Xenotransplantation最新文献

Background: Xenotransplantation-the transplantation of living cells, tissues, or organs from animals to humans-has the potential to help overcome the global shortage of human donor organs. However, its success depends on public and professional acceptance, which may vary across cultural and religious contexts. This study evaluated the attitudes of key stakeholders in Turkey, including healthcare providers, kidney transplant recipients, and dialysis patients, toward kidney xenotransplantation.

Methods: A cross-sectional survey was conducted in Turkey among 405 participants: 197 healthcare providers, 114 kidney transplant recipients (KTRs), and 94 dialysis patients. Attitudes toward kidney xenotransplantation were assessed using a 32-item questionnaire. Multivariate logistic regression was used to identify predictors of acceptance.

Results: Overall acceptance was highest when xenotransplantation outcomes were equivalent to human transplants, and substantially lower when outcomes were inferior. Religious appropriateness was the strongest independent predictor of acceptance in both scenarios. For equal outcomes, additional predictors included higher education, lower perceived risk, and male gender. For inferior outcomes, greater acceptance was associated with male gender and being a dialysis patient. Awareness of xenotransplantation remained limited, but over 65% expressed interest in learning more. While concerns about immunologic rejection and infection were common, fear of social stigma was relatively low.

Conclusions: In this predominantly Muslim population, kidney xenotransplantation acceptance is shaped by religious beliefs, gender, education level, risk perception, and patient status. Culturally sensitive communication and targeted education-especially addressing religious and safety concerns-may be essential for promoting informed acceptance of xenotransplantation.

Background: The shortage of human organs for transplantation is a pressing global issue, propelling interest in xenotransplantation as a viable alternative. This study aims to assess the knowledge, attitudes, and practices (KAP) of healthcare workers in Saudi Arabia regarding xenotransplantation, particularly in light of recent advancements in the field.

Methods: A cross-sectional electronic survey was conducted from June 5 to June 19, 2024, targeting Healthcare workers across various specialties in Saudi Arabia. A minimum sample size of 386 participants was determined, and data were collected using a validated survey administered via SurveyMonkey. Descriptive statistics, Chi-square tests, t-tests, and logistic regression analyses were performed to evaluate associations and identify predictors of KAP.

Results: A total of 2689 healthcare workers participated in the survey. The majority were female (58.6%) and under 25 years old (62.6%). The overall knowledge score was moderate (mean = 4.69/9), while attitudes toward xenotransplantation reflected low to moderate acceptance (mean = 2.1/5). Awareness of Islamic approval for human organ transplantation was noted in 57.3% of participants, with only 45.4% expecting future approval for xenotransplantation. Perceived barriers included psychological risks, social stigma, and ethical concerns.

Conclusion: This study highlights the need for enhanced education and engagement among Healthcare workers regarding xenotransplantation in Saudi Arabia. Understanding local attitudes is crucial for the successful implementation of xenotransplantation technologies, considering the unique cultural and ethical landscape of the region. Further research is warranted to explore the implications of these findings for policy and practice in xenotransplantation.

Immunodeficient large animals that allow engraftment of human tissues and cells are highly valuable for translational studies. Recently, a strain of immunodeficient pigs (termed RGD pigs) was developed through the genetic inactivation of RAG1, IL2RG, and CD47. These RGD pigs lack functional T, B, and NK cells and do not exhibit CD47-SIRPα incompatibility-triggered macrophage xenoresponses. Transplantation of human hematopoietic stem/progenitor cells (HSPCs) into RGD pigs results in high levels of durable human hematopoietic engraftment and systemic repopulation with multilineage human lymphohematopoietic cells, including T, B, NK, and myeloid cells. The transplanted pigs maintain robust human hematopoiesis in the bone marrow (BM) and ongoing thymopoiesis in the thymus. Human T and B cells developing in these pigs express broad antigen receptor repertoires and exhibit tolerance to the recipient pig. The RGD pig is considered a valuable preclinical model for investigating normal or diseased human hematopoiesis and related therapies, and offers a potential bioreactor for large-scale production of human immune cells. These pigs are also highly valuable for in vivo studies on other types of human tissues and cells.

Background: Porcine-to-human islet xenotransplantation offers a promising solution to type 1 diabetes. This study investigates the use of Belimumab, a human monoclonal antibody that inhibits B cell activating factor (BAFF) as part of an immunosuppressive regimen in porcine-to-non-human primate xenotransplantation.

Methods: Porcine islets were transplanted into Rhesus monkeys with an immunosuppressant regimen. Blood samples were collected from the monkeys pre- and post-treatment, and single-cell RNA sequencing was performed to investigate immune cell landscape changes, focusing on B cells.

Results: UMAP clustering of B cells identified five distinct subsets. Notably, Belimumab treatment significantly reduced the proportion of both CXCR5⁺ and CXCR5^- atypical memory B cells, which possess the potential to differentiate into antibody-secreting cells. Furthermore, differentially expressed gene (DEG) analysis revealed a comprehensive functional impairment, along with significant downregulation of activation markers such as CD69 and CD83, across all B cell subsets.

Conclusions: Our study elucidates the mechanism of action of Belimumab in non-human primate models, serving as preclinical subjects for B-cell-targeted therapy research in a xenotransplantation context. Significantly, our data indicate that Belimumab not only reduces the proportion of antibody-secreting atypical memory B cells but also induces functional impairment across all B cell subsets. Given the potential pathogenic roles of atypical memory B cells in autoimmunity and other related settings, their reduction by Belimumab could play a crucial role in regulating B-cell-mediated immune responses in pig-to-non-human primate pancreatic islet xenotransplantation. Thus, our findings highlight the prospective utility of Belimumab as a B cell suppressant in future clinical xenotransplantation applications.

Clinical gene-edited pig organ xenotransplantation has recently become a reality, but some problems remain. The transgenic expression of human complement-regulatory proteins in the pig organs is now an accepted means of reducing the impact of complement activation, and immunosuppressive therapy based on CD40/CD154 co-stimulation pathway blockade has proven a largely effective regimen. However, the potential role of complement inhibitors remains uncertain. The complement cascade is complex and consists of several major pathways (e.g., classical, lectin, alternative, terminal) but with several amplification loops and bypasses. It can be inhibited at several different sites, for example, C1, C3, C5, Factor B, and Factor D. We discuss the effect of the various inhibitors currently available and consider their advantages and disadvantages in relation to xenotransplantation. We tentatively suggest that a C3/C3b complement inhibitor may prove optimal, and that complement inhibition may need to be extended for a prolonged period of time.

Introduction: We aimed to evaluate biophysical compatibility of corneal endothelial cells in genetically-engineered (GE) pigs to identify the best candidate for in vivo nonhuman primate (NHP) study and to collect baseline data for future clinical trials from a biological function perspective.

Methods: Triple or quadruple knock-out (T[Q]KO) pigs with inactivation of α1,3-galactosyltransferase (GGTA1), cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH), β1,4-N-acetylgalactosaminyltransferase (β4GalNT2), and/or isoglobotrihexosylceramide synthase (iGB3s) genes were used in combination with insertion of Human(h) CD55, CD39, CD46, and thrombomodulin (TBM) genes. Twenty-seven eyeballs obtained from 14 GE pigs were used to evaluate the physical parameters and functional properties as a suitable donor. Corneal endothelial cell density (ECD) was serially measured for 7 days in a preservative solution. Doubling time (DT) for EC proliferation and immunofluorescence staining of corneal endothelial pump channels and tight junctional proteins were evaluated.

Results: Mean age of GE pigs was 11.9 months old and mean central corneal thickness was 718.2 µm. Mean ECD loss/week was significantly higher in GE pigs younger than 6 months, which was 55.1%, while it was 8.8% in GE pigs older than 6 months (p < 0.001). T(Q)KO/hCD46/hTBM cornea showed early severe apoptotic or necrotic changes of endothelial cells, whereas other GE corneas did not. Although the mean DT increased in all GE pigs, it showed no difference between the younger and older groups. ZO-1, N-cadherin, ATPase, SLC4A1, and aquaporin 1 were well expressed on endothelial cells regardless of modified gene types.

Conclusion: It suggests that no effect of the added gene was observed on the endothelial cell functional capacities in TKO(QKO) pig corneas, and GE pigs over 6 months old are suitable as corneal transplant donors.

Gene-edited pigs are currently considered the most appropriate donors for cardiac xenotransplantation. Although gene editing has improved donor-recipient compatibility, the effects of gene editing on donor organs, and the comprehensive cellular landscape of different gene-edited pig hearts remain unclear. This study characterized the cardiomyocyte and non-cardiomyocyte cellular landscape of wild-type (WT), alpha 1-3 galactosyltransferase gene knockout (GTKO), and triple gene edited (3GE: GTKO·hCD46·hTBM) porcine hearts using single-nucleus RNA sequencing (snRNA-seq) and single-cell RNA sequencing (scRNA-seq). We identified seven major cell types, including cardiomyocyte, fibroblast, endothelial cell, smooth muscle cell, macrophage, T lymphocyte, and pericyte. Integrative analysis revealed significantly more profound transcriptomic alterations in hearts from 3GE pigs compared to those from GTKO pigs. Cellular heterogeneity within cardiomyocytes and non-cardiomyocytes was identified, and pathological staining validated key sequencing findings. Analyses of cell-to-cell interactions identified the core position of cardiomyocytes and fibroblasts in intercellular communications, alongside the characteristic cellular interactions within each genotype. Transcriptomic differences at the transcriptomic level between porcine and normal human hearts were also compared. Our data revealed key cell subsets potentially involved in immune rejection and cardiac hypertrophy in cardiac xenotransplantation. This approach also provides a foundation for applying transcriptomic analysis to donor pigs with increasingly complex genetic modifications, enabling unbiased documentation of transgene expression and assessment of the impact of multigene engineering on endogenous cardiac gene expression.