CTLA-4-targeting trans-splicing ribozyme for delivery of chimeric antigen receptor, and use thereof

Inventors

Lee, Seong Wook • Yang, Bit Na • Kim, Sung Jin • Han, Seung Ryul

Assignees

Rznomics Inc

Abstract

The present invention relates to a recombinant vector, characterized by including a cytotoxic T-lymphocyte-associated protein-4 (CTLA-4)-targeting trans-splicing ribozyme expression cassette for delivery of chimeric antigen receptor, wherein the expression cassette includes: (i) a CTLA-4-targeting trans-splicing ribozyme; and (ii) a polynucleotide encoding a chimeric antigen receptor ligated to the 3′ exon of the ribozyme. The present invention also relates to a transformed cell into which the recombinant vector is introduced, a ribozyme expressed from the recombinant vector, a retrovirus expressing the ribozyme, and a T cell treated with the retrovirus. Furthermore, the present invention relates to a pharmaceutical composition for preventing or treating cancers, in which the pharmaceutical composition includes the recombinant vector, the transformed cell, the ribozyme, the retrovirus, the T cell, or a combination thereof; and a method for treating cancers, in which the method includes administering, to an individual in need thereof, the recombinant vector, the transformed cell, the ribozyme, the retrovirus, the T cell, or a combination thereof. The recombinant vector of the present invention and the ribozyme expressed therefrom become a gene-cell therapy which inhibits CTLA-4 on T cells which has been an obstacle in conventional anti-cancer therapies and, at the same time, enables anti-cancer treatment, thereby allowing more effective anti-cancer effects to be anticipated. Such a gene-cell therapy results in decreased toxicity in normal tissues and thus exhibits increased effects in both therapeutic efficacy and safety, which enables it to be widely utilized in the field of gene therapy in the future.

Core Innovation

The invention describes a CTLA-4-targeting trans-splicing ribozyme expression cassette used to deliver a chimeric antigen receptor. The expression cassette includes a CTLA-4-targeting trans-splicing ribozyme and a polynucleotide encoding a chimeric antigen receptor connected to the 3′ exon of the ribozyme. This arrangement is presented for delivery of the chimeric antigen receptor in a gene-cell therapy context.

The document identifies CTLA-4 RNA targeting internal guide sequences for the trans-splicing ribozyme, including IGS32, IGS48, IGS111, and IGS232, with IGS48 described as a common site. Embodiments include selection among nucleic-acid sequence options referenced as SEQ ID NOs, and ribozymes based on selected IGSs are described as enabling trans-splicing with target-dependent increased efficiency. The document further describes that this can allow “leaky” CAR expression while reducing CTLA-4 RNA while supporting CAR expression.

The disclosure describes use in transformed cells and retroviral delivery forms, including retroviruses expressing the ribozyme and CTLA-4-inhibited CAR T cells. It characterizes the resulting system as for cancer prevention and treatment, aiming for enhanced efficacy and reduced normal-tissue toxicity. Experimental support described in the partial content includes reporter assays, measurement of CTLA-4 and CAR expression, and cytotoxicity against Tag72+ LS174T cells relative to CAR-only controls.

Claims Coverage

The document includes one independent claim focused on a recombinant vector architecture, with dependent claims refining the CTLA-4-targeting ribozyme sequences, additional ribozyme elements, and downstream uses including pharmaceutical compositions and administration methods. The independent claim includes two inventive elements: a CTLA-4-targeting trans-splicing ribozyme and a chimeric antigen receptor polynucleotide connected to the 3′ exon of the ribozyme.

Across the provided claims, the core coverage centers on the recombinant vector that couples a CTLA-4-targeting trans-splicing ribozyme to CAR delivery, specifically by connecting the CAR-encoding polynucleotide to the ribozyme 3′ exon. Dependent claims refine CTLA-4 ribozyme sequence choices by SEQ ID and add an antisense element at the ribozyme 5′ end tied to the CTLA-4 recognition site, and then extend into pharmaceutical composition and treatment administration use cases.

Stated Advantages

Documented Applications