轉錄因子Hhex與共抑制因子Tle3協同促進記憶B細胞發育
作者:
小柯機器人發布時間:2020/6/30 21:27:01
美國加州大學舊金山分校Jason G. Cyster研究團隊發現,轉錄因子Hhex與共抑制因子Tle3協同促進記憶B細胞發育。該項研究成果於2020年6月29日在線發表在《自然—免疫學》上。
通過單細胞RNA測序分析,研究人員鑑定了分化為記憶B細胞(MBC)過程中的生發中心(GC)B細胞群體。使用一種可誘導的CRISPR–Cas9篩選方法,研究人員確定了造血表達的同源盒蛋白Hhex是調節MBC分化的轉錄因子。在篩選中還發現了共抑制因子Tle3,並且發現它與Hhex相互作用以促進MBC的發育。Bcl-6直接抑制GC B細胞中的Hhex。
相反,缺乏Hhex的MBC表現出Bcl6表達的增加和Bcl-6靶基因Bcl2表達的降低。Bcl-2的過表達能夠挽救Hhex缺陷細胞中的MBC分化。研究人員還確定了Ski是參與MBC分化的Hhex誘導型轉錄因子。這些發現表明,Hhex–Tle3在調控MBC分化的轉錄途徑中發揮了重要作用。
據悉,MBC對於長期的體液免疫至關重要。但是,涉及MBC分化的轉錄因子仍不清楚。
附:英文原文
Title: The transcription factor Hhex cooperates with the corepressor Tle3 to promote memory B cell development
Author: Brian J. Laidlaw, Lihui Duan, Ying Xu, Sara E. Vazquez, Jason G. Cyster
Issue&Volume: 2020-06-29
Abstract: Memory B cells (MBCs) are essential for long-lived humoral immunity. However, the transcription factors involved in MBC differentiation are poorly defined. Here, using single-cell RNA sequencing analysis, we identified a population of germinal center (GC) B cells in the process of differentiating into MBCs. Using an inducible CRISPR–Cas9 screening approach, we identified the hematopoietically expressed homeobox protein Hhex as a transcription factor regulating MBC differentiation. The corepressor Tle3 was also identified in the screen and was found to interact with Hhex to promote MBC development. Bcl-6 directly repressed Hhex in GC B cells. Reciprocally, Hhex-deficient MBCs exhibited increased Bcl6 expression and reduced expression of the Bcl-6 target gene Bcl2. Overexpression of Bcl-2 was able to rescue MBC differentiation in Hhex-deficient cells. We also identified Ski as an Hhex-induced transcription factor involved in MBC differentiation. These findings establish an important role for Hhex–Tle3 in regulating the transcriptional circuitry governing MBC differentiation.
DOI: 10.1038/s41590-020-0713-6
Source: https://www.nature.com/articles/s41590-020-0713-6