Studies on dynamics of plasmacytoid dendritic cells by gene-targeting technology.

为了在体内追踪浆细胞样树突状细胞（pDCs），我们制造了SiglecH荧光蛋白和SiglecH-cre重组酶敲入小鼠，将一种荧光蛋白和一种cre重组酶的基因敲入在pDC中高表达的SiglecH基因位点。在siglech荧光蛋白敲入小鼠中，不仅在大多数pDC中检测到荧光阳性细胞，而且在脾脏和Peyer斑块中也检测到少量CD8+树突状细胞。我们观察到SiglecH-cre: Rosa-loxP-STOP-loxP-tdRFP小鼠的所有血细胞都呈tdrfp阳性，这些小鼠携带了表达tdrfp阳性的细胞。这些数据表明，我们不能通过使用这些敲入小鼠在体内标记和跟踪pDCs。我建议我们选择其他在pDCs中高度特异性表达的基因，并产生新的敲入小鼠系在体内标记pDCs。

In order to track plasmacytoid dendritic cells (pDCs) in vivo, we generated SiglecH-fluorescent protein and SiglecH-cre recombinase knock-in mice, in which genes for a fluorescent protein and a cre recombinase were knocked into the gene locus of a SiglecH expressed highly in pDC. In SiglecH-fluorescent protein knock-in mice, fluorescent-positive cells were detected not only in the majority of pDC, but also in a small population of CD8+ dendritic cells in spleen and Peyer's patches. We observed all of the blood cells analyzed were tdRFP-positive in SiglecH-cre: Rosa-loxP-STOP-loxP-tdRFP mice, which carry cre-expressing tdRFP-positive cells. These data suggest that we cannot label and track pDCs in vivo by use of these knock-in mice. I propose that we choose other genes highly and specifically expressed in pDCs, and generate new knock-in mouse line to label pDCs in vivo.