Biology subjects

Bonifacius, A.

Publications and source records attributed to Bonifacius, A..

3 recordsLinked to original sources

bioRxiv2024

ENTPD3-specific CAR Regulatory T cells for Local Immune Control in T1D

Despite advances in Type 1 Diabetes (T1D) management such as hybrid closed loop systems, patients still face significant morbidity, reduced life expectancy, and impaired glucose regulation compared to healthy individuals or those with pancreas transplants. Here we developed beta cell-specific Chimeric Antigen Receptors (CAR) targeting the antigen ectonucleoside triphosphate diphosphohydrolase 3 (ENTPD3) using a novel cell-based phage display methodology. ENTPD3 is highly expressed on beta cells of both early and progressed T1D patients. ENTPD3 CAR regulatory T cells (Tregs) homed, expanded and persisted in pancreatic islets in a T1D mouse model (NOD) and completely prevented disease progression. Human ENTPD3 CAR Tregs displayed a stable regulatory phenotype, strong activation, and suppression. Importantly, ENTPD3 CAR T cells recognised and were fully activated by human islets. This approach holds great promise as a durable treatment option for patients with prediabetes, new-onset diabetes, or those undergoing beta cell replacement therapy.

immunology↗

bioRxiv2023

DNA methylation profiling identifies TBKBP1 as potent amplifier of cytotoxic activity in CMV-specific human CD8+ T cells

Epigenetic mechanisms stabilize gene expression patterns during CD8+ T cell differentiation. However, although adoptive transfer of virus-specific T cells is clinically applied to reduce the risk of virus infection or reactivation in immunocompromised individuals, the DNA methylation pattern of virus-specific CD8+ T cells is largely unknown. Hence, we here performed whole-genome bisulfite sequencing of cytomegalovirus-specific human CD8+ T cells and found that they display a unique DNA methylation pattern consisting of 79 differentially methylated regions when compared to bulk memory CD8+ T cells. Among them was TBKBP1, coding for TBK-binding protein 1 that can interact with TANK-binding kinase 1 (TBK1) and mediate pro-inflammatory responses in innate immune cells downstream of intracellular virus sensing. Since TBKBP1 has not yet been reported in T cells, we aimed to unravel its role in virus-specific CD8+ T cells. TBKBP1 demethylation in terminal effector CD8+ T cells correlated with TBKBP1 expression and was stable upon long-term in vitro culture. TBKBP1 overexpression resulted in enhanced TBK1 phosphorylation upon stimulation of CD8+ T cells and significantly improved their virus neutralization capacity. Collectively, our data demonstrate that TBKBP1 modulates virus-specific CD8+ T cell responses and could be exploited as therapeutic target to improve adoptive T cell therapies.

immunology↗

bioRxiv2023

Depletion of alloreactive B cells by chimeric alloantigen receptor T cells with drug resistance to prevent antibody-mediated rejection in solid organ transplantation

In the present study, we developed a novel cell therapy approach to selectively combat antibody-mediated rejection (AMR), a major and unresolved complication after solid organ transplantation (SOT) caused by donor-HLA-specific, alloreactive B cells. Current treatment options including B-cell depletion protocols are inefficient and result in complete loss of humoral immunity. To selectively eliminate alloreactive B cells characterized by corresponding anti-donor-HLA B-cell receptors (BCRs), we engineered T cells with a novel chimeric receptor comprising a truncated HLA molecule fused to intracellular 4-1BB/CD3{xi} signaling domains to generate T cells overcoming rejection by antibodies (CORA-Ts). As proof-of-concept, CORA receptors based on HLA-A*02 were shown to bind anti-HLA-A*02 antibodies from the serum of kidney transplant recipients, indicating their suitability to also target the respective membrane-bound anti-HLA-A*02 BCRs on alloreactive B cells. In co-cultures with B-cell lines expressing and releasing anti-HLA-A*02 antibodies, CORA-Ts were specifically activated, released pro-inflammatory cytokines (e.g. IFN-{gamma}, granzyme B), and exhibited strong cytotoxicity resulting in an effective reduction of anti-HLA-A*02 antibody release. A modification of the HLA-A*02 3-domain within the CORA receptor effectively abrogated T-cell sensitization. Additionally, using CRISPR/Cas9-mediated knockout of a selected binding protein, CORA-Ts were able to resist immunosuppressive treatment to ensure high efficiency in transplant patients. Our results demonstrate that CORA-Ts are able to specifically recognize and eliminate alloreactive B cells, and thus selectively prevent formation of anti-HLA antibodies even under immunosuppressive conditions. This suggests CORA-Ts as potent novel approach to specifically combat AMR and improve long-term graft survival in SOT patients while preserving their overall B-cell immunity.

immunology↗