Biology subjects

Kabelitz, D.

Publications and source records attributed to Kabelitz, D..

3 recordsLinked to original sources

bioRxiv2025

Blinatumomab-driven T-cell activation in αβ and γδ T-cell subsets: Insights from in vitro assays

Blinatumomab (BLN) is a bispecific T-cell engager that has revolutionized the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), significantly improving outcomes in both adults and children. By simultaneously binding to CD19 on B cells and CD3 on T cells, BLN triggers target cell-dependent T-cell activation, resulting in the cytolysis of CD19+ BCP-ALL cells. Despite the remarkable clinical advancements achieved with BLN, the immunological mechanisms underlying treatment response or failure remain poorly characterized. {gamma}{delta} T cells are attractive candidates for adoptive T-cell therapy due to potent cytotoxicity, capacity to present antigens, broad lysis of different tumor entities, and low alloreactivity. Because {gamma}{delta} T cells can also be redirected by BLN, we systematically studied BLN-driven effector functions of conventional {beta} and unconventional {gamma}{delta} T cells. We evaluated cytotoxicity and cytokine/effector release in freshly isolated and in vitro-expanded {beta} and {gamma}{delta} T cells from healthy adults against CD19 BCP-ALL lines (NALM-6, HAL-01), and profiled dynamic phenotypic alterations by multiparametric flow cytometry. CD19 targets were consistently reduced in the presence of BLN. Freshly isolated {beta}, especially CD8, displayed superior BLN-mediated cytotoxicity as compared to {gamma}{delta} T cells, with donor-dependent variability in {gamma}{delta} killing. Notably, zoledronate-expanded V{gamma}9V{delta}2 {gamma}{delta} T-cell lines achieved cytotoxicity comparable to PHA-expanded {beta} cells. However, {gamma}{delta} T-cell-killing benefited from higher BLN concentration when challenged with high tumor load. BLN induced CD3 down-modulation in {beta} T cells but not in {gamma}{delta} T cells, alongside higher soluble Fas ligand in {beta} cultures, consistent with stronger early activation, preceding activation-induced cell death. {gamma}{delta} T cells showed no such changes, suggesting reduced susceptibility to activation-induced cell death. Single-cell RNA and flow analyses corroborated these findings, showing robust activation/exhaustion programs in {beta} T cells and a stable effector-memory state with low checkpoint expression in {gamma}{delta} T cells. Together, these data reveal subset-specific BLN responses and support expanded V{gamma}9V{delta}2 {gamma}{delta} T cells as a rational adoptive partner to BLN -- particularly in settings of favorable antigen density/low tumor burden -- providing complementary cytotoxicity with potentially reduced inflammatory liability. These findings provide a framework for combining {gamma}{delta} T-cell-based therapies in BLN-treated patients for improving BLN efficacy in BCP-ALL patients.

immunology↗

bioRxiv2023

γδ T cell-mediated cytotoxicity against patient-derived healthy and cancer cervical organoids

Cervical cancer is a leading cause of death among women globally, primarily driven by high-risk papillomaviruses. However, the effectiveness of chemotherapy is limited, underscoring the potential of personalized immunotherapies. Patient-derived organoids, which possess cellular heterogeneity, proper epithelial architecture and functionality, and long-term propagation capabilities offer a promising platform for developing viable strategies. In addition to {beta} T cells and natural killer (NK) cells, {gamma}{delta} T cells represent a cell population with significant therapeutic potential against both hematologic and solid tumours. To evaluate the efficacy of {gamma}{delta} T cells in cervical cancer treatment, we generated patient-derived healthy and cancer ectocervical organoids. Furthermore, we examined transformed healthy organoids, expressing HPV16 oncogenes E6 and E7. We analysed the effector function of in vitro expanded {gamma}{delta} T cells upon co-culture with organoids. Our findings demonstrated that healthy cervical organoids were less susceptible to {gamma}{delta} T cell-mediated cytotoxicity compared to HPV-transformed organoids and cancerous organoids. To identify the underlying pathways involved in this observed cytotoxicity, we performed bulk-RNA sequencing on the organoid lines, revealing differences in DNA-damage and cell cycle checkpoint pathways, as well as transcription of potential {gamma}{delta} T cell ligands. We validated these results using immunoblotting and flow cytometry. We also demonstrated the involvement of BTN3A1 and BTN2A1, crucial molecules for {gamma}{delta} T cell activation, as well as differential expression of PDL1/CD274 in cancer, E6/E7+ and healthy organoids. Interestingly, we observed a significant reduction in cytotoxicity upon blocking MSH2, a protein involved in DNA mismatch-repair. In summary, we established a co-culture system of {gamma}{delta} T cells with cervical cancer organoids, providing a novel in vitro model to optimize innovative patient-specific immunotherapies for cervical cancer.

immunology↗

bioRxiv2018

Predicting humoral alloimmunity from differences in donor-recipient HLA surface electrostatic potential

In transplantation, development of humoral alloimmunity against donor HLA is a major cause of organ transplant failure but our ability to assess the immunological risk associated with a potential donor-recipient HLA combination is limited. We hypothesised that the capacity of donor HLA to induce a specific alloantibody response depends on their structural and physicochemical dissimilarity compared to recipient HLA. To test this hypothesis, we first developed a novel computational scoring system that enables quantitative assessment of surface electrostatic potential differences between donor and recipient HLA molecules at the tertiary structure level (electrostatic mismatch score-three dimensional; EMS-3D). We then examined humoral alloimmune responses in healthy females subjected to a standardised injection of donor lymphocytes from their male partner. This analysis showed a strong association between the EMS-3D of donor HLA and donor-specific alloantibody development; this relationship was strongest for HLA-DQ alloantigens. In the clinical transplantation setting, the immunogenic potential of HLA-DRB1 and -DQ mismatches expressed on donor kidneys, as assessed by their EMS-3D, was an independent predictor of development of donor-specific alloantibody after graft failure. Collectively, these findings demonstrate the translational potential of our approach to improve immunological risk assessment and to decrease the burden of humoral alloimmunity in organ transplantation.

immunology↗