Research overview

CRISPR/Cas9 genome editing of hematopoietic stem and progenitor cells

CRISPR/Cas9 genome editing of hematopoietic stem and progenitor cells (HSPCs) to correct IL-10 and IL-10 receptor deficiency

Very early onset inflammatory bowel disease (VEO-IBD) is a rare and severe infantile form of IBD. The most common genetic defects causing VEO-IBD are mutations in IL10 or IL10R genes. VEO-IBD patients with IL10 or IL10R mutations are refractory to standard medical treatment, such as immunosuppressive therapies. Allogeneic HSPC transplantation (allo-HSPCT) can provide a curative therapy, but its use is limited by compatible donor availability, and high morbidity and mortality due to the graft-vs-host disease (GvHD). As an alternative therapeutic approach, we are developing a CRISPR/Cas9 strategy that inserts a wild type (WT) cDNA copy of either the IL10 or IL10RA gene directly into the genomic loci of patient HSPCs. The inserted gene is expressed via the endogenous promoter, and the mutant gene is no longer transcribed or translated. Such autologous engineered HSPCT will overcome the issues of donor availability, and the autologous transplant will not cause GvHD, providing a definitive and curative treatment to the children with this debilitating and often lethal genetic disease.

Adoptive therapy with Tr1 cells to improve outcomes of hematopoietic stem cell transplantation

Induction of alloantigen specific Tr1 cells for clinical use: T-allo10

The curative potential of hematopoietic stem and progenitor cell transplantation (HSPCT) is limited by the frequent occurrence of graft-versus-host disease (GvHD), a life-threatening complication mediated by alloreactive donor T cells that recognize and compromise healthy tissues in the host. We developed a novel and highly reproducible method to produce a cell product, called T-allo10, consisting of donor-derived CD4+ T cells which contain a high proportion of host alloantigen specific Tr1 cells. The T-allo10 cell therapy product is designed to suppress GvHD during allo-HSPCT, and is currently tested in patients with hematological malignancies in a phase I/II clinical trial (NCT03198234).

Lentiviral engineering of Tr1 cell development: LV-10    

In order to prepare a highly purified Tr1 cell product for clinical use, we have developed a method to in vitro engineer healthy donor CD4+ T cells, by inserting the IL10 gene using a lentiviral vector.  These engineered cells, called LV-10, acquire a typical Tr1 phenotype and function. We are currently examining their capacity to prevent GvHD and mediate anti-leukemic effect in AML in in vivo models.   

Biology of Tr1 cells


Identifying genes driving the development and maintenance of human Tr1 cells

To better understand the molecular machinery conferring the Tr1 identity, we aim at examining the transcriptome and epigenome of freshly isolated and in vitro induced Tr1 cells. Also, we have begun to characterize the TCR repertoire of Tr1 cells. 

Function and mechanisms of action

Function and mechanisms of action 

Tr1 cells can suppress effector T cell responses and kill malignant myeloid cells. We aim to refine our understanding of the function, regulation, and therapeutic potential of Tr1 cells. We have screened a panel of primary acute myeloid leukemia (AML) samples against in vitro generated Tr1 cells to better understand the mechanisms of killing. We identified a range of AML sensitivities to Tr1 killing, and novel AML genes that mediate the resistance to Tr1 killing. 

Collaborative Projects

Understanding the relationship between different CD4+ T helper and T regulatory cell subsets by mass cytometry

Elucidating the interrelationship between CD3+ CD4+ T helper and T regulatory cell populations is critical to provide a deeper understanding of the immune system, which will pave the way for a comprehensive analysis in immune-mediated diseases.

In the Roncarolo/Bacchetta Lab, by evaluating the differential expression of transcription factors, chemokine-, activation-, and inhibitory-receptors, among others, using Cytometry by time-of-flight (CyTOF) we aim at characterizing each human Th, Treg, and Tr1 cell populations in healthy human blood and in patients with immune dysregulation, referred by the Center of Genetic Immune Diseases.

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