Cellular therapies for the treatment of immune-mediated GI and liver disease

Assessing the immunosuppressive activity of alginate-encapsulated mesenchymal stromal cells on splenocytes

Mesenchymal stromal cells (MSCs) show immunosuppressive effects both via cell-to-cell contact (direct) with immune cells and by producing paracrine factors and extracellular vesicles (indirect). A key challenge in delivering this therapeutic effect in vivo is retaining the MSCs at the site of injection. One way to address this is by encapsulating the MSCs within suitable biomaterial scaffolds. Here, we assess the immunosuppressive effect of alginate-encapsulated murine MSCs on proliferating murine splenocytes. Our results show that MSCs are able to significantly suppress splenocyte proliferation by ∼50% via the indirect mechanism and almost completely (∼98%) via the direct mechanism. We also show for the first time that MSCs as monolayers on tissue culture plastic or encapsulated within alginate, when physically isolated from the splenocytes via transwells, are able to sustain immunosuppressive activity with repeated exposure to fresh splenocytes, for as long as 9 days. These results indicate the need to identify design strategies to simultaneously deliver both modes of MSC immunosuppression. By designing cell-biomaterial constructs with tailored degradation profiles, we can achieve a more sustained (avoiding MSCs migration and apoptosis) and controlled release of both the paracrine signals and eventually the cells themselves enabling efficient MSC-based immunosuppressive therapies for wound healing.

Emerging drugs for the treatment of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a rare immune-mediated cholestatic disease for which no medical therapy has been shown to slow disease progression. Consequently, liver transplantation is the only lifesaving intervention for patients, and despite being a rare disease, PSC is the lead indication for transplantation across several European countries. The vast majority of patients (>70%) also develop inflammatory bowel disease (IBD) at some point in their lifetime, which imparts added lifetime risks of hepatobiliary malignancy and colorectal cancer. The rare disease nature, variable and often slow rates of disease progression (years rather than months), and lack of robust surrogate biomarkers for early stage yet high risk disease, represent critical challenges in trial design that have long precluded the development of effective medical treatment. However, the horizon for new treatments is encouraging, given innovative clinical trial programmes led by industry, alongside several investigator-initiated studies. Herein, we outline the current platform of interventional trials in PSC, before discussing emerging areas of therapeutic interest.

Regulatory Effect of Mesenchymal Stem Cells on T Cell Phenotypes in Autoimmune Diseases

Research on mesenchymal stem cells (MSCs) starts from the earliest assumption that cells derived from the bone marrow have the ability to repair tissues. Several scientists have since documented the crucial role of bone marrow-derived MSCs (BM-MSCs) in processes such as embryonic bone and cartilage formation, adult fracture and tissue repair, and immunomodulatory activities in therapeutic applications. In addition to BM-MSCs, several sources of MSCs have been reported to possess tissue repair and immunoregulatory abilities, making them potential treatment options for many diseases. Therefore, the therapeutic potential of MSCs in various diseases including autoimmune conditions has been explored. In addition to an imbalance of T cell subsets in most patients with autoimmune diseases, they also exhibit complex disease manifestations, overlapping symptoms among diseases, and difficult treatment. MSCs can regulate T cell subsets to restore their immune homeostasis toward disease resolution in autoimmune conditions. This review summarizes the role of MSCs in relieving autoimmune diseases via the regulation of T cell phenotypes.