Kaminski Denise A, Stavnezer Janet
Immunology and Virology Program, Department of Molecular Genetics and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Int Immunol. 2007 Apr;19(4):545-56. doi: 10.1093/intimm/dxm020. Epub 2007 Feb 27.
Inbred mouse strains used for gene manipulation studies vary in many respects, including immune system function. These differences can interfere with data interpretation unless the mice are well backcrossed. Here, we show that antibody class switching to IgG3 in cultured splenic B cells from Swiss James Lambert (SJL) and 129/Sv mice is 2- to 6-fold less efficient compared with C57BL/6 (B6). Under optimal stimulation conditions, IgA switching is also 2- to 19-fold lower in SJL and 129/Sv B cells. Splenic B cells from SJL mice express higher levels of CD19 and CD21 compared with B6, and their CD21(high)CD23(low) B cells have little CD9 expression, suggesting atypical marginal zone (MZ) B cells. However, sort purification of splenic B cell subsets did not equalize in vitro class switching to IgG3 or IgA between SJL and B6. 129/Sv spleens have a 3-fold greater number of MZ B cells compared with B6, with similar CD9 expression. Poor IgG3 switching by 129/Sv B cells is specific to CD23(high) follicular B cells, whereas similar changes in IgA switching are seen in both CD21(high) and CD23(high) B cell subsets from 129/Sv. Therefore, the functions and phenotypes of mature B cells differ among three common strains of mice.
用于基因操作研究的近交系小鼠品系在许多方面存在差异，包括免疫系统功能。除非小鼠经过充分回交，否则这些差异可能会干扰数据解读。在此，我们发现，与C57BL/6（B6）小鼠相比，瑞士詹姆斯·兰伯特（SJL）小鼠和129/Sv小鼠培养的脾B细胞向IgG3的抗体类别转换效率低2至6倍。在最佳刺激条件下，SJL和129/Sv B细胞的IgA转换也低2至19倍。与B6小鼠相比，SJL小鼠的脾B细胞表达更高水平的CD19和CD21，其CD21(高)CD23(低) B细胞几乎没有CD9表达，提示为非典型边缘区（MZ）B细胞。然而，脾B细胞亚群的分选纯化并未使SJL和B6之间向IgG3或IgA的体外类别转换达到平衡。与B6相比，129/Sv脾脏的MZ B细胞数量多3倍，CD9表达相似。129/Sv B细胞的IgG3转换不佳是CD23(高)滤泡B细胞所特有的，而在129/Sv的CD21(高)和CD23(高) B细胞亚群中均观察到IgA转换的类似变化。因此，三种常见小鼠品系的成熟B细胞功能和表型存在差异。
