Project description:CD70 is an attractive target for chimeric antigen receptor (CAR) T-cell therapy for the treatment of both solid and liquid malignancies. However, the functionality of CD70-specific CAR T-cells is modest. We optimized a CD70-specific VHH-based CAR (nanoCAR). We evaluated the nanoCARs in clinically relevant models in vitro, using co-cultures of CD70-specific nanoCAR T-cells with malignant rhabdoid tumor organoids, and in vivo using a diffuse large B-cell lymphoma (DLBCL) patient-derived xenograft (PDX) model. Whereas the nanoCAR T-cells were highly efficient in organoid co-cultures, they showed only modest efficacy in the PDX model. Fratricide was not causing this loss in efficacy but rather CD70 interaction in cis with the nanoCAR, as validated by imaging flowcytometry, induces exhaustion. Knocking out CD70 expression in nanoCAR T-cells using CRISPR/Cas9, resulted in dramatically enhanced functionality in the DLBCL PDX model. Through single-cell transcriptomics, we obtained evidence that CD70 knock out (KO) CD70-specific nanoCAR T-cells were protected from antigen-induced exhaustion. In addition, we were able to demonstrate that WT CD70-specific nanoCAR T-cells already exhibit signs of exhaustion shortly after production. Their gene signature strongly overlapped with gene signatures of exhausted CAR T-cells. On the other hand, the gene signature of KO nanoCAR T-cells overlapped with the gene signature of CAR T-cell infusion products that led to complete responses in chronic lymphatic leukemia patients. Our data show that CARs targeting endogenous T-cell antigens, negatively affect CAR T-cell functionality by inducing an exhausted state, which can be overcome by knocking out the specific target, in this case CD70.
Project description:CD70 is an attractive target for chimeric antigen receptor (CAR) T cell therapy as treatment for both solid and liquid malignancies. However, functionality of CD70-specific CAR T cells is only modest. Here, we optimized a CD70-specific VHH based CAR (nanoCAR). We evaluated the nanoCARs in clinically relevant models in vitro, using co-cultures of CD70-specific nanoCAR T cells with malignant rhabdoid tumor organoids, and in vivo by using a diffuse large B cell lymphoma (DLBCL) patient-derived xenograft (PDX) model. Whereas the nanoCAR T cells were highly efficient in organoid co-cultures, they showed only modest efficacy in the PDX model. Knocking out CD70 expression in the nanoCAR T cells resulted in dramatically enhanced functionality in the PDX model, suggesting that CD70 interaction in cis with the nanoCAR induces exhaustion. Through single-cell transcriptomics, we obtained evidence that CD70 KO CD70-specific nanoCAR T cells are protected from antigen-induced exhaustion. Our data show that CARs targeted to endogenous T cell antigens, negatively affect CAR T cell functionality by inducing an exhausted state, which can be overcome by knocking out the specific target, in this case CD70.
Project description:We used microarrays to detail the global programme gene expression of Phf8 knock out and wild type mice Different expression profile were compared between Phf8 knock out and wild type mice
Project description:The role of rpoS gene in the formation of Escherichia coli biofilms were investigated. The gene expression was compared among E. coli MG1655 wild type strain and rpoS knock-out strain in the biofilms, the planktonic exponential phase, and the planktonic stationary phase. The analysis revealed that the wild type bilfilms (WBF) showed similar pattern of gene expression with the WT planktonic stationary phase (WS), whereas the rpoS knock-out biofilms (MBF) showed similar pattern of gene expression with the wild type planktonic exponential phase (WE). Genes involved in the energy metabolism and the flagella synthesis showed higher expression in the rpoS knock-out biofilms (MBF), but not in the wild type biofilms (WBF). Moreover, genes involved in the stress responses showed higher expression in the wild type biofilms (WBF), but not in the rpoS knock-out biofilms (MBF). Keywords: cell type comparison (biofilms vs planktonic cells, wild type vs rpoS knock-out strains)
Project description:Transcriptional profiling of an HtrA proteases knock-out compared to wild type on two different time points; logarithmic growth phase and stationary growth phase
Project description:The purpose of this study was to investigate the transcriptional regulation of endothelial cells in CCM pathology. We isolated cerebellar endothelial cells from healthy (wild-type) mice and from mice with an inducible endothelial-specific knock-out of the Ccm3 gene (Ccm3 knock-out). We prepared RNA libraries and sequenced the samples on a HiSeq2500 sequencing system with v4 chemistry from Illumina. We then performed a differential gene expression analysis to identify genes that play a role in CCM pathology.