establishment-rat-model-acute-antibody-mediated-rejection-kidney

Establishment of Rat Model of Acute Antibody-Mediated Rejection in Kidney Transplantation

Acute antibody-mediated rejection (AAMR) remains a major obstacle to long-term graft survival in kidney transplantation. The pathophysiology of AAMR is ...

establishment-mouse-model-renal-fibrosis-via-unilateral-ischemia

Establishment of A Mouse Model of Renal Fibrosis <em>via</em> Unilateral Ischemia-Reperfusion Injury And Delayed Contralateral Nephrectomy

Renal ischemia-reperfusion injury (IRI) contributes to acute kidney injury (AKI) and is a major driver of progression to chronic kidney disease (CKD). A ...

The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital

Acute rejection is the main contributor to early allograft failure. Current immunosuppressive regimens have shortcomings, such as toxicity and minimal inhibitory effects on B cells. Hence, developing novel, effective, and selective anti-acute rejection drugs is crucial. Therefore, this study aimed to investigate the inhibitory effect of ritlecitinib (PF-06651600), a new janus kinase 3 inhibitor, on T and B cells, as well its preventive effects on acute allograft rejection. A murine cardiac transplantation model coupled with cell culture- and immunohistochemistry-based techniques was used. In vitro assays demonstrated that ritlecitinib inhibits naïve CD4 T cell differentiation into T helper (Th)1 and Th17 cells, reduces relative inflammatory cytokines, and suppresses CD4 and CD8 T cell proliferation. Furthermore, ritlecitinib inhibited B cell activation and differentiation and antibody production. In vivo experiments revealed that ritlecitinib significantly prolongs allograft survival, decreases serum donor-specific antibody immunoglobulin G levels, alleviats allograft damage, and reduces C4d deposition and T, B, and plasma cell infiltration in allografts. Moreover, B and plasma cell percentages and counts were significantly decreased in recipient spleen, lymph nodes, bone marrow, and blood. Overall, ritlecitinib prevented acute rejection in cardiac transplantation by inhibiting T and B cells, suggesting its potential as a novel clinical immunosuppressant.

Novel janus kinase 3 inhibitor ritlecitinib suppresses T and B cell responses to prevent acute cardiac allograft rejection in mice.

Cardiac transplantation is the preferred treatment option for patients with chronic heart failure. However, acute rejection remains as a the significant challenge that leads to cardiac allograft dysfunction, resulting from immune system activation and reactive oxygen species (ROS) production by inflammatory cells. Current immunosuppressive regimens have limitations, such as systemic administration, toxicity, and inefficient inhibition of B cells, macrophages, and natural killer (NK) cells. Targeted immunosuppressant delivery via nanomaterials is a promising approach for sustained release within allografts, significantly enhancing drug efficiency. Manganese dioxide (MnO) possesses the characteristics of chemotaxis towards inflammatory sites, scavenging ROS, and facilitating drug transport. In this study, tacrolimus (FK506)-loaded MnO nanoparticles (NPs) are synthesized via in-situ polymerization, using polydopamine (PDA) as an intermediate. The resulting FK506@MnO/PDA NPs exhibit excellent safety and cytocompatibility. This targeted delivery system significantly increases FK506 accumulation in murine cardiac allografts, effectively mitigating acute rejection and prolonging allograft survival. Furthermore, the mechanism by which FK506@MnO/PDA NPs alleviate acute rejection is investigated, validating that FK506 release inhibits T-cell activation while modulating the inflammatory environment by reducing oxidative stress and scavenging ROS. Fluorescence imaging demonstrates that FK506@MnO/PDA NPs exhibit prolonged retention and more pronounced accumulation in cardiac allografts compared with free FK506. This study presents a novel strategy for immunosuppressive therapy following cardiac transplantation, potentially improving allograft prognosis.

Targeted tacrolimus delivery via manganese dioxide nanoparticles for mitigating acute allograft rejection in murine cardiac transplantation.

Follicular helper T (Tfh), B and regulatory T (Treg) cells are involved in the pathogenesis of chronic rejection (CR) after transplantation. Dihydroartemisinin (DHA) is an antimalarial drug with anti-inflammatory activity; however, the effects and mechanisms of DHA on Tfh, B and Treg cells have not been comprehensively elucidated. The aim of this study was to investigate the effect of DHA on Tfh, B and Treg cells and its preventive effect on CR. In vitro assays demonstrated that DHA not only blocks the induction of Tfh cells and alleviates their supportive effect on B cell differentiation but also directly suppresses B cell activation, differentiation and antibody production. Additionally, DHA promotes the induction of Treg cells and enhances their stability in an inflammatory environment. In vivo studies showed that DHA effectively alleviated CR by suppressing neointimal hyperplasia, myocardial injury and interstitial fibrosis and reducing inflammatory cell infiltration and C4d deposition in allografts. Moreover, DHA decreased the levels of Tfh, germinal centre Tfh, B, germinal centre B, IgG-producing and plasma cells in recipients but increased Treg cell levels in recipients and allografts. Mechanistically, we confirmed that DHA inhibits Tfh cells by blocking IL-2-inducible T cell kinase signalling, suppresses B cells by blocking Bruton's tyrosine kinase signalling, and enhances Treg cells by blocking mTOR signalling while promoting STAT5 signalling. In conclusion, our results verified that DHA inhibits Tfh and B cells and enhances Treg cells to attenuate CR in mice, highlighting its potential applicability in the development of robust treatment options.

ArticleTotal : 2	Year
Publication title	2026
Publication title	2026

Article	Year
Novel janus kinase 3 inhibitor ritlecitinib suppresses T and B cell responses to prevent acute cardiac allograft rejection in mice. Clinical immunology (Orlando, Fla.)\| PubMed ID: 39954912	2025
Targeted tacrolimus delivery via manganese dioxide nanoparticles for mitigating acute allograft rejection in murine cardiac transplantation. Biomaterials\| PubMed ID: 41056839	2026
Dihydroartemisinin Alleviates Chronic Allograft Rejection by Inhibiting Tfh and B Cells While Promoting Treg Cells in Murine Cardiac Transplantation. Immunology\| PubMed ID: 41437677	2025

Tao Liao

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