Molecular Therapy最新文献

Although CAR T-cell therapy is increasingly used to treat relapsed B-cell acute lymphoblastic leukemia (ALL), 20-30% of patients do not respond, and few clinical predictors of response have been established, especially in the pediatric population. A deeper analysis of CAR T-cell infusion products, along with the apheresis product used as the starting material for CAR T-cell manufacturing, provides valuable insights for predicting clinical outcomes. We analyzed infusion products and CD4/8-selected T-cell starting materials from pediatric and young adult patients on a single-center study with relapsed/refractory B-cell ALL who were undergoing treatment with CD22 CAR T-cells and evaluated differences between T-cells from responders and non-responders (NCT023215612). We found that CAR T-cells from non-responders had a more differentiated T-cell phenotype and overexpressed genes associated with cytotoxicity and exhaustion compared to those of responders. Furthermore, we found that these differences could be tracked back to the apheresis materials prior to CAR T-cell manufacturing. Using flow cytometry-based immunophenotypic markers, we developed a scoring system that distinguished non-responders based on T-cell phenotype at the time of apheresis. These findings can help inform outcomes for patients and providers as well as provide insights into targeted manufacturing changes to optimize CAR T-cell efficacy.

mRNA-based therapeutics delivered via lipid nanoparticles (LNP-mRNA) hold great promise for treating diverse diseases. However, further improvements are needed to refine outcomes in non-vaccine, extrahepatic applications, such as minimizing the mononuclear phagocyte system's (MPS)' rapid clearance and off-target toxicity in undesired tissues. We propose modifying LNP surfaces with the phagocytic cell "don't eat me" signal, CD47, in combination with our previously established antibody-based targeted LNP (tLNP) to create a CD47/tLNP platform with reduced phagocytic clearance and off-target effects, and improved efficiency for cell-specific delivery. We showed that CD47 modification decreased macrophage and hepatic uptake both in vitro and in vivo. Combining CD47 modification with antibodies targeting endothelial cells, T cells, or hematopoietic stem cells (HSCs) increased targeting efficiency up to 3-fold compared to tLNP alone. Enhanced targeting of CD47/tLNP to HSCs with reduced off-targeting enabled the delivery of pro-apoptotic mRNA for HSC depletion as a preconditioning strategy prior to bone marrow transplant. Additionally, CD47-modified LNPs showed diminished inflammatory effects on hepatic tissue and an altered protein corona. Our CD47/tLNP-mRNA platform, with its reduced phagocytic clearance, mitigated inflammatory effects, and enhanced targeted delivery, should further facilitate the development of in vivo mRNA therapeutics.

The skin is the largest organ of the body and forms and serves as the barrier for preventing external material from accessing and damaging internal organs. As the outward interface to the environment, it is accessible for the application of therapeutic agents and cellular and gene therapy represent attractive and promising options to treat severe genetic conditions for which palliation has long been the main stay. However, because of its barrier function, transit across and to the sub-dermal compartment can be challenging. This commentary examines the current approaches of cell and gene therapies for genetic skin disorders. We write this from a local and systemic 'outside and inside' perspective. Delivery from the outside encompasses topical, intradermal, and transdermal strategies for cell and vector delivery and ex vivo cell expansion and grafting. The inside approach details systemic delivery via infusion of cells or agents toward providing benefit to the skin. We use recessive dystrophic epidermolysis bullosa (RDEB) as a representative and paradigmatic disease to showcase these approaches as a means to highlight potential broader applicability to other conditions.

Sickle cell disease (SCD) is a single-gene disorder caused by a point mutation of the β-globin gene, resulting in hemolytic anemia, acute pain, multiorgan damage, and early mortality. Hydroxyurea is a first-line drug therapy that switches sickle-globin to non-pathogenic γ-globin; however, it requires lifelong oral administration. Allogeneic hematopoietic stem cell (HSC) transplantation allows for a one-time cure for SCD, albeit with histocompatibility limitations. Therefore, autologous HSC gene therapy was developed to cure SCD in a single treatment, without HSC donors. Current HSC gene therapy is based on the ex vivo culture of patients' HSCs with lentiviral gene addition and gene editing, followed by autologous transplantation back to the patient. However, the complexity of the treatment process and high costs hinder the universal application of ex vivo gene therapy. Therefore, the development of in vivo HSC gene therapy, where gene therapy tools are directly administered to patients, is desirable to provide a more accessible, cost-effective solution that can cure SCD worldwide. In this review, we discuss current treatments including drug therapies, HSC transplantation, and ex vivo gene therapy, the development of gene therapy tools, and progress toward curative in vivo gene therapy in SCD.

Vascular endothelial growth factor B186 (VEGF-B186), a ligand for VEGF receptor 1 (VEGFR1) and neuropilin (NRP), promotes vascular growth in healthy and ischemic myocardium. However, the mechanisms and signaling of VEGF-B186 to support angiogenesis have remained unclear. We studied the effects of VEGF-B186 and its variant, VEGF-B186R127S, which cannot bind to NRPs, using VEGFR1 tyrosine kinase knockout (TK^-/-) mice to explore the mechanism of VEGF-B186 in promoting vascular growth. Ultrasound-guided adenoviral VEGF-B186, VEGF-B186R127S, and control vector gene transfers were performed into VEGFR1 TK-/- mice hearts. In vitro studies in cardiac endothelial cells and further validation in normal and ischemic pig hearts, as well as in wild-type mice, were conducted. Both VEGF-B186 forms promoted vascular growth in VEGFR1 TK^-/- mouse heart and increased the expression of proangiogenic and hematopoietic factors. Unlike VEGF-A, VEGF-B186 forms induced ER stress via the upregulation of Binding immunoglobulin Protein (BiP) as well as ER stress sensors (ATF6, PERK, IRE1α) through ITGAV and ITGA5 integrins, newly identified receptors for VEGF-B, activating the unfolded protein response (UPR) through XBP1. VEGFR1 and NRP are not essential for VEGF-B186-induced vascular growth. Instead, VEGF-B186 can stimulate cardiac regeneration through RGD-binding integrins and ER stress, suggesting a novel mechanism of action for VEGF-B186.