Biology subjects
Publications and source records attributed to Simonetta, F..
Antigen density critically influences CAR T-cell efficacy. We show that ibrutinib induces CD19 upregulation in B-cell lymphoma models, enhancing CAR T-cell cytotoxicity. Pharmacologic modulation of target antigen expression represents a promising strategy to overcome resistance.
Introducing Brutons tyrosine kinase (BTK) inhibitors has significantly improved outcomes for patients with B-cell malignancies and autoimmune disorders. However, resistance, either primary or acquired, remains a major clinical challenge. To better understand the underlying resistance mechanisms to BTK inhibitors, we established an ibrutinib-resistant model from a patient-derived splenic marginal zone lymphoma (MZL) cell line (VL51) through prolonged drug exposure. Resistant cells exhibited a 15-fold increase in ibrutinibs IC50, along with distinct morphological changes, mitochondrial activation, and cross-resistance to covalent, non-covalent BTK inhibitors and BTK degraders. Integrated transcriptomic, epigenomic, and proteomic analyses identified overexpression and secretion of IL-16 as a key feature of resistance, driven by chromatin remodeling and activation of the FLI1 transcription factor. IL-16 conferred ibrutinib resistance via CD9-mediated activation of the NF-{kappa}B and AKT signaling pathways and was found to be elevated in the serum of ibrutinib-refractory CLL patients. Functional studies showed that targeting the IL-16/CD9 axis using neutralizing antibodies or CD9-binding peptides restored sensitivity to BTK inhibitors and R-CHOP chemotherapy in MZL, mantle cell lymphoma, and diffuse large B-cell lymphoma models. These findings reveal a novel, targetable resistance mechanism with potential therapeutic implications for overcoming BTK inhibitor resistance in B-cell lymphomas.
B cell receptor (BCR) signaling plays a central role in the pathogenesis of B cell lymphomas, making it a crucial therapeutic target. The advent of BCR-targeted inhibitors, particularly those directed at PI3K and BTK, has revolutionized treatment for B cell non-Hodgkin lymphoma (B-NHL). However, therapeutic resistance remains a significant clinical challenge. Increasing evidence suggests that the tumor microenvironment (TME), particularly the bone marrow (BM) microenvironment, is crucial in driving cancer progression and therapeutic resistance. The BM microenvironment provides a specialized niche where lymphoma cells can evade therapy through interactions with stromal cells and extracellular matrix (ECM) components. Bone marrow stromal cells (BMSCs) contribute significantly to this resistance. In this study, we developed an in vitro 3D model to better understand B cell lymphoma biology and drug resistance mechanisms. We co-cultured lymphoma cell lines with primary BMSCs in a 3D fibrin gel matrix using a high-throughput and automated system. Our results revealed that BMSCs modulate lymphoma cell growth and reduce their sensitivity to the PI3K inhibitor copanlisib and the BTK inhibitor ibrutinib. Furthermore, this model allowed us to identify IGFBP-3, Serpin E1, and PTX-3 as potential mediators of therapeutic resistance. These findings underscore the value of using 3D co-culture models in preclinical settings to more accurately study drug resistance, as they more closely simulate the BM microenvironments complexity than traditional 2D models, thus improving the predictive value of drug testing in B cell lymphomas. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/632958v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@72bc6aorg.highwire.dtl.DTLVardef@afdda2org.highwire.dtl.DTLVardef@1fff494org.highwire.dtl.DTLVardef@11252cf_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOVisual AbstractC_FLOATNO C_FIG
Targeted eradication of transformed or otherwise dysregulated cells using monoclonal antibodies (mAb), antibody-drug conjugates (ADC), T cell engagers (TCE) or chimeric antigen receptor (CAR) cells is very effective for haematologic diseases. Unlike the breakthrough progress achieved for B cell malignancies, there is a pressing need to find suitable antigens for immunotherapy of myeloid malignancies. CD123, the interleukin-3 (IL-3) receptor alpha-chain, is highly expressed in various haematological malignancies, including acute myeloid leukaemia (AML) and blastic plasmacytoid dendritic cell neoplasm (BPDCN). However, shared expression of CD123 on healthy haematopoietic stem and progenitor cells (HSPCs) bears the risk for extensive myelotoxicity upon targeted depletion. Here, we demonstrate that rationally designed, epitope-engineered HSPCs were completely shielded from CD123-targeted immunotherapy but remained fully functional while CD123-deficient HSPCs displayed a competitive disadvantage. Thus, molecularly shielded HSPCs could allow tumor-selective targeted immunotherapy and in parallel enable rebuilding a fully functional haematopoietic system. We envision that this approach is broadly applicable to many targets and cells, could render hitherto undruggable targets accessible to immunotherapy and will allow continued posttransplant immunotherapy, for instance to treat minimal residual disease (MRD) or be used as a salvage therapy. Since the function of the engineered targets is preserved, multiplexed molecular shielding could also enable targeted combination immunotherapies to address tumor heterogeneity. More generally, epitope shielding will be applicable for replacement of other cell types including the many immune cells which are currently being considered for engineered cellular therapies.
Invariant natural killer T (iNKT) cells are a subset of heterogenous T-cells with potent cytotoxic and immunomodulatory properties. During thymic development, murine iNKT cells go through different maturation stages and differentiate into distinct sublineages, namely iNKT1, iNKT2, and iNKT17 cells. To define maturation stages and to assess sublineage commitment of human iNKT cells during thymic development, we performed single-cell RNA sequencing analysis on human thymic iNKT cells. We show that these iNKT cells displayed heterogeneity and unsupervised analysis identified two clusters: one with an immature profile with high expression of genes that are important for iNKT cell development and enriched in cells expressing an iNKT2 signature, whereas a second cluster displayed a mature, terminally differentiated profile resembling murine iNKT1 cells. Trajectory analysis suggested an ontological relationship between the two clusters. Our work provides the first single cell transcriptomic analysis of thymic human iNKT cells offering new insights into their developmental process in humans.
CD4+FOXP3+ regulatory T cells have demonstrated efficacy in graft-versus-host disease (GvHD) prevention and treatment. Preclinical and clinical studies indicate that Treg are able to protect from GvHD without interfering with the graft-versus-tumor (GvT) effect of hematopoietic cell transplantation (HCT), although the underlying molecular mechanisms are largely unknown. To elucidate Treg suppressive function during in vivo suppression of acute GvHD, we performed paired T cell receptor (TCR, TCR{beta} genes) repertoire sequencing and RNA sequencing analysis on conventional T cells (Tcon) and Treg before and after transplantation in an MHC major-mismatch mouse model of HCT. We show that both Treg and Tcon underwent clonal restriction and that Treg did not interfere with the activation of alloreactive Tcon clones and the breadth of their TCR repertoire, however, markedly suppressed their expansion. Transcriptomic analysis revealed that Treg predominantly affected the transcriptome of CD4 Tcon and to a lesser extent of CD8 Tcon, modulating the transcription of genes encoding pro- and anti-inflammatory molecules as well as enzymes involved in metabolic processes, inducing a switch from glycolysis to oxidative phosphorylation. Finally, Treg did not interfere with the induction of gene sets involved in the GvT effect. Our results shed light into the mechanisms of acute GvHD suppression by Treg and will support the clinical translation of this immunoregulatory approach. Key Points- Regulatory T cells modulate conventional T cells transcriptome during GvHD suppression by affecting several, non-redundant pathways. - Regulatory T cells undergo activation and clonal expansion during GvHD suppression.
Longitudinal multimodal imaging presents unique opportunities for noninvasive surveillance and prediction of treatment response to cancer immunotherapy. In this work we first designed a novel granzyme B activated self-assembly small molecule, G-SNAT, for quantitative assessment of cytotoxic T lymphocyte mediated cancer cell killing in vivo. In lymphoma tumor bearing mice, the retention of cyanine 5 labeled G-SNAT-Cy5 was shown to be highly correlated to CAR T-cell mediated granzyme B release and tumor eradication. In colorectal tumor-bearing transgenic mice, expressing firefly luciferase in hematopoietic cells, and which received combination treatment of anti-PD-1 and anti-CTLA-4, longitudinal bioluminescence and fluorescence imaging revealed the dynamics of immune cell expansion, trafficking, tumor infiltration, and cytotoxic activity which predicted therapeutic outcome before tumor shrinkage was evident. These results support further development of G-SNAT for imaging early immune response to checkpoint blockade and CAR T-cell therapy in patients and highlight the utility of multimodality imaging for improved mechanistic insights into cancer immunotherapy.
The development of allogeneic chimeric antigen receptor (CAR) T cell therapies for off-the-shelf use is a major goal yet faces two main immunological challenges, namely the risk of graft-versus-host-disease (GvHD) induction by the transferred cells and the rejection by the host immune system limiting their persistence. We demonstrate that allogeneic CAR-engineered invariant natural killer T (iNKT) cells, a cell population without GvHD-induction potential that displays immunomodulatory properties, exerted potent direct and indirect antitumor activity in murine models of B-cell lymphoma when administered across major MHC-barriers. In addition to their known direct cytotoxic effect, allogeneic CAR iNKT cells induced tumor-specific antitumor immunity through host CD8 T cell cross-priming, resulting in a potent antitumor effect lasting longer than the physical persistence of the allogeneic cells. The utilization of off-the-shelf allogeneic CAR iNKT cells could meet significant unmet needs in the clinic.