This invention relates to a transgenic non-human mammal whose genome comprises a polynucleotide sequence encoding a T cell receptor that is specific to a fluorescent protein, where the T cell of the non-human mammal comprises the T cell receptor. The present invention also relates to an isolated T cell from the transgenic non-human mammal of the present invention , an isolated T cell comprising an expression construct comprising a polynucleotide sequence that encodes a T cell receptor that is specific to a fluorescent protein, methods of making transgenic non-human mammals comprising T cell receptors that are specific to a fluorescent protein, a method of depleting cells in a non-human mammal using isolated T cells that encode a T cell receptor that is specific to a target protein, and a method of characterizing a T cell response to an agent.
