Immunocompetent xenograft model

An immunocompetent mouse model comprising:

• an immunodeficient mouse modified to have a reconstituted immune system with a simulated T-cell response from exogenously-derived cells obtained from a transgenic mouse that expresses a transgene encoding a non-xenograft specific T-cell receptor (TCR);
• and,
• a xenograft transplanted in the immunodeficient mouse and allowed to establish for an establishment period of at least about 10 days,
• the xenograft simulating a tissue in a subject in need of a treatment;
• wherein,
• the reconstituted immune system is created after the establishment period through the administration of an effective amount of the exogenously-derived cells that provides the simulated T-cell response in the otherwise immunodeficient mouse;
• the exogenously-derived cells comprise a preselected number of potentially responsive T-cells, a preselected number of non-responsive T-cells, and a preselected ratio of potentially responsive T-cells to total T-cells;
• the preselected number of potentially responsive T-cells simulates a number of potentially responsive T-cells in the mouse, and
• the ratio of the number of potentially responsive T-cells to total T-cells ranges from about 1:100,000 to about 30:100,000;
• and
• wherein rejection of the xenograft is inhibited relative to when the immune system of the immunodeficient mouse is reconstituted with T-cells from a wild type mouse.