Methods of generating antigen-specific CD4+CD25+regulatory T cells, compositions and methods of use

A method for generating a T cell population comprising human antigen-specific CD4+CD25+regulatory T cells from freshly isolated CD4+CD25− T cells, the method comprising:

• (a) isolating CD4+CD25− T cells from a sample comprising T cells obtained from a human subject;
• (b) determining the MHC Class II type of the subject;
• (c) inducing generation of antigen-specific regulatory T cells by contacting the isolated CD4+CD25− T cells in a culture vessel with a CD4+CD25+induction agent comprising one or more antigenic peptide(s) and a population of MHC expressing antigen presenting cells that are MHC class II matched to the subject, for a time period sufficient to generate antigen-specific CD4+CD25+regulatory T cells;
• (d) selecting the CD4+CD25+antigen-specific regulatory T cells by sorting the cells in the induction culture with a selection agent comprising at least one artificial multimeric MHC Class II/peptide complex, wherein the MHC Class II/peptide complex is chosen to correspond to the MHC Class II type of the subject;
• (e) isolating the subpopulation of cells selected from the induction culture of step (d) that express CD25+, wherein at least 70% of the subpopulation of cells isolated from the induction culture bind to the corresponding MHC Class II/peptide tetramer complex and are CD4+CD25+antigen-specific regulatory T cells;
• and
• (f) assaying at least a portion of cells isolated according to step (e) for FoxP3 expression, wherein the CD4+CD25+antigen specific regulatory T cells express FoxP3.