Lyz2^(Cre)介导的黄色荧光蛋白标记荷瘤小鼠不同部位髓系免疫细胞的效率检测

Efficiency detection of Lyz2^(Cre)mediated yellow fluorescent protein labeling of myeloid immune cells in different parts of tumor-bearing mice

目的评价Lyz2^(Cre)介导的黄色荧光蛋白(YFP)标记荷瘤小鼠不同部位髓系免疫细胞的特异性及其效率。方法Lyz2^(Cre)小鼠与Rosa26RYFP小鼠交配,通过PCR基因型鉴定筛选出双阳性子代小鼠,待小鼠成年后,建立皮下肿瘤移植模型,14 d后,分离外周血、骨髓以及肿瘤中的免疫细胞,利用流式细胞术分析不同部位髓系免疫细胞中YFP的标记效率。结果外周血中单核细胞表达YFP的比例为(36.87±2.03)%;中性粒细胞表达YFP的比例为(78.46±0.84)%;骨髓中单核细胞表达YFP的比例为(15.13±1.17)%;中性粒细胞表达YFP的比例为(69.62±1.75)%;肿瘤中单核细胞表达YFP的比例为(32.89±1.89)%;中性粒细胞表达YFP的比例为(65.56±4.17)%;肿瘤相关巨噬细胞表达YFP的比例为(40.80±3.89)%。结论Lyz2^(Cre)介导的YFP对于示踪某一类髓系免疫细胞的特异性和效率不高;Lyz2^(Cre)作为肿瘤髓系巨噬细胞的基因条件性敲除小鼠存在一定的缺陷。

Objective To evaluate the specificity and efficiency of Lyz2^(Cre)mediated yellow fluorescent protein(YFP)labeling of myeloid immune cells in different parts of bodies of mice.Methods Lyz2^(Cre)mice were mated with Rosa26RYFPmice,and double‐positive offspring mice were screened via PCR genotype identification.Once the mice became adults,a subcutaneous tumor transplantation model was established.After 14 days,immune cells from peripheral blood,bone marrow and tumors were isolated.Flow cytometry analysis was performed of YFP labeling efficiency in myeloid immune cells at different sites.Results The percentage of monocytes that expressed YFP was(36.87±2.03)%in peripheral blood,compared with(78.46±0.84)%for neutrophils,(15.13±1.17)%for monocytes and(69.62±1.75)%for neutro‐phils in bone marrow,(32.89±1.89)%for monocytes and(65.56±4.17)%for neutrophils in tumors.The proportion of tumor‐associated macrophages expressing YFP was(40.80±3.89)%.Conclusion Lyz2^(Cre)mediated YFP might be not specific and efficient for tracking a particular type of myeloid immune cells.Lyz2^(Cre)gene conditional knockout mice as tumor myeloid macrophages have some defects.