Background: Human umbilical cord mesenchymal stromal cells (UC-MSCs) have low immunogenicity and immune regulation. To investigate immunomodulatory effects of human UC-MSCs on MHC class II expression and allograft, we transplanted heart of transgenic rats with MHC class II expression on vascular endothelium.
Methods: UC-MSCs were obtained from human umbilical cords and confirmed with flow cytometry analysis. Transgenic rat line was established using the construct of human MHC class II transactivator gene (CIITA) under mouse ICAM-2 promoter control. The induced MHC class II expression on transgenic rat vascular endothelial cells (VECs) was assessed with immunohistological staining. And the survival time of cardiac allograft was compared between the recipients with and without UC-MSC transfusion.
Results: Flow cytometry confirmed that the human UC-MSCs were positive for CD29, CD44, CD73, CD90, CD105, CD271, and negative for CD34 and HLA-DR. Repeated infusion of human UC-MSCs reduced MHC class II expression on vascular endothelia of transplanted hearts, and increased survival time of allograft. The UC-MSCs increased regulatory cytokines IL10, transforming growth factor (TGF)-β1 and suppressed proinflammatory cytokines IL2 and IFN-γ in vivo. The UC-MSC culture supernatant had similar effects on cytokine expression, and decreased lymphocyte proliferation in vitro.
Conclusions: Repeated transfusion of the human UC-MSCs reduced MHC class II expression on vascular endothelia and prolonged the survival time of rat cardiac allograft.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4132141 | PMC |
Am J Respir Cell Mol Biol
January 2025
Wayne State University, Division of Pulmonary, Critical Care and Sleep Medicine, Detroit, Michigan, United States;
Numerous chronic human disorders are associated with immune activation by obscure antigen(s). We identified a novel sarcoidosis-epitope (ChainA) by immunoscreening of a novel T7 phage library and confirmed an abundance of ChainA IgG-antibody in sarcoidosis. We tested whether ChainA epitope elicits immune responses through B-cell activation, plasma cell differentiation and antibody production.
View Article and Find Full Text PDFFront Immunol
January 2025
Institute for Immunodeficiency, Center for Chronic Immunodeficiency (CCI), Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Introduction: Human Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4) insufficiency caused by heterozygous germline mutations in is a complex immune dysregulation and immunodeficiency syndrome presenting with reduced penetrance and variable disease expressivity, suggesting the presence of disease modifiers that trigger the disease onset and severity. Various genetic and non-genetic potential triggers have been analyzed in CTLA-4 insufficiency cohorts, however, none of them have revealed a clear association to the disease. Multiple HLA haplotypes have been positively or negatively associated with various autoimmune diseases and inborn errors of immunity (IEI) due to the relevance of MHC in the strength of the T cell responses.
View Article and Find Full Text PDFCell Host Microbe
January 2025
Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, Saint Louis, MO 63110, USA. Electronic address:
Here, we explore the relationship between dietary fibers, colonic epithelium major histocompatibility complex class II (MHC-II) expression, and immune cell interactions in regulating susceptibility to Clostridioides difficile infection (CDI). We find that a low-fiber diet increases MHC-II expression in the colonic epithelium, which, in turn, worsens CDI by promoting the development of pathogenic CD4 intraepithelial lymphocytes (IELs). The influence of dietary fibers on MHC-II expression is mediated by its metabolic product, acetate, and its receptor, free fatty acid receptor 2 (FFAR2).
View Article and Find Full Text PDFClin Epigenetics
January 2025
School of Biomedical Sciences and Pharmacy, The University of Newcastle, Callaghan, NSW, 2308, Australia.
Background: Hypomethylating agents (HMA), such as azacytidine (AZA) and decitabine (DAC), are epigenetic therapies used to treat some patients with acute myeloid leukaemia (AML) and myelodysplastic syndrome. HMAs act in a replication-dependent manner to remove DNA methylation from the genome. However, AML cells targeted by HMA therapy are often quiescent within the bone marrow, where oxygen levels are low.
View Article and Find Full Text PDFNat Cancer
January 2025
Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
Cancer cells frequently rewire their metabolism to support proliferation and evade immune surveillance, but little is known about metabolic targets that could increase immune surveillance. Here we show a specific means of mitochondrial respiratory complex I (CI) inhibition that improves tumor immunogenicity and sensitivity to immune checkpoint blockade (ICB). Targeted genetic deletion of either Ndufs4 or Ndufs6, but not other CI subunits, induces an immune-dependent growth attenuation in melanoma and breast cancer models.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!