Brief Article
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Nov 21, 2013; 19(43): 7766-7771
Published online Nov 21, 2013. doi: 10.3748/wjg.v19.i43.7766
PU.1-silenced dendritic cells prolong allograft survival in rats receiving intestinal transplantation
Xing-Wei Xu, Bo-Wen Ding, Chuan-Rong Zhu, Wu Ji, Jie-Shou Li
Xing-Wei Xu, Chuan-Rong Zhu, Wu Ji, Jie-Shou Li, Jinling Hospital, Research Institute of General Surgery, Nanjing University, School of Medicine, Nanjing 210002, Jiangsu Province, China
Bo-Wen Ding, Department of General Surgery, Xuzhou Hospital of Traditional Chinese Medicine, Xuzhou 221001, Jiangsu Province, China
Author contributions: Ji W designed the research and analyzed the data; Xu XW performed the research, analyzed the data and wrote the paper; Ding BW and Zhu CR performed the research; and Li JS guided and supervised the research.
Supported by A grant from the Natural Science Foundation of Jiangsu Province, China, No. BK2008237
Correspondence to: Wu Ji, MD, Professor, Jinling Hospital, Research Institute of General Surgery, Nanjing University, School of Medicine, No.305, East Zhongshan Road, Xuanwu District, Nanjing 210002, Jiangsu Province, China. jiwusky@126.com
Telephone: +86-25-80863334 Fax: +86-25-80863334
Received: July 20, 2013
Revised: September 5, 2013
Accepted: September 29, 2013
Published online: November 21, 2013
Processing time: 150 Days and 11.3 Hours
Abstract

AIM: To investigate the function of PU.1-silenced semi-mature dendritic cells (DCs) and the possibility of utilizing cell immunity in rat intestinal transplantation.

METHODS: DCs were isolated from the bone marrow of F344 rats and cultured using the adherent method. The PU.1 gene was knocked down in DCs using small interfering RNAs (siRNAs) for 24 h, and the cells were then incubated with lipopolysaccharide for 48 h. The PU.1 siRNA that had the highest silencing efficiency was screened using reverse transcription-polymerase chain reaction and Western blot for further study. The tolerance capacity was analyzed and compared between PU.1-silenced DCs (siRNA PU.1 group), negative control-silenced DCs (siRNA NC group) and immature DCs (control group) both in vitro and in vivo.

RESULTS: Blocking expression of the PU.1 gene in vitro led to a reduction in DC maturation and an increased tolerance capability. PU.1-silenced DCs expressed moderate levels of major histocompatibility complex (MHC)-II and low levels of co-stimulatory molecules, and produced more interleukin (IL)-10, but less IL-12. Compared with the negative control group, surface molecules cluster of differentiation 80 (CD80), CD86 and MHC-II in the siRNA PU.1 group were 27.0% ± 5.6%, 23.6% ± 4.8% and 36.8% ± 6.8%, respectively, and showed a significantly lower trend (P < 0.05). In vivo treatment of recipients with PU.1-silenced DCs injected before intestinal transplantation (siRNA PU.1 group), significantly prolonged allograft survival and resulted in better tissue histopathology compared with the siRNA NC group and control group. Mean survival time after transplantation was 14.3 ± 3.3 d in the siRNA PU.1 group (P < 0.05).

CONCLUSION: PU.1-silenced semi-mature DCs induced partial immune tolerance both in vitro and in vivo, which could be used as a new strategy to promote transplantation tolerance.

Keywords: Dendritic cell; PU.1; Tolerance; Intestinal transplantation; Immune tolerance

Core tip: The inhibition of dendritic cells (DCs) maturation can promote their tolerogenicity in transplantation. PU.1 is a newly discovered transcription factor which is required for the regulation of dendritic cell maturation in all DCs subsets. We silenced the PU.1 gene using siRNA and showed, for the first time, that PU.1-silenced DCs had immune tolerance. This may be a new strategy to prevent graft rejection following intestinal transplantation.