Cancer is a leading a cause of death among older pets, affecting 1 in 4 dogs. In the past, dog owners considered cancer to be a terminal disease and rarely pursued aggressive treatment options. However, with the tremendous success of immunotherapy for the treatment of cancer in humans, more owners are demanding these cutting-edge treatments for their beloved pets. To meet this challenge, we will develop novel platforms for the production of canine CD8+ T cells and NK cells that are ideally suited for oncological applications. In Aim 1, we will generate artificial thymic organoids for the complete development of canine CD8+ T cells. In Aim 2, we will pioneer the development of canine NK cells with enhanced anti-tumor functions. Once established, these new systems may provide the field with a universal source of ‘off-the-shelf’ cancer fighting lymphocytes at an affordable price.