BACKGROUND The Cre-lox system is a non-dynamic method of gene modification and characterization. Promoters thought to be relatively cell-specific are utilized for generation of cell-lineage-specific gene modifications. METHODS CD11c.Cre+ITGA4fl/fl mice were generated to abolish the expression of ITGA (α4-integrin) in CD11c+ cells. Ex vivo flow cytometry studies were used to assess the expression of cellular surface markers in different lymphoid compartments and leukocytes subsets after Cre-mediated recombination. RESULTS A significant reduction of α4-integrin expression among CD11c+- cells was achieved in CD11c.Cre+ITGA4fl/fl mice in primary and secondary lymphoid tissues. A similar reduction in the expression of α4-integrin was also observed in CD11c- cells. CONCLUSION Cre-lox-mediated cell lineage-specific gene deletion is limited by the transient expression of recombination regulating sequences in hematopoietic cell lines. These methodological issues indicate the need to consider when to employ non-dynamic DNA recombination models in animal models of CNS autoimmunity. An experimental algorithm to address the biological complexities of non-dynamic gene recombination is provided.

中文翻译：

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CD11c.Cre+ITGA4fl/fl 小鼠细胞谱系特异性非动态基因重组的局限性

背景Cre-lox系统是一种基因修饰和表征的非动态方法。被认为具有相对细胞特异性的启动子用于产生细胞谱系特异性基因修饰。方法 产生 CD11c.Cre+ITGA4fl/fl 小鼠以消除 CD11c+ 细胞中 ITGA（α4-整合素）的表达。离体流式细胞术研究用于评估 Cre 介导的重组后不同淋巴区室和白细胞亚群中细胞表面标志物的表达。结果 在 CD11c.Cre+ITGA4fl/fl 小鼠的初级和次级淋巴组织中，CD11c+- 细胞中 α4-整联蛋白的表达显着降低。在 CD11c- 细胞中也观察到 α4-整联蛋白表达的类似降低。结论 Cre-lox 介导的细胞谱系特异性基因缺失受到造血细胞系中重组调节序列的瞬时表达的限制。这些方法问题表明需要考虑何时在 CNS 自身免疫动物模型中使用非动态 DNA 重组模型。提供了一种解决非动态基因重组的生物学复杂性的实验算法。