The present invention relates to a transgenic animal mode system based on the development of transgenic mice bearing components of the human immune system. Specifically, the Invention relates to a Flk2 deficient Rag “γc” transgenic mouse and the engraftment of said mouse with human hematopoietic stem cells. The present invention further presides methods for increasing the numbers of functionally competent human dendritic cells is and the hematopoietic targets cells that they interact with in said transgenic mouse through the administration of Flk2L. The transgenic animal model system of the invention may be used for testing human vaccine candidates, for screening potential Immune adjuvants and for developing novel therapeutics.
