Methods for induction of antigen-specific regulatory t cells

An in vitro method of obtaining antigen-specific regulatory T cells or antigen-specific regulatory NKT cells, said method comprising the steps of:

• a) providing antigen-specific NKT cells for a proteic antigen, the antigen comprising an [WFYHT]-X-X-[VILM]-X-X-[WFYHT] sequence motif of a NKT cell peptide epitope, which epitope is capable of binding to a CD1d molecule, and which antigen-specific NKT cells are obtained by contacting peripheral cells with a peptide comprising said epitope and a C-X-X-[CST] or [CST]-X-X-C redox motif;
• b) providing antigen presenting cells (APCs) presenting said antigen;
• c) inducing apoptosis of the APCs of b) by exposing said APCs to the antigen-specific NKT cells of a);
• d) isolating apoptotic cells or apoptotic bodies from the APCs which underwent apoptosis in step c);
• e) incubating said apoptotic cells or said apoptotic bodies of step d) with cells capable of presenting antigens from said apoptotic cells or from said apoptotic bodies, thereby obtaining APCs loaded with apoptotic cells or apoptotic bodies and;
• f) contacting said loaded APCs obtained in step e), with a source of class II restricted CD4+ T cells, thereby obtaining a population of antigen-specific regulatory T cells, or with a source of CD1d restricted CD4+ NKT cells, thereby obtaining a population of antigen-specific regulatory NKT cells.