Brorson K A, Krasnokutsky M V, Stein K E
Division of Monoclonal Antibodies, Food and Drug Administration, Bethesda, MD 20892, USA.
Mol Immunol. 1995 May;32(7):487-94. doi: 10.1016/0161-5890(95)00015-7.
Mice with the x-linked immunodeficiency mutation (xid) are unresponsive to polysaccharide antigens, lack a subset of B cells, and have low serum IgM (2-20% of normal) and IgG3 (3% of normal). Because of the disproportionate reduction of IgG3, the ability of B cells from xid mice to switch to gamma 3 was examined. Switching was indirectly measured by comparing IgG3 production and C gamma 3 mRNA steady state levels of purified B cells activated to switch to IgG3 by LPS in bulk culture. Direct measurement of switching was achieved by enumerating on a percentage basis switched cells in a filter disk culture assay and by FACS analysis. In both bulk culture and the filter disk assay, switching to gamma 3 was equivalent between xid and non-xid B cells.
具有X连锁免疫缺陷突变（xid）的小鼠对多糖抗原无反应，缺乏一部分B细胞，血清IgM水平低（为正常水平的2 - 20%），IgG3水平低（为正常水平的3%）。由于IgG3的不成比例降低，对xid小鼠B细胞转换为γ3的能力进行了检测。通过比较在批量培养中被LPS激活以转换为IgG3的纯化B细胞的IgG3产生量和Cγ3 mRNA稳态水平来间接测量转换。通过在滤盘培养试验中按百分比计数转换细胞并通过流式细胞术分析来直接测量转换。在批量培养和滤盘试验中，xid和非xid B细胞向γ3的转换是相同的。
