Peking University Yicheng and collaborators develop a new base editor Td-CBE

On November 11, 2022, the Yichengji research group and collaborators of the School of Life Sciences of Peking University jointly published the research results entitled "Re-engineering the adenine deaminase TadA-8e for efficient and specific CRISPR-based cytosine base editing" online in the journal Nature Biotechnology
。 This study successfully transformed TdA-8e adenine deaminase into a specific and efficient cytosine deaminase by introducing N46L mutations into it, and developed novel base editors Td-CGBE and Td-CBEs
based on this.

Screenshot of the article

Compared with the traditional CGBE/CBE base editor based on the AID/APOBEC family, the Td-CGBE/CBEs editor exhibits narrower editing window and lower editing characteristics such as insertion and deletion of by-products under the condition of similar editing activity
.
At the same time, the previously developed genome-wide, non-biased off-target detection technology Detect-seq was used to evaluate the Td-CBEs editor off-target
.
The evaluation found that Td-CBEs caused far fewer off-target sites at the genome-wide level than traditional CBEs with the same editing activity.
Although Td-CBEs are built on different deaminases than conventional base editor BE4max, Td-CBEs do not generate new off-target sites compared to BE4max
.
It is worth noting that Td-CBEs also do not produce the two new types of off-target edits (out-of-protospacer edits and target-strand edits)
that the previous research group found.

Detect-seq technology was used to detect and evaluate Td-CBEs off-target

The above results show that Td-CBEs is a safer base editor than traditional CBEs, which brings greater possibilities
for gene therapy of genetic diseases in the future.
At the same time, as a platform technology, Detect-seq can provide strong support and assistance
for the development of safer and more efficient gene editing tools.

Professor Yi Chengqi and Professor Li Dali and Professor Liu Mingyao of East China Normal University are the corresponding authors
of this paper.
Chen Liang, Zhu Biyun and Ru Gaomeng, graduate students of the School of Life Sciences, East China Normal University, as well as Meng Haowei, a postdoctoral fellow at the School of Life Sciences, Peking University, and Yan Yongchang, a doctoral student, are co-first authors
of this paper.
Dr.
Lei Zhixin and doctoral student Wu Hao of Peking University have made important contributions
to this research.
This work was supported
by the Key Research and Development Program of the Ministry of Science and Technology and the National Natural Science Foundation of China.
Peking University High Performance Computing Platform, School of Life Sciences Instrument Center and Phoenix Engineering have provided important technical support
for this project.