An oncolytic virus with improved safety and anticancer effects and uses thereof are disclosed. The oncolytic virus contains a recombinant nucleic acid including a nucleotide sequence encoding an effector domain derived from herpes simplex virus thymidine kinase (HSV-TK). The oncolytic virus can express an HSV-TK fragment which contains an effector domain composed of a minimum amino acid sequence capable of phosphorylating GCV or ACV while having no thymidine kinase (TK) activity, or a variant thereof to phosphorylate GCV or ACV, thereby killing cancer cells infected with the oncolytic virus and even neighboring cancer cells.

Nucleic acid sequences encoding improved Herpes Simplex Virus Thymidine Kinases are provided, including their use in diagnostic and therapeutic applications. The thymidine kinases may be mutated using conservative mutations, non-conservative mutations, or both. Also provided are gene therapeutic systems, including viral and retroviral particles.

The present application relates, in some aspects, to the development of an assay that uses cell survival and/or cell viability as a phenotypic identifier to positively select for agents that destabilize a protein of interest.

Disclosed is a gene therapy vector in which the occurrence of recombination is minimized. In order to minimize the occurrence of recombination, which is a major problem in the production and infection of a retroviral vector virus that continuously expresses a therapeutic gene during virus replication, a cleaved MCMV promoter was prepared by cutting the MCMV promoter on the basis of a repeat sequence, and the cleaved MCMV promoter was introduced to prepare a vector. It was confirmed that the vector having the cleaved MCMV promoter incorporated therein does not cause recombinations even after being incubated multiple times, and shows a continuous expression of the therapeutic protein, and in cells transfected with the virus containing the vector, cell death effectively occurs when a prodrug is administered thereto. Accordingly, the vector with minimized recombination occurrence of the present invention can be advantageously used for the treatment of cancer.

Provided herein are methods and compositions for a suicide gene approach comprising an expression vector comprising a cell cycle-dependent promoter driving the expression of a suicide gene. Also provided herein are methods to render proliferative cells sensitive to a prodrug after transplantation but avoids expression of the suicide gene in post-mitotic cells, such as neurons.

Methods of treating a cancer in a patient are provided. The methods can include obtaining a tumor sample from a patient, detecting whether CCNG1 gene expression is present in the tumor sample, diagnosing the patient with a CCNG1 inhibitor-responsive cancer when the presence of CCNG1 gene expression in the tumor sample is detected, and/or administering an effective amount of a CCNG1 inhibitor to the diagnosed patient. CCNG1 inhibitors can include a viral vector having a binding peptide that is configured to bind one or more signature (SIG) elements of an invading tumor and at least one cytocidal gene. CCNG1 inhibitors including cell penetrating peptides are also provided.

The disclosure provides compositions and methods for inducing an immunity via cellular expression of an antigen receptor binding construct in vivo.

Nucleic acid sequences encoding improved Herpes Simplex Virus Thymidine Kinases are provided, including their use in diagnostic and therapeutic applications. The thymidine kinases may be mutated using conservative mutations, non-conservative mutations, or both. Also provided are gene therapeutic systems, including viral and retroviral particles.

The present disclosure provides an engineered stem cell, comprising a vector comprising a polynucleotide comprising a nucleic acid sequence of suicide gene, a nucleic acid sequence of immune checkpoint gene and a natural cytotoxicity triggering receptor or a TNF-related apoptosis-inducing ligand, wherein the stem cell is a tumor-targeting cell. The present disclosure also provides a method for treating a cancer or enhancing intratumor immunity or enhancing immunity in tumor microenvironment in a subject, comprising administering an effective amount of the engineered stem cell of the present disclosure to the subject.

Some embodiments of the methods and compositions provided herein relate to chimeric cytokine receptors. In some embodiments, a chimeric cytokine receptor can include an IL-7 tethered to an extracellular IL-7 receptor domain, and an intracellular IL-21 receptor domain linked to the extracellular IL-7 receptor domain. In some embodiments, a T cell containing a chimeric cytokine receptor can be readily activated and/or expanded in the absence of an exogenous cytokine.