Background: Delayed rejection of xenografts is a major hurdle that needs to be addressed to achieve long-term engraftment in the pig-to-primate transplant setting. Both vascular and avascular xenografts are susceptible to a delayed rejection process that comprises humoral and cellular responses. Tumor necrosis factor (TNF) is believed to play a role in this process by promoting cell activation, apoptosis and the recruitment of inflammatory cells. To address this problem, we engineered the donor cell in such a way that it could block both human and porcine TNF.
Methods: We produced a recombinant fusion protein containing the extracellular domain of the porcine TNF-Receptor 1 and an IgG Fc moiety (pTNFR1Ig). We first evaluated by flow cytometry the pTNFR1Ig capacity to prevent TNF alpha-induced expression of SLAI, SLAII, VCAM-1, ICAM-1 and E-selectin on the cell surface of porcine aortic endothelial cells (PAEC). The effect on TNF alpha-mediated cell death was also assessed by propidium iodide staining after incubating PAEC with TNF alpha plus cycloheximide for 24 h. PAEC and porcine fibroblasts were subsequently engineered by retroviral infection to express and secrete pTNFR1Ig and their resistance to the TNF alpha effects was tested in vitro. Finally, we transplanted mock-control and pTNFR1Ig-expressing PAEC under the kidney capsule of BALB/c mice in the absence of immunosuppression and examined the degree of rejection at 2 and 3 weeks post-transplantation.
Results: Treatment with pTNFR1Ig resulted in a very potent blockade of human, porcine and murine TNF alpha activity on porcine cells. It inhibited the upregulation of all cell surface markers of activation tested as well as the TNF alpha-mediated cell death. Moreover, pTNFR1Ig-expressing PAEC showed prolonged engraftment in a pig-to-mouse xenotransplant model.
Conclusions: Incorporation of strategies that block TNF may prove useful in the development of xenografts resistant to delayed rejection.
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http://dx.doi.org/10.1111/j.1399-3089.2004.00169.x | DOI Listing |
Diabetol Metab Syndr
January 2025
Serviço de Endocrinologia (SEMPR) do Hospital das Clínicas da Universidade Federal do Paraná (UFPR), Curitiba, Brazil.
Background: Type 2 diabetes mellitus (T2D) is a global health concern with a rising prevalence, particularly in Brazil. Insulin therapy plays a crucial role in managing T2D, helping to maintain glucose and energy homeostasis. Moreover, early initiation of insulin is crucial for hyperglycemic control and prevention of chronic complications.
View Article and Find Full Text PDFBackground: In recent years, the increase of the post-transplantation diabetes mellitus (PTDM) after renal transplantation encourages people to do a lot of research on the disease. This paper conducted a bibliometric study on PTDM related literature to explore the risk factors of diabetes after kidney transplantation, as well as the current status, hotspots and development trends of PTDM research, so as to provide reference for researchers in related fields.
Methods: We searched the Web of Science Core Collection (WoSCC) database for PTDM literature from January 1, 1990, to August 20, 2023, and used VOSviewer, CiteSpace, and the R package 'bibliometrix' to do bibliometric analysis.
Clin Transplant
January 2025
Division of Transplant Surgery, Department of Surgery, University of Washington, Seattle, Washington, USA.
Background: The use of donor kidneys with acute kidney injury (AKI) aims to expand the organ pool, but uncertainty remains regarding their outcomes across different Kidney Donor Profile Index (KDPI) groups and preservation methods.
Methods: We retrospectively analyzed 108 160 deceased donor kidney transplants from the OPTN database, focusing on adult recipients of kidneys from donors with or without AKI between December 2014 and December 2022. Propensity matching was used for each KDPI group (1-20, 21-59, 60-84, and 85-100), comparing donors with AKIN stages 0-1 to AKIN stages 2-3.
Transplantation
January 2025
Department of Surgery, Center for Transplantation Sciences, Massachusetts General Hospital, Harvard Medical School, Boston, MA.
Background: Long-term renal allograft acceptance has been achieved in macaques using a transient mixed hematopoetic chimerism protocol, but similar regimens have proven unsuccessful in heart allograft recipients unless a kidney transplant was performed simultaneously. Here, we test whether a modified protocol based on targeting CD154, CD2, and CD28 is sufficient to prolong heart allograft acceptance or promote the expansion of regulatory T cells.
Methods: Eight macaques underwent heterotopic allo-heart transplantation from major histocompatibility complex-mismatched donors.
Cancer Res
December 2024
Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.
Mutations in the exonuclease domains of the replicative nuclear DNA polymerases POLD1 and POLE are associated with increased cancer incidence, elevated tumor mutation burden (TMB), and enhanced response to immune checkpoint blockade (ICB). Although ICB is approved for treatment of several cancers, not all tumors with elevated TMB respond, highlighting the need for a better understanding of how TMB affects tumor biology and subsequently immunotherapy response. To address this, we generated mice with germline and conditional mutations in the exonuclease domains of Pold1 and Pole.
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