cuff-free-suture-based-cervical-model-for-secondary-heterotopic-heart

Cuff-Free Suture-Based Cervical Model for Secondary Heterotopic Heart Transplantation to Evaluate Donor-Specific Immune Tolerance in Mice

Murine heterotopic cardiac transplantation is a well-established model for investigating allograft rejection and immune tolerance. In tolerance studies, ...

Massachusetts General Hospital

Interstitial fibrosis and tubular atrophy (IFTA) with inflammation (IFTA-I) is strongly correlated with kidney allograft failure. Diagnosis of IFTA-I accurately and early is critical to prevent graft failure and improve graft survival. In the current study, through analyzing the renal allograft biopsy in patients with stable function after kidney transplantation (STA), IFTA and IFTA-I group with semi-supervised principal components methods, we found that CD2, IL7R, CCL5 based signature could not only distinguish STA and IFTA-I well, but predict IFTA-I with a high degree of accuracy with an area under the curve (AUC) of 0.91 ( = 0.00023). Additionally, IRF8 demonstrated significant differences among STA, IFTA and IFTA-I groups, suggesting that IRF8 had the capacity to discriminate the different classifications of graft biopsies well. Also, with Kaplan-Meier and log-rank methods, we found that IRF8 could serve as the prognostic marker for renal graft failure in those biopsies without rejection (AUC = 0.75) and the recipients expressing high had a higher risk for renal graft loss ( < 0.0001). This research may provide new targets for therapeutic prevention and intervention for post-transplantation IFTA with or with inflammation.

Profiling of mRNA of interstitial fibrosis and tubular atrophy with subclinical inflammation in recipients after kidney transplantation.

Post-transplant (post-Tx) kidney cancer has become the second-highest cause of death in kidney recipients. Late diagnosis and treatment are the main reasons for high mortality. Further research into early diagnosis and potential treatment is therefore required. In this current study, through genome-wide RNA-Seq profile analysis of post-Tx malignant blood samples and post-Tx non-malignant control blood samples (CTRL-Tx), we found Rap GTPase Interactor (RADIL) and Aprataxin (APTX) to be the most meaningful markers for cancer diagnosis. Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the RADIL-APTX signature model was 0.92 ( < 0.0001). Similarly, the AUC of RADIL alone was 0.91 ( < 0.0001) and that of APTX was 0.81 ( = 0.001). Additionally, using a semi-supervised method, we found that RADIL alone could better predict malignancies in kidney transplantation recipients than APTX alone. Kaplan-Meier analysis indicated that RADIL was expressed significantly higher in the early stages (I and II) of kidney, liver, stomach, and pancreatic cancer, suggesting the potential use of RADIL in early diagnosis. Multivariable Cox regression analysis found that RADIL together with other factors (including age, stage III, stage IV and CD8+ T cells) play a key role in kidney cancer development. Among those factors, RADIL could promote kidney cancer development (HR > 1,  < 0.05) while CD8+ T cells could inhibit kidney cancer development (HR < 1,  < 0.05). RADIL may be a new immunotherapy target for kidney cancer post kidney transplantation.

Rap GTPase Interactor: A Potential Marker for Cancer Prognosis Following Kidney Transplantation.

Although sites for clinical or experimental islet transplantation are well established, pancreatic islet survival and function in these locations remain unsatisfactory. A possible factor that might account for this outcome is local hypoxia caused by the limited blood supply. Here, we modified a prevascularized tissue-engineered chamber (TEC) that facilitated the viability and function of the seeded islets in vivo by providing a microvascular network prior to transplantation. TECs were created, filled with Growth Factor-Matrigel™ (Matrigel™) and then implanted into the groins of mice with streptozotocin-induced diabetes. The degree of microvascularization in each TECs was analyzed by histology, real-time PCR, and Western blotting. Three hundred syngeneic islets were seeded into each chamber on days 0, 14, and 28 post-chamber implantation, and 300, 200, or 100 syngeneic islets were seeded into additional chambers on day 28 post-implantation, respectively. Furthermore, allogeneic or xenogeneic islet transplantation is a potential solution for organ shortage. The feasibility of TECs as transplantation sites for islet allografts or xenografts and treatment with anti-CD45RB and/or anti-CD40L (MR-1) was therefore explored. A highly developed microvascularized network was established in each TEC on day 28 post-implantation. Normalization of blood glucose levels in diabetic mice was negatively correlated with the duration of prevascularization and the number of seeded syngeneic islets. Combined treatment with anti-CD45RB and MR-1 resulted in long-term survival of the grafts following allotransplantation (5/5, 100%) and xenotransplantation (16/20, 80%). Flow cytometry demonstrated that the frequency of CD4+Foxp3-Treg and CD4+IL-4+-Th2 cells increased significantly after tolerogenic xenograft transplantation, while the number of CD4+IFN-γ-Th1 cells decreased. These findings demonstrate that highly developed microvascularized constructs can facilitate the survival of transplanted islets in a TECs, implying its potential application as artificial pancreas in the future.

A novel prevascularized tissue-engineered chamber as a site for allogeneic and xenogeneic islet transplantation to establish a bioartificial pancreas.

After transplantation, inflammation and tissue injury release danger signals that activate myeloid cells, driving adaptive immune responses and acute rejection. Current immunosuppressants primarily target T cells but inadequately control innate immunity. Regulatory signals controlling innate responses in transplantation remain elusive. The sialic acid-binding immunoglobulin-like lectin-E (Siglec-E, or SigE) binds sialylated ligands to suppress inflammation. In mouse heart transplants, SigE is up-regulated in graft-infiltrating myeloid cells, including dendritic cells (DCs). SigE deficiency in recipients, but not donors, accelerates acute rejection by enhancing DC activation, nuclear factor κB (NF-κB) signaling, and tumor necrosis factor-α (TNF-α) production, thereby boosting alloreactive T cell responses. Conversely, SigE overexpression on DCs reduces activation by danger signals and their T cell allostimulatory capacity. The human homologs Siglecs-7 and -9 were up-regulated in rejecting allograft biopsies, and their higher expression correlated with improved allograft survival. Thus, SigE/7/9 is a crucial inhibitory receptor controlling antigen-presenting cell activation and T cell-mediated transplant rejection, offering therapeutic potential.

The inhibitory receptor Siglec-E controls antigen-presenting cell activation and T cell-mediated transplant rejection.

Achieving immune tolerance is a key goal in organ transplantation, as it eliminates the need for long-term immunosuppression. Regulatory B cells (Bregs) present a promising strategy for inducing tolerance. Our previous findings demonstrate that the adoptive transfer of ex vivo-expanded murine splenic B regulatory cells, referred to as TLR-Bregs (TLR9/TLR4 stimulation), induces tolerance to allografts. Here, we identify that circulating T cells increase PD-1 expression following TLR-Bregs cellular therapy. To investigate whether PD-L1-PD-1 signaling is involved in tolerance induction by TLR-Bregs, we generate TLR-Bregs from wild-type (WT) or PD-L1-deficient (, KO) B6 splenocytes and assess their regulatory functions. Our findings reveal that TLR-Bregs express high levels of PD-L1 and extend graft survival via a PD-L1-dependent mechanism. Mechanistically, PD-L1 enhances the activation and survival of TLR-Bregs; PD-L1 is required for TLR-Bregs to induce PD-1 expression and an optimal inhibition of effector CD4T cells while promoting the formation of functional Foxp3CCR7CTLA4Tregs. This study highlights the foundational role of PD-L1 in inducing tolerance by ex-vivo-expanded TLR-Bregs.

PD-L1 on ex-vivo Expanded Toll-like-receptor-Bregs Prevents Allograft Rejection by Breg Viability Promotion, CD4T Effector Cell Suppression, and Tregs Induction.

Article	Year
Profiling of mRNA of interstitial fibrosis and tubular atrophy with subclinical inflammation in recipients after kidney transplantation. Aging\| PubMed ID: 31343413	2019
Rap GTPase Interactor: A Potential Marker for Cancer Prognosis Following Kidney Transplantation. Frontiers in oncology\| PubMed ID: 31448237	2019
A novel prevascularized tissue-engineered chamber as a site for allogeneic and xenogeneic islet transplantation to establish a bioartificial pancreas. PloS one\| PubMed ID: 33270650	2020
The inhibitory receptor Siglec-E controls antigen-presenting cell activation and T cell-mediated transplant rejection. Science translational medicine\| PubMed ID: 40333992	2025
PD-L1 on ex-vivo Expanded Toll-like-receptor-Bregs Prevents Allograft Rejection by Breg Viability Promotion, CD4T Effector Cell Suppression, and Tregs Induction. American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons\| PubMed ID: 40925525	2025

Minxue Liao

Biography

JoVE Journal Publications

Other Publications