Biology subjects

Jeanneau, C.

Publications and source records attributed to Jeanneau, C..

3 recordsLinked to original sources

bioRxiv2024

Enhanced anti-tumor activity by Zinc Finger Repressor-driven epigenetic silencing of immune checkpoints and TGFBR2 in CAR-T cells and TILs

CAR-T therapies have shown remarkable success in treating hematological malignancies. However, effectiveness against solid tumors remains limited due to the immunosuppressive tumor microenvironment (TME), such as TGF-{beta} signaling and upregulated immune checkpoints (ICs). Furthermore, identifying universal, tumor-specific targets for CAR-T cells in solid tumors is challenging, but using reinvigorated, immunosuppressive-resistant tumor-infiltrating lymphocytes (TILs) could be a promising alternative approach. Unlike nucleases, which may induce genotoxic DNA double-strand breaks, multiplexed Zinc Finger Repressors (ZFR) offer a safer alternative for knocking out TME-related immunosuppressive factors. We epigenetically repressed PD-1 expression both in CAR-T cells and TILs from colorectal liver metastases. PD-1 repression did not affect T cell viability, proliferation, or functionality. In a murine B cell lymphoma model, PD-1-repressed CD19-CAR-T cells exhibited enhanced anti-tumor activity and improved survival. Notably, PD-1 repression alone did not increase cytotoxicity against a PD-L1-positive colorectal cell line in vitro. To further increase anti-tumor potency in this context, ZFR-expressing lentiviral vectors targeting PD-1 and other ICs (LAG-3, TIM-3, TIGIT) or TGFBR2 were developed, improving significantly the cytotoxic activity in TILs. This strategy highlights the potential to enhance tumor-reactive T cells and improve anti-cancer immunotherapies by epigenetically repressing immunosuppressive factors in the TME using multiplexed ZFRs.

cancer biology↗

bioRxiv2024

Epigenetic control of multiple genes with a single lentiviral vector encoding transcriptional repressors fused to compact zinc finger arrays

Gene silencing without gene editing holds great potential for the development of safe therapeutic applications. Here, we describe a novel strategy to concomitantly repress multiple genes using zinc finger proteins fused to Kruppel-Associated Box repression domains (ZF-Rs). This was achieved via the optimization of a lentiviral system tailored for the delivery of ZF-Rs in hematopoietic cells. We showed that an optimal design of the lentiviral backbone is crucial to multiplex up to three ZF-Rs or two ZF-Rs and a chimeric antigen receptor. ZF-R expression had no impact on the integrity and functionality of transduced cells. Furthermore, gene repression in ZF-R-expressing T cells was highly efficient in vitro and in vivo during the entire monitoring period (up to ten weeks), and it was accompanied by epigenetic remodeling events. Finally, we described an approach to improve ZF-R specificity to illustrate the path towards the generation of ZF-Rs with a safe clinical profile. In conclusion, we successfully developed an epigenetic-based cell engineering approach for concomitant modulation of multiple gene expressions that bypass the risks associated with DNA editing.

bioengineering↗

bioRxiv2018

Elucidating the roles of Alzheimer disease-associated proteases and the signal-peptide peptidase-like 3 (SPPL3) in the shedding of glycosyltransferases

The Golgi resident glycosyltransferases (GTs) are membrane-bound glycoproteins but are frequently found as soluble proteins in biological fluids where their function remains largely unknown. Previous studies have established that the release of these proteins involved Alzheimer disease-associated proteases such as {beta}-secretases (BACE1 and BACE2) and the intramembrane-cleaving aspartyl proteases Presenilins 1 and 2. Recent studies have involved another intramembrane-cleaving enzyme, the signal peptide peptidese-like-3 (SPPL3). Except for the latter, the two former studies mostly addressed particular cases of GTs, namely ST6Gal-I (BACEs) or GnT-V (Presenilins). Therefore the question still remains as which of these secretases is truly responsible for the cleavage and secretion of GTs. We herein combined the 3 proteases in a single study with respect to their abilities to release 3 families of GTs encompassing three N-acetylglucosaminyltransferases, two fucosyltransferases and two sialyltransferases. Green fluorescent protein (gfp)-fused versions of these GTs were virally transduced in mouse embryonic fibroblasts devoid of BACEs, Presenilins or SPPL3. We found that neither BACE nor Presenilins are involved in the shedding of these glycosyltransferases, while SPPL3 was involved in the cleavage and release of some but not all GTs. Notably, the {gamma}- secretase inhibitor DFK-167 was the only molecule capable of significantly decreasing glycosyltransferase secretion, suggesting the involvement of {gamma}-secretase(s), yet different from Presenilins but comprising SPPL3 among other proteases still to be identified. Using confocal microscopy, we show that SPPL3 selectivity towards GTs relays not only on sequence specificity but also depends on how GTs distribute in the cell with respect SPPL3 during their cycling within and outside the Golgi.

biochemistry↗