Generation of Humanized Mice for Analysis of Human Dendritic Cells

Transplantation of human CD34(+) hematopoietic stem and progenitor cells into severe immunocompromised newborn mice allows the development of a human hemato-lymphoid system (HHLS) including dendritic cells (DCs) in vivo. Therefore, it can be a powerful tool to study human DC subsets, residing in different lymphoid and nonlymphoid organs. We have recently generated novel mouse strains called human cytokine knock-in mice in which human versions of several cytokines are knocked into Rag2(-/-)γC(-/-) strains. In addition, human SIRPα, which is a critical factor to prevent donor cell to be eliminated by host macrophages, is expressed as transgene. These mice efficiently support human myeloid cell development and, indeed, allow the analysis of three major subsets of human DC lineages, plasmacytoid DCs and CD1c(+) and CD141(+) classical DCs. Moreover, these strains also support cytokine-mobilized peripheral blood CD34(+) cell engraftment and subsequent DC development. Here we describe our standard methods to characterize DCs developed in human cytokine knock-in mice.