Early apoptosis leads to decrease of B cells in MRL/lpr mice / 中国免疫学杂志

ABSTRACT

Objective:To explore the change of B cell numbers in active MRL/lpr lupus mice , and their regulation mechanisms.Methods:B cell cycle and the percent of B cells in spleen lymphocytes of active MRL /lpr lupus mice and normal C 57/B6 mice were analyzed by using flow cytometry .The apoptotic B cells and their subclass were analyzed by Annexin V and PI staining.Further more ,B cells were purified by magnetic sorting , and real-time quantitative PCR was carried out to detect apoptosis-related gene.Results:Compared with the C57/B6 mice,the percent of B cells in active MRL/lpr lupus mice were significantly reduced (P<0.01),while the percent of apoptotic cells were significantly increased (P<0.01).The percent of early apoptotic B cells were sig-nificantly increased ( P <0.01 ) which including the immature and mature B cells , while the late apoptotic B cells were unchanged.Further more,we found that the anti-apoptotic protein BIRC3 was significantly reduced in active lupus B cells (P<0.01), while the pro-apoptotic protein BCL2L1 and BBC3(PUMA) were significantly increased(P<0.01).Conclusion: B cells in active lupus mice were significantly reduced while early apoptotic B cells were increased , which may be attributed to the changed balance between the anti-apoptotic and pro-apoptotic proteins , suggesting the reduction of B cells in SLE patients may be related to their increased early apoptosis .