, clinical remission was maintained in 135 (69.6%) patients; at that time, mucosal healing was assessed in 62 (31.9%) patients, and it was achieved in 33 (53.2) patients. Three (1.5%) patients were submitted to surgery. Steroid-free remission was achieved in 115 (59.3%) patients. Both serum C-Reactive Protein and Fecal Calprotectin (FC) levels were significantly reduced with respect to baseline levels during follow-up. A logistic regression, UST therapy as third-line therapy (after both anti-TNFα and vedolizumab), FC >200 µg/g, and HBI ≥8 were significantly associated with lack of remission. Adverse events occurred in 5 (2.6%) patients, and four of them required suspension of treatment. CONCLUSIONS: UST seemed to be really effective and safe in CD patients unresponsive to other biologic treatments, especially when used as second-line treatment

Hydrogen sulfide inhibits IL-8 expression in human keratinocytes via MAP kinase signaling

Sulfur is able to penetrate the skin, and a sulfur-rich balneotherapy has been suggested to be effective in the treatment of psoriasis. Psoriasis is now considered a genetically programmed, immune-mediated, inflammatory disease, in which intralesional T lymphocytes trigger keratinocytes to proliferate and perpetuate the disease process. Interleukin (IL)-17 and IL-22 produced by Th1/Th17 lymphocytes induce IL-8 secretion by keratinocytes, a key event in the pathogenesis of the disease. It is now clear that mitogen-activated protein kinase (MAPK) (extracellular signal-regulated kinases (ERK) 1 and 2) activity is required for IL-17-induced IL-8 synthesis by keratinocytes, and, in fact, MAPK activity is increased in lesional psoriatic skin. Here, we demonstrate both in vitro and in vivo on primary psoriatic lesions that pharmacological inhibitors of ERKs as well as hydrogen sulfide not only reduce the basal expression and secretion of IL-8, but also interfere with IL-17- and IL-22-induced IL-8 production. These observations, together with the known anti-inflammatory activity of H2S, are relevant to understanding some previously unexplained biological effects exerted by sulfur therapy

Use of tofacitinib as first or second-line therapy is associated with better outcomes in patients with ulcerative colitis: data from a real-world study

Background: Data regarding the real-world (RW) use of tofacitinib (TOF) in patients with ulcerative colitis (UC) are limited. We aimed to investigate TOF’s RW efficacy and safety in Italian UC patients. Research design and methods: A retrospective assessment of clinical and endoscopic activity was performed according to the Mayo score. The primary endpoints were to evaluate the effectiveness and safety of TOF. Results: We enrolled 166 patients with a median follow-up of 24 (IQR 8–36) weeks. Clinical remission was achieved in 61/166 (36.7%) and 75/166 (45.2%) patients at 8-week and 24-week follow-ups, respectively. The optimization was requested in 27 (16.3%) patients. Clinical remission was achieved more frequently when TOF was used as a first/second line rather than a third/fourth line treatment (p = 0.007). Mucosal healing was reported in 46% of patients at the median follow-up time. Colectomy occurred in 8 (4.8%) patients. Adverse events occurred in 12 (5.4%) patients and severe in 3 (1.8%). One case of simple Herpes Zoster and one of renal vein thrombosis were recorded. Conclusions: Our RW data confirm that TOF is effective and safe in UC patients. It performs remarkably better when used as the first/second line of treatment