Agents and methods to elicit anti-tumor immune response
Inventors
Gu, Hua • Hodes, Richard • Chiang, Jeffrey J. • Jang, Ihnkyung
Assignees
Columbia University in the City of New York • US Department of Health and Human Services
Publication Number
US-9334522-B2
Publication Date
2016-05-10
Expiration Date
2027-09-13
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The invention provides an isolated, purified population of human cells comprising CD8+ T cells with reduced Cbl-b activity. The invention provides uses of such cells in methods for inducing or enhancing an anti-tumor immune response in a subject. These methods comprise: (a) providing a cell population, from a subject or from another source, which comprises CD8+ T cells, (b) reducing Cbl-b activity in the CD8+ T-cells, (c) administering the cells of step (b) to the subject. The invention provides methods for making CD8+ T cells that do not require stimulation through a co-receptor in order for the cell to become activated or proliferated in response to contact via its T cell receptor. Such methods are based upon reducing function of Cbl-b. The invention also provides methods for identifying agents which affect Cbl-b expression or activity.
Core Innovation
The invention provides isolated, purified populations of human CD8+ T cells with reduced Cbl-b activity, which do not require stimulation through a co-receptor to become activated or proliferate upon contact via their T cell receptor (TCR). Methods are described for making such CD8+ T cells by reducing or eliminating Cbl-b function or expression, including knockdown by siRNA or knockout of the gene. These modified CD8+ T cells can stimulate or enhance an anti-tumor immune response upon administration to a subject, including subjects suffering from tumors.
The need addressed arises from the background that most antigenic tumors are not rejected despite the presence of tumor-infiltrating cytotoxic T lymphocytes (CTLs) due to mechanisms such as low tumor immunogenicity, lack of co-stimulatory ligands like B7 on tumor cells, active suppression by tumor-derived factors like TGF-beta, and immunoregulatory host mechanisms. Tumor-specific CTLs often require two signals—TCR engagement and co-stimulation via receptors like CD28—for full activation; absence of the latter results in T cell anergy and failure of tumor rejection. Existing methods of enforcing co-stimulatory ligand expression on tumors or using dendritic cells for antigen presentation have limitations in eliciting efficient anti-tumor responses.
The core innovation proposes methods to render CD8+ T cells independent of co-stimulation by reducing Cbl-b activity, thereby enabling these so-called “super killer” T cells to be activated solely by TCR engagement. These Cbl-b-deficient CD8+ T cells are shown to produce substantial cytokines, resist suppression by TGF-beta, infiltrate tumors extensively, and mediate tumor rejection in vivo, including eradication of established tumors upon adoptive transfer. Methods also include identifying agents that inhibit Cbl-b expression or activity and using them therapeutically to induce anti-tumor immune responses without co-administration of vaccines or cytokines.
Claims Coverage
The patent includes ten main inventive features based on independent claims, focusing on methods for making co-stimulation-independent CD8+ T cells, inducing anti-tumor immune responses via reduced Cbl-b activity, methods of administration, and techniques for reducing Cbl-b activity.
Method for creating CD8+ T cells independent of co-stimulation
A method comprising providing CD8+ T cells and reducing Cbl-b activity in these cells to generate CD8+ T cells that do not require co-stimulation for activation and proliferation.
Method for inducing an anti-tumor immune response by administering modified CD8+ T cells
A method including providing CD8+ T cells, reducing their Cbl-b activity, and administering these cells to a subject to induce an anti-tumor immune response.
Sources of CD8+ T cells for modification
CD8+ T cells used for reduction of Cbl-b activity can be obtained from peripheral blood, lymph organs, or tumor infiltrates of subjects.
Inducing anti-tumor immune response with subject-derived CD8+ T cells
Isolating CD8+ T cells from the subject, reducing Cbl-b activity in these cells, and administering them back to the same subject.
Stimulating proliferation of modified CD8+ T cells after Cbl-b reduction
Following Cbl-b activity reduction, CD8+ T cells can be stimulated to proliferate, including by anti-CD3 antibody and/or IL-2 exposure.
Increasing tumor-specific CD8+ T cells by stimulation with tumor cells
Mixing the CD8+ T cells with tumor cells isolated from the subject to increase numbers of tumor-specific CD8+ T cells.
Further stimulation of tumor-specific CD8+ T cells
Contacting tumor-specific CD8+ T cells with anti-CD3 antibody or IL-2, separately or combined, to further expand these cells.
Use of siRNA to reduce Cbl-b activity
Reducing Cbl-b activity by introducing siRNA targeting Cbl-b into CD8+ T cells, specifically including siRNA of SEQ ID NO: 1.
Treatment of specific tumor types
The subject in methods may suffer from melanoma, lymphoma, or solid tumors expressing MHC-I with antigens recognizable by CTLs.
Use of specific siRNA sequence for Cbl-b inhibition
Use of siRNA having the nucleotide sequence 5′-CAGGAGTATGAGACAGAAG-3′ (SEQ ID NO: 1) to reduce Cbl-b activity in CD8+ T cells.
The claims cover methods for producing CD8+ T cells independent of co-stimulation by reducing Cbl-b activity, administering these cells to induce anti-tumor immune responses, approaches for stimulating proliferation and specificity, and employing siRNA sequences to achieve Cbl-b reduction, including treatment of various tumor types.
Stated Advantages
Cbl-b−/− CD8+ T cells function independent of CD28 co-stimulation and CD4+ T cell help, allowing activation by TCR alone.
Such CD8+ T cells exhibit resistance to TGF-beta suppression, overcoming tumor-mediated immune suppression.
Adoptive transfer of Cbl-b deficient CD8+ T cells can effectively eradicate established tumors, including strong and weak antigenic tumors.
Ablation of Cbl-b enhances tumor infiltration by CD8+ T cells, improving immune surveillance and tumor rejection.
Use of Cbl-b modulation may avoid the need for exogenous cytokines or vaccines to boost costimulatory signaling.
Reduction of spontaneous tumors in ATM−/− mice demonstrates potential tumor-preventive effects by systemic Cbl-b inhibition.
Documented Applications
Use of CD8+ T cells with reduced Cbl-b activity to induce or enhance anti-tumor immune responses in subjects suffering from tumors.
Cancer immunotherapy including adoptive transfer of Cbl-b deficient CD8+ T cells derived from peripheral blood, lymph organs, or tumor infiltrates.
Treatment of specific tumor types such as melanoma, lymphoma, and solid tumors expressing MHC-I with CTL-recognizable antigens.
Generation of 'super killer' CD8+ T cells for therapeutic use by reducing Cbl-b activity via siRNA or gene knockout.
Screening and identification of agents that modulate Cbl-b activity for possible therapeutic use.
Interested in licensing this patent?