Abstract: Methods are provided for producing a population of substantially purified CD4+ Th1 lymphocytes. The method includes stimulating a population of substantially purified CD4+ T cells isolated from a subject by contacting the population with an anti-CD3 monoclonal antibody and an antibody that specifically binds to a T cell costimulatory molecule in the presence of a Th1 supportive environment to form a stimulated population of T cells. The stimulated population of CD4+ T cells is allowed to proliferate in a Th1 supportive environment. In one example, the Th1 supportive environment includes at least 20 IU/ml of IL-2, for example about 1000 I.U./ml of IL-2, and a neutralizing amount of an IL-4, an IL-13, and/or an IL-4/IL-13 neutralizing agent. In other examples, the supportive environment further includes at least 1 ng/ml of IL-12, for example about 2.5 ng/ml of IL-12. Purified populations of Th1 cells are disclosed herein, as are methods for their use.

Abstract: A method is provided for producing a population of substantially purified CD4+ Th2 lymphocytes. The method includes stimulating a population of substantially purified CD4+ T cells isolated from a subject by contacting the population with an immobilized anti-CD3 monoclonal antibody and an immobilized antibody that specifically binds to a T cell costimulatory molecule in the presence of a Th2 supportive environment to form a stimulated population of T cells. Purified populations of Th2 cells are disclosed herein, as are methods for their use. For example, substantially purified CD4+ Th2 lymphocytes can be used to treat graft-versus-host-disease, tumors, and autoimmune disorders.