Biology subjects

Wendering, D. J.

Publications and source records attributed to Wendering, D. J..

2 recordsLinked to original sources

bioRxiv2025

Clinical development of gene edited tacrolimus-resistant Treg (FKBP12KO-Treg) to enable simultaneous immunosuppression and support of immune regulation

Background: Unwanted immune responses play a central role in the pathogenesis of solid organ allograft rejection. These are managed by life-long immunosuppression with considerable burden for the patient and society. Adoptive therapy with regulatory T-cells (Treg) is a promising approach to restore sustainable immune balance and avoid long-term adverse effects of immunosuppression. While Treg effectively inhibit activation of unwanted immune responses, they are less effective in controlling pre-existing/activated memory effector T-cells (Teff). Thus, co-administration of Treg with immunosuppressants is required to achieve a sustainable organ acceptance. Calcineurin inhibitors (CNI) are powerful in controlling de novo generated and preformed Teff. However, CNI also dampen Treg immunoregulatory function. Thus, we hypothesize improved results of adoptive Treg therapy in immunosuppressed patients applying tacrolimus-resistant Treg. Methods: While retaining CNI modulation of Teff with tacrolimus, we knocked-out FKBP12 in Treg (FKBP12KO-Treg) by gene-editing using ribonucleoprotein-based CRISPR/Cas9 technology to generate tacrolimus-resistant Treg and characterised them using flow cytometry, functional assays and in-depth phenotyping. Results: This detailed in vitro analysis showed FKBP12KO-Treg were comparable to non-gene edited Treg and impervious to tacrolimus while maintaining immunoregulatory function and sensitivity to alternative CNIs raising no safety concerns. Furthermore, we aligned our methodology to achieve GMP compliance laying the basis for a manufacturing license in preparation of a clinical trial. Conclusion: Based on the presented preclinical dataset implying safety and efficacy of FKBP12KO-Treg, we are now seeking to undertake a proof-of-concept clinical trial to evaluate the co-administrationof FKBP12KO-Treg and tacrolimus to enhance the management of living donor kidney transplant recipients.

immunology↗

bioRxiv2018

High prevalence of S. pyogenes Cas9-specific T cell sensitization within the adult human population - A balanced effector/regulatory T cell response

Summary ParagraphThe field of gene therapy has been galvanized by the discovery of the highly efficient and adaptable site-specific nuclease system CRISPR/Cas9 from bacteria.1,2 Immunity against therapeutic gene vectors or gene-modifying cargo nullifies the effect of a possible curative treatment and may pose significant safety issues.3-5 Immunocompetent mice treated with CRISPR/Cas9-encoding vectors exhibit humoral and cellular immune responses against the Cas9 protein, that impact the efficacy of treatment and can cause tissue damage.5,6 Most applications aim to temporarily express the Cas9 nuclease in or deliver the protein directly into the target cell. Thus, a putative humoral antibody response may be negligible.5 However, intracellular protein degradation processes lead to peptide presentation of Cas9 fragments on the cellular surface of gene-edited cells that may be recognized by T cells. While a primary T cell response could be prevented or delayed, a pre-existing memory would have major impact. Here, we show the presence of a ubiquitous memory/effector T cell response directed towards the most popular Cas9 homolog from Streptococcus pyogenes (SpCas9) within healthy human subjects. We have characterized SpCas9-reactive memory/effector T cells (TEFF) within the CD4/CD8 compartments for multi-effector potency and lineage determination. Intriguingly, SpCas9-specific regulatory T cells (TREG) profoundly contribute to the pre-existing SpCas9-directed T cell immunity. The frequency of SpCas9-reactive TREG cells inversely correlates with the magnitude of the respective TEFF response. SpCas9-specific TREG may be harnessed to ensure the success of SpCas9-mediated gene therapy by combating undesired TEFF response in vivo. Furthermore, the equilibrium of Cas9-specific TEFF and TREG cells may have greater importance in Streptococcus pyogenes-associated diseases. Our results shed light on the T cell mediated immunity towards the much-praised gene scissor SpCas9 and offer a possible solution to overcome the problem of pre-existing immunity.

immunology↗