Provided herein are methods for ex vivo expansion of a T cells, including tumor-reactive T cells, and compositions containing such T cells. Also provided are methods for treating diseases and conditions such as cancer using compositions of the present disclosure.

The present invention relates to a method for in vitro cultivation of hematopoietic and/or mesenchymal cells, wherein said cells are cultivated in a cultivation medium comprising gamma-aminobutyric acid (GABA) or a GABA receptor agonist, to cells obtained by such a method and therapeutic use of such cells in methods of treatment of autoimmune, inflammatory or allergic disorder. The invention further relates to pharmaceutical compositions comprising the cells and cultivation media for use in the method according to the invention.

The invention is directed to a method of preparing B-cells that produce interleukin-10 (IL-10), or IL-10 per se, which comprises contacting one or more B-cells ex vivo with an isolated interleukin-35 (IL-35) protein, and culturing the one or more B-cells under conditions to provide one or more B-cells that produce IL-10. The invention also is directed to a method of suppressing the proliferation of lymphocytes in vitro or in vivo by contacting lymphocytes with an isolated IL-35 protein. The invention further is directed to a method of suppressing autoimmunity in a mammal by administering to the mammal an IL-35 protein or IL-10-producing B-cells.