Experimental models to study development and function of the human immune system in vivo

The study of development and function of the immune system in vivo has made intensive use ofanimal models, but performing such work in humans is difflcultfor experimental, practical and ethical reasons. Conftonted with this scientific challenge, several pioneering groups have developed in the late 1980s mouse models ofhuman immune system development. Although these experimental approaches were proven successful and useful they were sufferingftom limitations due to xenograft transplantation barriers. By reviewing the characteristics of the successive model over the last 20 years, it becomes apparent that screening ofpotentially interesting mouse strains and usage of combinations of genetic deficiencies has led to major advances. This is particularly true for human T cell development in the murine thymus. This review will focus on these advances and the potential future improvements that remain to be accomplished.