Donor Regulatory T-Cell Therapy to Prevent Graft-Versus-Host Disease.

Allogeneic hematopoietic cell transplantation (HCT) is a curative therapy limited by graft-versus-host disease (GVHD). In preclinical studies and early-phase clinical studies enrichment of donor regulatory T cells (Tregs) appears to prevent GVHD and promote healthy immunity.We enrolled 44 patients on an open-label, single-center, phase 2 efficacy study investigating if a precision selected and highly purified Treg cell therapy manufactured from donor mobilized peripheral blood improves one-year GVHD-free relapse free survival (GRFS) after myeloablative conditioning (trial NCT01660607).

Single-center randomized trial of T-reg graft alone vs T-reg graft plus tacrolimus for the prevention of acute GVHD.

Allogeneic hematopoietic cell transplantation (HCT) is a curative therapy for hematological malignancies for which graft-versus-host disease (GVHD) remains a major complication. The use of donor T-regulatory cells (Tregs) to prevent GVHD appears promising, including in our previous evaluation of an engineered graft product (T-reg graft) consisting of the timed, sequential infusion of CD34+ hematopoietic stem cells and high-purity Tregs followed by conventional T cells. However, whether immunosuppressive prophylaxis can be removed from this protocol remains unclear.

Immunoregulatory effects of RGMb in gut inflammation.

Graft-versus-host disease (GvHD) is a major complication after allogeneic hematopoietic cell transplantation (HCT). Current strategies to prevent GvHD with immunosuppressive drugs carry significant morbidity and may affect the graft-versus-tumor (GVT) effect. Inflammatory bowel disease (IBD) is an intestinal inflammatory condition that affects more than 2 million people in the United States.

Hyaluronan synthesis inhibition impairs antigen presentation and delays transplantation rejection.

A coat of pericellular hyaluronan surrounds mature dendritic cells (DC) and contributes to cell-cell interactions. We asked whether 4-methylumbelliferone (4MU), an oral inhibitor of HA synthesis, could inhibit antigen presentation. We find that 4MU treatment reduces pericellular hyaluronan, destabilizes interactions between DC and T-cells, and prevents T-cell proliferation in vitro and in vivo.

High-parametric evaluation of human invariant natural killer T cells to delineate heterogeneity in allo- and autoimmunity.

Human invariant natural killer T (iNKT) cells are a rare innate-like lymphocyte population that recognizes glycolipids presented on CD1d. Studies in mice have shown that these cells are heterogeneous and are capable of enacting diverse functions, and the composition of iNKT cell subsets can alter disease outcomes. In contrast, far less is known about how heterogeneity in human iNKT cells relates to disease.

Transplantation of donor grafts with defined ratio of conventional and regulatory T cells in HLA-matched recipients.

BACKGROUNDIn preclinical murine and early clinical studies of hematopoietic cell transplantation, engineering of donor grafts with defined ratios of CD4+CD25+FoxP3+ Tregs to conventional T cells (Tcons) results in the prevention of graft-versus-host disease and improved immune reconstitution. The use of highly purified primary graft Tregs for direct cell infusion has potential advantages over impure immunomagnetic selection or culture expansion, but has not been tested clinically. We performed a phase I study of the timed addition of CD34-selected hematopoietic stem cells and Tregs, followed by Tcons for the treatment of patients with high-risk hematological malignancies.

Donor-Derived Cytokine-Induced Killer Cell Infusion as Consolidation after Nonmyeloablative Allogeneic Transplantation for Myeloid Neoplasms.

Non-myeloablative conditioning, such as with total lymphoid irradiation and antithymocyte globulin (TLI-ATG), has allowed allogeneic hematopoietic cell transplantation (allo-HCT) with curative potential for older patients and those with comorbid medical conditions with myeloid neoplasms. However, early achievement of full donor chimerism (FDC) and relapse remain challenging. Cytokine-induced killer (CIK) cells have been shown to have antitumor cytotoxicity.

4-Methylumbelliferyl glucuronide contributes to hyaluronan synthesis inhibition.

4-Methylumbelliferone (4-MU) inhibits hyaluronan (HA) synthesis and is an approved drug used for managing biliary spasm. However, rapid and efficient glucuronidation is thought to limit its utility for systemically inhibiting HA synthesis. In particular, 4-MU in mice has a short half-life, causing most of the drug to be present as the metabolite 4-methylumbelliferyl glucuronide (4-MUG), which makes it remarkable that 4-MU is effective at all.

Functionalized cyclopropenes as bioorthogonal chemical reporters.

Chemical reporters are unique functional groups that can be used to label biomolecules in living systems. Only a handful of broadly applicable reporters have been identified to date, owing to the rigorous demands placed on these functional groups in biological settings. We describe here a new chemical reporter-cyclopropene-that can be used to target biomolecules in vitro and in live cells.