The present invention relates to methods to elicit immature antigen-presenting cells loaded with apoptotic cells or apoptotic bodies. The present invention also relates to methods of obtaining antigen-specific regulatory T cells in vitro or in vivo. Cells loaded with apoptotic bodies/cells and regulatory T cells are obtainable by inducing apoptosis of antigen-presenting cells by cytolytic CD4+ T cells. The cells are used for suppressing or preventing diseases such as autoimmune diseases, graft rejection and allergic diseases, and medicaments related thereto. Further disclosed are the use of antigen-specific regulatory T cells for suppressing or preventing diseases such as autoimmune diseases, graft rejection and allergic diseases, and medicaments related thereto. Further disclosed are populations of antigen-specific regulatory T cells obtained by said method.