The present invention relates to an accelerated method to generate high yields of type-1 polarizing mRNA loaded dendritic cells for use in immunotherapy, and in particular for use in cancer vaccination.

Provided are Siglec-based chimeric polypeptides. Accordingly there is provided a chimeric receptor comprising: (a) an extracellular domain comprising an amino acid sequence of a Siglec-7 or a Siglec-9 receptor capable of binding a Siglec-7 and/or a Siglec-9 ligand; and (b) an intracellular domain comprising an amino acid sequence capable of transmitting a co-stimulatory signal in an immune cell expressing the chimeric receptor upon binding of said extracellular domain to said ligand. Also provided are polynucleotides encoding same, cells expressing same and methods of use thereof.

Provided herein are engineered immune cells and populations thereof for administration to patients to treat cancer (e.g., solid tumors or liquid tumors) and other conditions. The cells are engineered to functionally express a reduced level of one or more of RFX5, NLRC5, TAP2, 2m, TRAC, RFXAP, CIITA and RFXANK. The cells optionally are further engineered to express one or more than one additional protein such as an antigen binding protein (e.g., a chimeric antigen receptor (CAR) or T cell receptor) to target tumor cells or other damaged cells in the patient and/or to express other genes at a reduced level. Also provided are methods of making and using the engineered cells, compositions and kits comprising them, and methods of treating by administering the cells and the compositions.

Disclosed herein is a method for enhancing antitumor T cell responses in subjects. The method involves administering to the subject in need thereof a composition comprising a demethylating agent in an amount effective to demethylate STING proteins in the tumor cells. This method is particularly useful in subjects with deficient STING expression in the tumor cells. Therefore, also disclosed is a method for treating a tumor in a subject that involves detecting in a biopsy sample from the subject reduced STING expression, reduced cGAS expression, or a combination thereof; and then administering to the subject a demethylating agent in an amount effective to demethylate STING proteins in the tumor cells. The method can further involve administering to the subject a therapeutically effective amount of a STING agonist. The method can further involve administering to the subject tumor infiltrating lymphocytes (TILs), such as HLA-matched TILs.

Disclosed herein is a method for ex vivo expanding tumor-infiltrating lymphocytes for use in adoptive cell therapy (ACT). The method involves culturing tumor fragments from the subject in a culture medium containing IL-2 and a 41BB agonist in an amount effective to expand tumor-infiltrating lymphocytes with enriched tumor-reactivity and specificity. Also disclosed is a method for treating a tumor in a subject that involves treating the subject with nonmyeloablative lymphodepleting chemotherapy, and administering tumor-infiltrating lymphocytes expanded by the disclosed methods.

Disclosed are nucleic acids and polypeptides which provide the co-expression of interleukin (IL)-21 and IL-15 by a host cell, each interleukin being bound to the cell membrane by a cell membrane anchor moiety. Also disclosed are related recombinant expression vectors, host cells, populations of cells, pharmaceutical compositions, and methods of treating or preventing cancer.