Transimmunization methods incorporating skin immunologic challenges are described for either selectively suppressing the immune response of recipients of transplanted tissue or cells or monitoring induced anti-cancer immunity. In one embodiment, skin from the transplant donor is allografted to the transplant recipient to induce an immunological response to the transplanted skin. A quantity of blood is taken from the recipient and treated to render the T cells in the blood apoptotic and to induce differentiation of blood monocytes into dendritic cells. The treated blood is incubated and administered to the recipient to induce formation of suppressor T cell clones which reduce the number of T cells attacking the transplanted tissue or organ. This tolerogenic approach can be complemented by also feeding the immature dendritic cells apoptotic or necrotic cells from the organ donor. In a second embodiment, dendritic cells loaded with tumor antigens are injected intradermally to monitor the anti-cancer immunity induced by Transimmunization.