Cd4+ Cd25+ T-cells activated to a specific antigen

A method of assessing whether a subject comprises CD4+, CD25+high T cells that have been activated to a specific non-self antigen, and is therefore tolerant, or capable of becoming tolerant, to the specific non-self antigen, the method of comprising:

• (a) in a first culture, incubating a first portion of a population of T lymphocytes comprising, CD4+, CD25+high T cells obtained from the subject in the presence of (i) one or more cytokines selected from the group consisting of IL-5, IL-12 and IFN-γ, wherein the one of more cytokines are isolated or purified proteins or are contained in supernatant from a CHO—K1 cell transfected with a nucleic acid which expresses the one or more cytokines in the CHO—K1 cell so that the transfected CHO—K1 cell produces the one or more cytokines, and (ii) the specific non-self antigen bound to the surface of an antigen presenting cell, wherein the proliferation of the antigen presenting cell has been impaired, or the specific non-self antigen bound to a synthetic antigen presenting system;
• (b) in a second culture, incubating a second portion of a population of T lymphocytes comprising CD4+, CD25+high T cells obtained from the subject in the presence of (i) one or more cytokines selected from the group consisting of IL-5, IL-12 and IFN-γ, wherein the one or more cytokines are isolated or purified proteins or are contained in supermatant from a CHO—K1 cell transfected with a nucleic acid which expresses the one or more cytokines in the CHO—K1 cell so that the transfected CHO—K1 cell produces the one or more cytokines, and (ii) a self antigen bound to the surface of an antigen presenting cell, wherein the proliferation of the antigen presenting cell has been impaired, or a self antigen bound to a synthetic antigen presenting system;
• and
• (c) detecting proliferation or survival of CD4+CD25+high T cells in the first culture and the second culture, wherein when the CD4+CD25+high T cell proliferation or survival in the fast culture exceeds the CD4+CD25+high T cell proliferation or survival the second culture, wherein said subject comprises CD4+CD25+high T cells that have been activated to the specific non-self antigen, and is therefore tolerant, or capable of becoming tolerant, to the specific non-self antigen, when the CD4+CD25+high T cell proliferation or survival in the first culture exceeds the CD4+CD25+high T cell proliferation or survival in the second culture.