Making anti-tumor T lymphocytes resistant to negative signals

Réjean Lapointe, Christopher Rudd, Rénald Gilbert, Simon Turcotte

We can use the immune system, the system that protects us from germs, to fight cancer. Cancer patients can be treated with immune cell therapy by taking the anti-cancer immune cells that are often concentrated within the tumor itself, expanding them greatly in our laboratories at numbers approximating billions, and transferring them back to patients. This approach is especially effective in malignant skin cancers (melanoma), but improvements are needed. One challenge in this treatment is that despite the large number of anti-cancer immune cells transferred, once migrated within the tumor, they will encounter inhibitory signals that neutralize their anti-tumor effectiveness. In this project, we propose to make anti-cancer immune cells resistant to these inhibitory signals. We will condition the anti-cancer immune cells with chemical compounds, or by genetic modification, in order to block the action of the negative signals that will be encountered in the tumor. Since we are starting a cell therapy program this year based on the use of anti-cancer immune cells in patients at CHUM and CETC/HMR, we will be able to transfer these new approaches into our clinical trial program.

Fecal microbiota transplantation to people living With HIV With a Iow CD4 count

Jean-Pierre Routy, André Marette, Bertrand Routy

The intestine hosts billions of different microbes that help with digestion and prevent infections. Most people living with HIV (PLWH) with low CD4 T cells have dysbalanced gut microbes, which contribute to inflammation and to increased risk of developing non-AIDS comorbidities like cardiovascular diseases, fatty liver and cancers. Fecal microbiota transplantation (FM T) by giving stools from selected healthy donors, was shown to modify the gut microbiota of recipient and treat colitis due to Clostridium difficile. Moreover, FMT reduced inflammation in people with inflammatory bowel diseases Crohn's and this procedure was safe and well tolerated. We propose to reduce inflammation of PLWH with a low CD4 count by giving sealed oral capsules filled with selected donor stools. 20 PLWH taking anti-HIV drugs will be recruited. After a short antibiotic treatment to provide space for the new microbes to be transplanted, 10 participants will be assigned randomly to take FMT capsules, and 10 will be invited randomly to take empty (placebo) capsules as a control group. Inflammation will be monitored in the blood and stools will be collected before and after FMT to assess variations in gut microbes. For those who choose to participate in a sub study, gut biopsies will be obtained by colonoscopy before and after FMT or placebo.

Biofabrication and tissue engineering approaches for enhanced ligament reconstruction.

Derek Rosenzweig, Julie Fradette, Sophie Lerouge, Paul Martineau, Showan Nazhat

Anterior cruciate ligament (ACL) injuries are common, leading to reduced mobility where surgical reconstruction is standard care. However, reconstructive surgery is costly and is linked to early onset osteoarthritis associated with irregular healing, loss of mechanical function or abnormal knee biomechanics. There is therefore a clinical need for improved repair strategies to enhance patient outcomes. The overall goal of this proposal is to combine adipose-derived stromal/stem cells (ASCs) with mechanically competent scaffolds for ligament repair applications. ASCs are attractive due to their multipotency, yet not much evidence exists for ligament repair. Two types of scaffolds will be prepared: Flexible thermoplastic 3D printed scaffolds coated with cell-seeded hydrogels (scaffold A) and bioprinted aligned scaffolds consisting of cell-seeded chitosan/alginate bioink (scaffold B). ASC viability and ligament matrix deposition will be assessed in vitro and compared to primary ACL cell controls (Obj1). Both scaffold types will be matured in a bioreactor under physiological mechanical strain and viability, mechanical properties and ligament matrix deposition will be assessed (Obj2). Finally, matured scaffolds will be implanted subcutaneously in a rat model and biocompatibility, immune reactivity and potential tissue generation will be determined (Obj3). These data may suggest novel roles for ASCs in tissue engineering ACL substitutes.

Impact of corneal exosomes on the wound healing characteristics of the human tissue engineered cornea

Sylvain Guérin, Sylvain Chemtob, Véronique Moulin

The integrity of the cornea is crucial for proper light transmission to the retina. Because of its position at the outer surface of the eye, it is subjected to traumas that may alter the quality of vision. Corneal wound healing involves communication between the three corneal layers (epithelium, stroma and endothelium), a process that is in part ensured by small plasma membrane-derived particles released into the extracellular space by virtually all cell types called exosomes. They have received increased interest because of their capability to carry nucleic acids, proteins, lipids and signaling molecules and to transfer their cargo into the target cells. The goals of this study will be to test the ability of exosomes enriched from the cell types that are present in each of the three corneal layers to improve wound closure of our tissue-engineered, human corneas (hTECs) and to evaluate whether they exert these influences by altering the gene expression and/or activation pattern of signal transduction mediators in corneal epithelial cells. We will also explore the possibility of using exosomes as a vehicle for the delivery of pharmacological compounds known to improve corneal wound healing. This project will expand our understanding of the molecular and cellular events involved in corneal wound healing, a critical step to improve treatments efficacy for corneal traumas and diseases.

Association of hydrogel and pharmacologic pre-treatment to enhance the myoblast transplantation.

Jacques P. Tremblay, Sophie Lerouge, Shant Der Sarkissian, Nicolas Noiseux

Dr. J.P. Tremblay's laboratory is already participating in a clinical trial of myoblast transplantation to treat Duchenne Muscular Dystrophy. The survival of transplanted cells is a major limitation to the success of therapy, this is Why the project aims to improve the survival of these cells. Mortality is due to the lack of extracellular matrix and oxygen, and to inflammation at the injection sites. In order to reduce mortality due to loss of matrix, expertise on hydrogels from Dr. Lerouge's laboratory will be used. We want to study the cells coated in a chitosan gel but also recreate new fibers by associating the coated cells With a support hydrogel such as collagen or fibrin during the transplant. In order to overcome oxidative stress and inflammation, the myoblasts will be conditioned before the transplant With an HSP90 inhibitor from the Celastrol family, already known for its protective, anti-inflammatory and viability and retention potential of cells in cell therapy. The development of myoblast conditioning will be studied in the laboratory of Dr. Der Sarkissian and Dr. Noiseux Who have already worked With this product.

Development of optimized stem cell treatment in regenerative translational medicine

Nicolas Noiseux, Sophie Lerouge, Samer Mansour, Corine Hoesli

Cell therapy is a promising approach for the treatment of degenerative diseases and tissue damages. However, the efficacy of cell therapy remains limited due to the low retention and diminished survival of transplanted cells in diseased microenvironments as well as their poor therapeutic functionality in certain patients. In this proposal, our multidisciplinary team will tackle these impediments by combining two technologies with demonstrated preclinical track record in improving cell therapy. We will combine cell pre-treatment using small molecules with cell encapsulation in hydrogels which both together address the major universal limitations of cell therapy. Moreover, feasibility of cryopreserving the novel combination product will be evaluated as a first step in producing a first of its kind off the shelf therapeutic product for multiple regenerative clinical applications. This proposal involves experts in all required specialisations including surgery, pharmacology and engineering as well as industry and international clinical collaborators with infrastructures ready to receive a new therapeutic product for clinical proof of concept demonstration. Building on their past successes and ongoing collaborations, these teams brought together have the potential to deliver a new therapeutic solution placing Quebec at the forefront of regenerative medicine therapeutics design and delivery.