Analysis of Immune Memory Dynamics by visualizing memory B cell subsets

我们已经建立了一个新的小鼠系，其中激活的IgM+ B细胞被特异性标记，并可以诱导耗尽。M-SDV小鼠在IG重链Cmu基因座中具有loxP侧翼的STOP盒，随后是DTR-Venus表达构建体。如果Cre介导的重组发生，IgM+ B细胞应表达DTR-Venus融合蛋白。我们越过了M-SDV和AID-cre的界线。免疫后，一部分IgM+ B细胞变为DTR-Venus阳性，而IgM- B细胞保持DTR-Venus阴性。此外，当给小鼠施用DT时，DTR-Venus阳性细胞被完全删除。这些结果表明，M-SDV小鼠模型是检测或耗尽功能在很大程度上未知的IgM记忆B细胞的优良系统。

We have established a new mouse line in which activated IgM+ B cells are specifically labeled and can be inducibly depleted. The M-SDV mice have loxp-flanked STOP cassette followed by DTR-Venus expression construct in Ig heavy chain Cmu locus. If Cre-mediated recombination occurs, IgM+ B cells should express DTR-Venus fusion protein. We crossed M-SDV line with AID-cre. After immunization, a fraction of IgM+ B cells became DTR-Venus positive, while IgM- B cells remained DTR-Venus negative. Further, when the mice were administered with DT, the DTR-Venus positive cells were completely deleted. These results suggest that M-SDV mouse model is an excellent system to detect or deplete IgM memory B cells whose function is largely unknown.