Cell Transplantation最新文献

The management of granulocytopenia-associated infections is challenging, and a high mortality rate is associated with traditional supportive therapies. Neutrophils-the primary defenders of the human immune system-have potent bactericidal capabilities. Here, we investigated the dynamic in vivo distribution of neutrophil transfusion and their impact on the treatment outcome of severe granulocytopenic infections. We transfused ⁸⁹Zr-labeled neutrophils in the C57BL/6 mice and observed the dynamic neutrophil distribution in mice for 24 h using the micro-positron emission tomography (Micro-PET) technique. The labeled neutrophils were predominantly retained in the lungs and spleen up to 4 h after injection and then redistributed to other organs, such as the spleen, liver, and bone marrow. Neutrophil transfusion did not elicit marked inflammatory responses or organ damage in healthy host mice. Notably, allogeneic neutrophils showed rapid chemotaxis to the infected area of the host within 1 h. Tail vein infusion of approximately 10⁷ neutrophils substantially bolstered host immunity, ameliorated the inflammatory state, and increased survival rates in neutrophil-depleted and infected mice. Overall, massive allogeneic neutrophil transfusion had a therapeutic effect in severe infections and can have extensive applications in the future.

Pulmonary fibrosis is a complex and multifactorial condition that involves a cascade of events, including lung injury, damage of alveolar epithelial cells (AECs), generation of immune cell-driven inflammation, and activation of fibroblasts and their differentiation into myofibroblasts, resulting in the excessive production and deposition of collagen and progressive scarring and fibrosis of the lung tissue. As lung fibrosis advances, the scarring and stiffening of lung tissue can significantly hinder the exchange of oxygen and carbon dioxide, potentially leading to respiratory failure that can be life-threatening. Anti-inflammatory and immunosuppressive drugs are used to slow down the progression of the disease, manage symptoms, and enhance the patient's quality of life. However, prolonged immunosuppression could increase the susceptibility to severe bacterial, viral, or fungal pneumonia in lung-transplant recipients. Therefore, there is an urgent need for new therapeutic agents that can effectively reduce lung inflammation and fibrosis without compromising the protective immune response in patients with severe lung fibrosis. Results obtained in recently published studies demonstrated that mesenchymal stem/stromal cell-derived microRNAs (MSC-miRNAs) could attenuate detrimental immune response in injured lungs and prevent progression of lung fibrosis. Through the post-transcriptional regulation of target mRNA, MSC-miRNAs modulate protein synthesis and affect viability, proliferation, and cytokine production in AECs, fibroblasts, and lung-infiltrated immune cells. In order to delineate molecular mechanisms responsible for beneficial effects of MSC-miRNAs in the treatment of lung fibrosis, in this review article, we summarized current knowledge related to anti-fibrotic and anti-inflammatory pathways elicited in immune cells, AECs, and myofibroblasts by MSC-miRNAs.

Hepatocyte transplantation (HCT) is a potential bridging therapy or an alternative to liver transplantation. Conventionally, single-cell hepatocytes are injected via the portal vein. This strategy, however, has yet to overcome poor cell engraftment and function. Therefore, we developed an orthotopic HCT method using a liver-derived extracellular matrix (L-ECM) gel. PXB cells (flesh mature human hepatocytes) were dispersed into the hydrogel solution in vitro, and the gel solution was immediately gelated in 37°C incubators to investigate the affinity between mature human hepatocyte and the L-ECM gel. During the 3-day cultivation in hepatocyte medium, PXB cells formed cell aggregates via cell-cell interactions. Quantitative analysis revealed human albumin production in culture supernatants. For the in vivo assay, PXB cells were encapsulated in the L-ECM gel and transplanted between the liver lobes of normal rats. Pathologically, the L-ECM gel was localized at the transplant site and retained PXB cells. Cell survival and hepatic function marker expression were verified in another rat model wherein thioacetamide was administered to induce liver fibrosis. Moreover, cell-cell interactions and angiogenesis were enhanced in the L-ECM gel compared with that in the collagen gel. Our results indicate that L-ECM gels can help engraft transplanted hepatocytes and express hepatic function as a scaffold for cell transplantation.

With the aging population, the incidence of degenerative diseases such as dementia and arthritis is on the rise. To combat these diseases, cell therapies using induced pluripotent stem cells (iPSCs) are being developed worldwide. However, challenges such as high development costs and immune compatibility persist. Thus, methods such as generating patient-specific iPSCs or genetically edited iPSCs with deleted immune-related genes are being researched. Applying these approaches is limited due to high cost and safety concerns of gene editing. Therefore, we focused on an alternative method using human leukocyte antigen (HLA)-homozygous cell lines, which could overcome immune rejection issues economically. We investigated diseases that could potentially be treated with cell therapy and identified which HLA-homozygous cell lines could be most effectively used for the efficient production of therapeutic cell lines. The results of the study showed that cell therapy could be applied to a wide range of diseases, and expanding the population that can benefit from HLA-homozygous iPSC lines could help popularize these treatment methods. We highlight the necessity of a global HLA-homozygous iPSC bank.

Bone morphogenetic protein-2 (BMP-2) has been commercially approved by the Food and Drug Administration for use in bone defects and diseases. BMP-2 promotes osteogenic differentiation of mesenchymal stem cells. In bone tissue engineering, BMP-2 incorporated into scaffolds can be used for stimulating bone regeneration in organoid construction, drug testing platforms, and bone transplants. However, the high dosage and uncontrollable release rate of BMP-2 challenge its clinical application, mainly due to the short circulation half-life of BMP-2, microbial contamination in bone extracellular matrix hydrogel, and the delivery method. Moreover, in clinical translation, the requirement of high doses of BMP-2 for efficacy poses challenges in cost and safety. Based on these, novel strategies should ensure that BMP-2 is delivered precisely to the desired location within the body, regulating the timing of BMP-2 release to coincide with the bone healing process, as well as release BMP-2 in a controlled manner to optimize its therapeutic effect and minimize side effects. This review highlights improvements in bone tissue engineering applying spatiotemporal and controlled BMP-2 delivery, including molecular engineering, biomaterial modification, and synergistic therapy, aiming to provide references for future research and clinical trials.

Post-allogeneic hematopoietic cell transplant (HCT) immunosuppression regimens are given as graft-versus-host disease (GVHD) prophylaxis. Most GVHD prophylaxis regimens are based on calcineurin inhibitors (CNIs). Unfortunately, CNIs are associated with significant associated morbidity, frequently cannot be tolerated, and often need to be discontinued. There is no consensus as to which alternative immunosuppression should be used in cases where CNIs have to be permanently discontinued. Cytotoxic T-lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) blocking agents are well tolerated and have been used extensively in patients with autoimmune disease and as post-transplant immunosuppression. There are two CTLA4-Ig agents: belatacept and abatacept. Belatacept is routinely used in adult kidney transplantation to prevent rejection and abatacept has been approved by the Food and Drug Administration (FDA) for GVHD prophylaxis in patients undergoing a matched or one allele-mismatched unrelated allogenic HCT. Herein, we describe a case in which abatacept was given off-label to replace tacrolimus GVHD prophylaxis in a patient with neurotoxicity undergoing haploidentical HCT. This case suggests that CTLA4-Ig blockade may be a good alternative to a CNI in cases where the CNI needs to be discontinued and warrants further investigation.

Because there is a shortage of donor kidneys, researchers are exploring the possibility of using genetically modified pig kidneys for transplantation. Approaches involving knockout of carbohydrate genes or knockin of protective proteins have been attempted to determine the best gene modifications. In this study, we utilized GalT^-/-;hCD39;hCD55 and GalT^-/-;hCD39;hCD46;hCD55;thrombomodulin (TBM) pigs for transplantation in nonhuman primates (NHPs). The NHPs survived for 4 weeks after kidney transplantation (4 WAT) from the GalT^-/-;hCD39;hCD55 pig and for 6 WAT from the GalT^-/-;hCD39;hCD46;hCD55;TBM pig. However, messenger RNA (mRNA) sequencing and immunohistochemistry analysis revealed that the 6 WAT kidney exhibited more severe apoptosis, inflammation, loss of renal function, and renal fibrosis than the 4 WAT kidney. These results indicate that additional knockin of complement regulator (hCD46) and coagulation regulator (TBM) is not enough to prevent renal damage, suggesting that improved immune suppression is needed for more prolonged survival.

No radical treatment is available for the regeneration of dysfunction and defects in airway epithelia. Artificial tracheae made of polypropylene and collagen sponge were used in clinical studies to reconstitute tracheae after resection. For early epithelialization of the luminal surface of the artificial trachea, a model was established, that is, an artificial trachea covered with human-induced pluripotent stem cell-derived airway epithelial cells (hiPSC-AECs) was transplanted into a tracheal defect in an immunodeficient rat. Unlike the cell types of hiPSC-derived cells that are currently used in clinical studies, AECs maintain tissues by proliferation and differentiation of basal cells into various cell types that constitute AECs constantly. Therefore, post-transplantation, the proportion of each cell type, such as ciliated and goblet cells, may change; however, no studies have examined this possibility. In this study, using our hiPSC-AEC-transplanted rat model, we investigated changes in the proportion of each cell type in hiPSC-AECs pre-transplantation and post-transplantation. As a result, the proportion of each cell type changed post-transplantation. The proportion of ciliated, basal, and club cells increased, and the proportion of goblet cells decreased post-transplantation. In addition, the proportion of each cell type in engrafted hiPSC-AECs is more similar to the proportion of each cell type in normal proximal airway tissue than the proportion of each cell type pre-transplantation. The results of this study are useful for the development of therapeutic techniques using hiPSC-AEC transplantation.

Peritoneal dialysis (PD) is a well-established renal replacement therapy commonly employed in clinical practice. While its primary application is in the treatment of kidney disease, its potential in addressing other systemic disorders, including neurological diseases, has garnered increasing interest. This study provides a comprehensive overview of the related technologies, unique advantages, and clinical applications of PD in the context of neurological disorders. By exploring the mechanism underlying PD, its application in neurological diseases, and associated complications, we addressed the feasibility and benefits of PD as an adjunct therapy for various neurological conditions. Our study aims to highlight its role in detoxification and symptom management, as well as its advantages over other universally accepted methods of renal replacement therapy. Our goal is to bring to the spotlight the therapeutic potential of PD in neurological diseases, such as stroke, stimulate further research, and broaden the scope of its application in the clinical setting.