Method for generating t-cells compatible for allogenic transplantation

Abstract

The present invention pertains to engineered T-cells, method for their preparation and their use as medicament, particularly for immunotherapy. The engineered T-cells of the invention are characterized in that the expression of beta 2-microglobulin (B2M) and / or class II major histocompatibility complex transactivator (CIITA) is inhibited, e.g., by using rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding B2M and / or CIITA, or by using nucleic acid molecules which inhibit the expression of B2M and / or CIITA. In order to further render the T-cell non-alloreactive, at least one gene encoding a component of the T-cell receptor is inactivated, e.g., by using a rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding said TCR component. In addition, expression of immunosuppressive polypeptide can be performed on those modified T-cells in order to prolong the survival of these modified T cells in host organism. Such modified T-cell is particularly suitable for allogeneic transplantations, especially because it reduces both the risk of rejection by the host's immune system and the risk of developing graft versus host disease. The invention opens the way to standard and affordable adoptive immunotherapy strategies using T-Cells for treating cancer, infections and auto-immune diseases.

Description

FIELD OF THE INVENTION[0001]The present invention pertains to engineered T-cells, method for their preparation and their use as medicament, particularly for immunotherapy. The engineered T-cells of the invention are characterized in that the expression of beta 2-microglobulin (B2M) and / or class II major histocompatibility complex transactivator (CIITA) is inhibited, e.g., by using rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding B2M and / or CIITA, or by using nucleic acid molecules which inhibit the expression of B2M and / or CIITA. In order to further render the T-cell non-alloreactive, at least one gene encoding a component of the T-cell receptor is inactivated, e.g., by using a rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding said TCR component. In addition, a step of expression of immunosuppressive polypeptide such as viral MHCI homolog or NKG2D ligand can be performed on those modified T-cell...

AI Technical Summary

Benefits of technology

The present invention provides methods for preparing engineered T-cells that can be used for immunotherapy purposes. These methods involve inhibiting the expression of certain molecules that are important for immune recognition and histocompatibility. One method involves inhibiting the expression of beta 2-microglobulin (B2M) by using a rare-cutting endonuclease that selectively inactivates the gene encoding B2M. Another method involves inhibiting the expression of class II major histocompatibility complex transactivator (CIITA) by using a rare-cutting endonuclease that selectively inactivates the gene encoding CIITA. The engineered T-cells prepared using these methods can be non-alloreactive and express a chimeric antigen receptor (CAR) directed against malignant or infected cells.

Problems solved by technology

First generation CARs have been shown to successfully redirect T-cell cytotoxicity, however, they failed to provide prolonged expansion and anti-tumor activity in vivo.

Autologous therapies face substantial technical and logistic hurdles to practical application, their generation requires expensive dedicated facilities and expert personnel, they must be generated in a short time following a patient's diagnosis, and in many cases, pretreatment of the patient has resulted in degraded immune function, such that the patient's lymphocytes may be poorly functional and present in very low numbers.

However, the use of allogeneic cells presently has many drawbacks.

In immune-competent hosts allogeneic cells are rapidly rejected, a process termed host versus graft rejection (HvG), and this substantially limits the efficacy of the transferred cells.

In immune-incompetent hosts, allogeneic cells are able to engraft, but their endogenous T-cell receptors (TCR) specificities may recognize the host tissue as foreign, resulting in graft versus host disease (GvHD), which can lead to serious tissue damage and death.

Moreover, HCMV interferes with the NKG2D pathway by secreting a protein able to bind NKG2D ligands and prevent their surface expression [Welte SA et al.

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