BACKGROUND: Increasing evidence indicates that oxidative stress and interferon γ (IFNγ)-driven cellular immune responses are responsible for the pathogenesis of vitiligo. However, the connection between oxidative stress and the local production of IFNγ in early vitiligo remains unexplored. The aim of this study was to identify the mechanism underlying the production of IFNγ by mast cells and its impact on vitiligo pathogenesis. METHODS: Skin specimens from the central, marginal, and perilesional skin areas of active vitiligo lesions were collected to characterize changes of mast cells, CD8 + T cells, and IFNγ-producing cells. Cell supernatants from hydrogen peroxide (H 2 O 2 )-treated keratinocytes (KCs) were harvested to measure levels of soluble stem cell factor (sSCF) and matrix metalloproteinase (MMP)-9. A murine vitiligo model was established using Mas-related G protein-coupled receptor-B2 (MrgB2, mouse ortholog of human MrgX2) conditional knockout (MrgB2 -/- ) mice to investigate IFNγ production and inflammatory cell infiltrations in tail skin following the challenge with tyrosinase-related protein (Tyrp)-2 180 peptide. Potential interactions between the Tyrp-2 180 peptide and MrgX2 were predicted using molecular docking. The siRNAs targeting MrgX2 and the calcineurin inhibitor FK506 were also used to examine the signaling pathways involved in mast cell activation. RESULTS: IFNγ-producing mast cells were closely aligned with the recruitment of CD8 + T cells in the early phase of vitiligo skin. sSCF released by KCs through stress-enhanced MMP9-dependent proteolytic cleavage recruited mast cells into sites of inflamed skin (Perilesion vs . lesion, 13.00 ± 4.00/high-power fields [HPF] vs . 26.60 ± 5.72/HPF, P <0.05). Moreover, IFNγ-producing mast cells were also observed in mouse tail skin following challenge with Tyrp-2 180 (0 h vs . 48 h post-recall, 0/HPF vs . 3.80 ± 1.92/HPF, P <0.05). The IFNγ + mast cell and CD8 + T cell counts were lower in the skin of MrgB2 -/- mice than in those of wild-type mice (WT vs . KO 48 h post-recall, 4.20 ± 0.84/HPF vs . 0.80 ± 0.84/HPF, P <0.05). CONCLUSION Mast cells activated by MrgX2 serve as a local IFNγ producer that bridges between innate and adaptive immune responses against MCs in early vitiligo. Targeting MrgX2-mediated mast cell activation may represent a new strategy for treating vitiligo.
Vitiligo/metabolism* ; Mast Cells/immunology* ; Animals ; Interferon-gamma/metabolism* ; Mice ; Humans ; Melanocytes/metabolism* ; Receptors, G-Protein-Coupled/genetics* ; Mice, Knockout ; Mice, Inbred C57BL ; Male ; Female ; Matrix Metalloproteinase 9/metabolism* ; Stem Cell Factor/metabolism*

OBJECTIVE: To explore the effects of hydroxychloroquine (HCQ) on immune mediators dysregulation in severe infection after chemotherapy in acute myeloid leukemia (AML) and its molecular mechanism. METHODS: Bone marrow or peripheral blood samples of 36 AML patients with severe infection (AML-SI) and 29 AML patients without infection (AML-NI) after chemotherapy were collected from the First Affiliated Hospital of Gannan Medical University from August 2022 to June 2023. In addition, the peripheral blood of 21 healthy subjects from the same period in our hospital was selected as the control group. The mRNA expressions of CXCL12, CXCR4 and CXCR7 were detected by RT-qPCR technology, and the levels of IL-6, IL-8 and TNF-α were detected by ELISA. Leukemia-derived THP-1 cells were selected and constructed as AML disease model. At the same time, bone marrow mesenchymal stem cells (BM-MSCs) from AML-SI patients were co-cultured with THP-1 cells and divided into Mono group and Co-culture group. THP-1 cells were treated with different concentration gradients of HCQ. The cell proliferation activity was subsequently detected by CCK-8 method and apoptosis was detected by Annexin V/PI double staining flow cytometry. ELISA was used to detect the changes of IL-6, IL-8 and TNF-α levels in the supernatant of the cell co-culture system, RT-qPCR was used to detect the mRNA expression changes of the core members of the CXCL12-CXCR4/7 regulatory axis, and Western blot was used to detect the expressions of apoptosis regulatory molecules and related signaling pathway proteins. RESULTS: CXCL12, CXCR4, CXCR7, as well as IL-6, IL-8, and TNF-α were all abnormally increased in AML patients, and the increases were more significant in AML-SI patients (P <0.01). Furthermore, there were statistically significant differences between AML-NI patients and AML-SI patients (all P <0.05). HCQ could inhibit the proliferation and induce the apoptosis of THP-1 cells, but the low concentration of HCQ had no significant effect on the killing of THP-1 cells. When THP-1 cells were co-cultured with BM-MSCs of AML patients, the levels of IL-6, IL-8 and TNF-α in the supernatance of Co-culture group were significantly higher than those of Mono group (all P <0.01). After HCQ intervention, the levels of IL-6, IL-8 and TNF-α in cell culture supernatant of Mono group were significantly decreased compared with those before intervention (all P <0.01). Similarly, those of Co-culture group were also significantly decreased (all P <0.001). However, the expression of the core members of the CXCL12-CXCR4/7 regulatory axis was weakly affected by HCQ. HCQ could up-regulate the expression of pro-apoptotic protein Bax, down-regulate the expression of anti-apoptotic protein Bcl-2, as well as simultaneously promote the hydrolytic activation of Caspase-3 when inhibiting the activation level of TLR4/NF-κB pathway, then induce the programmed death of THP-1 cells after intervention. CONCLUSION The core members of CXCL12-CXCR4/7 axis and related cytokines may be important mediators of severe infectious immune disorders in AML patients. HCQ can inhibit cytokine levels to reverse immune mediators dysregulation and suppress malignant biological characteristics of leukemia cells. The mechanisms may be related to regulating the expression of Bcl-2 family proteins, hydrolytically activating Caspase-3 and inhibiting the activation of TLR4/NF-κB signaling pathway.
Humans ; Leukemia, Myeloid, Acute/immunology* ; Hydroxychloroquine/pharmacology* ; Receptors, CXCR4/metabolism* ; Apoptosis/drug effects* ; Tumor Necrosis Factor-alpha/metabolism* ; Chemokine CXCL12/metabolism* ; Interleukin-8/metabolism* ; Interleukin-6/metabolism* ; Receptors, CXCR/metabolism* ; Mesenchymal Stem Cells ; THP-1 Cells

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.
Adoptive Transfer ; Alveolar Epithelial Cells ; pathology ; Animals ; Apoptosis ; Betacoronavirus ; Body Fluids ; metabolism ; CD4-Positive T-Lymphocytes ; immunology ; Clinical Trials as Topic ; Coinfection ; prevention & control ; therapy ; Coronavirus Infections ; complications ; immunology ; Disease Models, Animal ; Endothelial Cells ; pathology ; Extracorporeal Membrane Oxygenation ; Genetic Therapy ; methods ; Genetic Vectors ; administration & dosage ; therapeutic use ; Humans ; Immunity, Innate ; Inflammation Mediators ; metabolism ; Lung ; pathology ; physiopathology ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stem Cells ; physiology ; Multiple Organ Failure ; etiology ; prevention & control ; Pandemics ; Pneumonia, Viral ; complications ; immunology ; Respiratory Distress Syndrome, Adult ; immunology ; pathology ; therapy ; Translational Medical Research

Cancer stem cells (CSCs), a subpopulation of tumor cells, have self-renewal and multi-lineage differentiation abilities that play an important role in cancer initiation, maintenance, and metastasis. An accumulation of evidence indicates that CSCs can cause conventional therapy failure and cancer recurrence because of their treatment resistance and self-regeneration characteristics. Therefore, approaches that specifically and efficiently eliminate CSCs to achieve a durable clinical response are urgently needed. Currently, treatments with chimeric antigen receptor-modified T (CART) cells have shown successful clinical outcomes in patients with hematologic malignancies, and their safety and feasibility in solid tumors was confirmed. In this review, we will discuss in detail the possibility that CART cells inhibit CSCs by specifically targeting their cell surface markers, which will ultimately improve the clinical response for patients with various types of cancer. A number of viewpoints were summarized to promote the application of CSC-targeted CART cells in clinical cancer treatment. This review covers the key aspects of CSC-targeted CART cells against cancers in accordance with the premise of the model, from bench to bedside and back to bench.
Humans ; Molecular Targeted Therapy ; methods ; Neoplasms ; immunology ; pathology ; therapy ; Neoplastic Stem Cells ; pathology ; Receptors, Chimeric Antigen ; metabolism ; T-Lymphocytes ; immunology ; metabolism ; Translational Medical Research

Currently, the most effective treatment for end-stage liver fibrosis is liver transplantation; however, transplantation is limited by a shortage of donor organs, surgical complications, immunological rejection, and high medical costs. Recently, mesenchymal stem cell (MSC) therapy has been suggested as an effective alternate approach for the treatment of hepatic diseases. MSCs have the potential to differentiate into hepatocytes, and therapeutic value exists in their immune-modulatory properties and secretion of trophic factors, such as growth factors and cytokines. In addition, MSCs can suppress inflammatory responses, reduce hepatocyte apoptosis, increase hepatocyte regeneration, regress liver fibrosis and enhance liver functionality. Despite these advantages, issues remain; MSCs also have fibrogenic potential and the capacity to promote tumor cell growth and oncogenicity. This paper summarizes the properties of MSCs for regenerative medicine and their therapeutic mechanisms and clinical application in the treatment of liver fibrosis. We also present several outstanding risks, including their fibrogenic potential and their capacity to promote pre-existing tumor cell growth and oncogenicity.
Animals ; Cell Differentiation ; Cell Proliferation ; Hepatocytes/immunology/metabolism/pathology/*transplantation ; Humans ; Liver/immunology/metabolism/pathology/physiopathology/*surgery ; Liver Cirrhosis/diagnosis/immunology/metabolism/physiopathology/*surgery ; Liver Regeneration ; *Mesenchymal Stem Cell Transplantation/adverse effects ; *Mesenchymal Stromal Cells/immunology/metabolism/pathology ; Phenotype ; Regenerative Medicine/*methods ; Risk Factors ; Signal Transduction ; Treatment Outcome

Cancer cells and the immune system are closely related and thus influence each other. Although immune cells can suppress cancer cell growth, cancer cells can evade immune cell attack via immune escape mechanisms. Natural killer (NK) cells kill cancer cells by secreting perforins and granzymes. Upon contact with cancer cells, NK cells form immune synapses to deliver the lethal hit. Mature NK cells are differentiated from hematopoietic stem cells in the bone marrow. They move to lymph nodes, where they are activated through interactions with dendritic cells. Interleukin-15 (IL-15) is a key molecule that activates mature NK cells. The adoptive transfer of NK cells to treat incurable cancer is an attractive approach. A certain number of activated NK cells are required for adoptive NK cell therapy. To prepare these NK cells, mature NK cells can be amplified to obtain sufficient numbers of NK cells. Alternatively, NK cells can be differentiated and amplified from hematopoietic stem cells. In addition, the selection of donors is important to achieve maximal efficacy. In this review, we discuss the overall procedures and strategies of NK cell therapy against cancer.
Cell Differentiation ; *Cell- and Tissue-Based Therapy ; Gene Expression Regulation ; Hematopoietic Stem Cells/cytology/metabolism ; Humans ; *Immunotherapy, Adoptive ; Killer Cells, Natural/cytology/*immunology/*metabolism ; Lymphocyte Activation/immunology ; Signal Transduction

Adipose tissue stem cells (ADSCs) would be an attractive autologous cell source. However, ADSCs require invasive procedures, and has potential complications. Recently, urine stem cells (USCs) have been proposed as an alternative stem cell source. In this study, we compared USCs and ADSCs collected from the same patients on stem cell characteristics and capacity to differentiate into various cell lineages to provide a useful guideline for selecting the appropriate type of cell source for use in clinical application. The urine samples were collected via urethral catheterization, and adipose tissue was obtained from subcutaneous fat tissue during elective laparoscopic kidney surgery from the same patient (n = 10). Both cells were plated for primary culture. Cell proliferation, colony formation, cell surface markers, immune modulation, chromosome stability and multi-lineage differentiation were analyzed for each USCs and ADSCs at cell passage 3, 5, and 7. USCs showed high cell proliferation rate, enhanced colony forming ability, strong positive for stem cell markers expression, high efficiency for inhibition of immune cell activation compared to ADSCs at cell passage 3, 5, and 7. In chromosome stability analysis, both cells showed normal karyotype through all passages. In analysis of multi-lineage capability, USCs showed higher myogenic, neurogenic, and endogenic differentiation rate, and lower osteogenic, adipogenic, and chondrogenic differentiation rate compared to ADSCs. Therefore, we expect that USC can be an alternative autologous stem cell source for muscle, neuron and endothelial tissue reconstruction instead of ADSCs.
Adult Stem Cells/*cytology/*immunology/transplantation ; Biomarkers/metabolism ; Cell Differentiation ; Cell Lineage ; Cell Proliferation ; Cell Separation ; Chromosomal Instability ; Colony-Forming Units Assay ; Humans ; Karyotyping ; Multipotent Stem Cells/cytology/immunology/transplantation ; Subcutaneous Fat, Abdominal/*cytology ; Transplantation, Autologous ; Urine/*cytology

Acute graft-versus-host disease (aGVHD) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the mechanisms of aGVHD are not well understood. We aim to investigate the roles of the three angiogenic factors: angiopoietin-1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) in the development of aGVHD. Twenty-one patients who underwent allo-HSCT were included in our study. The dynamic changes of Ang-1, Ang-2 and VEGF were monitored in patients before and after allo-HSCT. In vitro, endothelial cells (ECs) were treated with TNF-β in the presence or absence of Ang-1, and then the Ang-2 level in the cell culture medium and the tubule formation by ECs were evaluated. After allo-HSCT, Ang-1, Ang-2 and VEGF all exhibited significant variation, suggesting these factors might be involved in the endothelial damage in transplantation. Patients with aGVHD had lower Ang-1 level at day 7 but higher Ang-2 level at day 21 than those without aGVHD, implying that Ang-1 may play a protective role in early phase yet Ang-2 is a promotion factor to aGVHD. In vitro, TNF-β promoted the release of Ang-2 by ECs and impaired tubule formation of ECs, which were both weakened by Ang-1, suggesting that Ang-1 may play a protective role in aGVHD by influencing the secretion of Ang-2, consistent with our in vivo tests. It is concluded that monitoring changes of these factors following allo-HSCT might help to identify patients at a high risk for aGVHD.
Acute Disease ; Adolescent ; Adult ; Angiogenesis Inducing Agents ; immunology ; metabolism ; pharmacology ; Angiopoietin-1 ; genetics ; immunology ; pharmacology ; Angiopoietin-2 ; genetics ; immunology ; pharmacology ; Antineoplastic Agents ; therapeutic use ; Female ; Gene Expression Regulation, Neoplastic ; Graft vs Host Disease ; genetics ; immunology ; pathology ; Hematopoietic Stem Cell Transplantation ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; immunology ; Humans ; Leukemia, Myeloid ; genetics ; immunology ; pathology ; therapy ; Lymphoma, Non-Hodgkin ; genetics ; immunology ; pathology ; therapy ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; immunology ; pathology ; therapy ; Retrospective Studies ; Signal Transduction ; Transplantation, Homologous ; Tumor Necrosis Factor-alpha ; pharmacology ; Vascular Endothelial Growth Factor A ; genetics ; immunology

Although mesenchymal stem cells (MSCs) are increasingly used to treat graft-versus-host disease (GVHD), their immune regulatory mechanism in the process is elusive. The present study aimed to investigate the curative effect of third-party umbilical cord blood-derived human MSCs (UCB-hMSCs) on GVHD patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and their immune regulatory mechanism. Twenty-four refractory GVHD patients after allo-HSCT were treated with UCB-hMSCs. Immune cells including T lymphocyte subsets, NK cells, Treg cells and dendritic cells (DCs) and cytokines including interleukin-17 (IL-17) and tumor necrosis factor-alpha (TNF-α) were monitored before and after MSCs transfusion. The results showed that the symptoms of GVHD were alleviated significantly without increased relapse of primary disease and transplant-related complications after MSCs transfusion. The number of CD3(+), CD3(+)CD4(+) and CD3(+)CD8(+) cells decreased significantly, and that of NK cells remained unchanged, whereas the number of CD4(+) and CD8(+) Tregs increased and reached a peak at 4 weeks; the number of mature DCs, and the levels of TNF-α and IL-17 decreased and reached a trough at 2 weeks. It was concluded that MSCs ameliorate GVHD and spare GVL effect via immunoregulations.
Adolescent ; Adult ; Cord Blood Stem Cell Transplantation ; methods ; Cytokines ; metabolism ; Dendritic Cells ; metabolism ; Female ; Graft vs Host Disease ; immunology ; therapy ; Hematopoietic Stem Cell Transplantation ; adverse effects ; Humans ; Immunomodulation ; Killer Cells, Natural ; metabolism ; Male ; T-Lymphocyte Subsets ; metabolism ; Transplantation, Homologous ; adverse effects ; Young Adult

Mesenchymal stem cells (MSCs) have been widely studied for their applications in stem cell-based regeneration. During myocardial infarction (MI), infiltrated macrophages have pivotal roles in inflammation, angiogenesis and cardiac remodeling. We hypothesized that MSCs may modulate the immunologic environment to accelerate regeneration. This study was designed to assess the functional relationship between the macrophage phenotype and MSCs. MSCs isolated from bone marrow and bone marrow-derived macrophages (BMDMs) underwent differentiation induced by macrophage colony-stimulating factor. To determine the macrophage phenotype, classical M1 markers and alternative M2 markers were analyzed with or without co-culturing with MSCs in a transwell system. For animal studies, MI was induced by the ligation of the rat coronary artery. MSCs were injected within the infarct myocardium, and we analyzed the phenotype of the infiltrated macrophages by immunostaining. In the MSC-injected myocardium, the macrophages adjacent to the MSCs showed strong expression of arginase-1 (Arg1), an M2 marker. In BMDMs co-cultured with MSCs, the M1 markers such as interleukin-6 (IL-6), IL-1beta, monocyte chemoattractant protein-1 and inducible nitric oxide synthase (iNOS) were significantly reduced. In contrast, the M2 markers such as IL-10, IL-4, CD206 and Arg1 were markedly increased by co-culturing with MSCs. Specifically, the ratio of iNOS to Arg1 in BMDMs was notably downregulated by co-culturing with MSCs. These results suggest that the preferential shift of the macrophage phenotype from M1 to M2 may be related to the immune-modulating characteristics of MSCs that contribute to cardiac repair.
Animals ; Biomarkers/metabolism ; *Cell Differentiation ; Cells, Cultured ; Coculture Techniques ; Culture Media, Conditioned/pharmacology ; Humans ; *Macrophage Activation ; Macrophage Colony-Stimulating Factor/*pharmacology ; Macrophages/drug effects/*immunology/metabolism ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology/drug effects/metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Myocardial Infarction/surgery ; Rats