Graft IL-33 regulates infiltrating macrophages to protect against chronic rejection

Tengfang Li, Zhongqiang Zhang, Joe G. Bartolacci, Gaelen K. Dwyer, Quan Liu, Lisa R. Mathews, Murugesan Velayutham, Anna S. Roessing, Yoojin C. Lee, Helong Dai, Sruti Shiva, Martin H. Oberbarnscheidt, Jenna L. Dziki, Steven J. Mullet, Stacy G. Wendell, James D. Wilkinson, Steven A. Webber, Michelle Wood-Trageser, Simon C. Watkins, Anthony J. DemetrisGeorge S. Hussey, Stephen F. Badylak, Heth R. Turnquist*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

38 Scopus citations


Alarmins, sequestered self-molecules containing damage-associated molecular patterns, are released during tissue injury to drive innate immune cell proinflammatory responses. Whether endogenous negative regulators controlling early immune responses are also released at the site of injury is poorly understood. Herein, we establish that the stromal cell-derived alarmin interleukin 33 (IL-33) is a local factor that directly restricts the proinflammatory capacity of graft-infiltrating macrophages early after transplantation. By assessing heart transplant recipient samples and using a mouse heart transplant model, we establish that IL-33 is upregulated in allografts to limit chronic rejection. Mouse cardiac transplants lacking IL-33 displayed dramatically accelerated vascular occlusion and subsequent fibrosis, which was not due to altered systemic immune responses. Instead, a lack of graft IL-33 caused local augmentation of proinflammatory iNOS+ macrophages that accelerated graft loss. IL-33 facilitated a metabolic program in macrophages associated with reparative and regulatory functions, and local delivery of IL-33 prevented the chronic rejection of IL-33-deficient cardiac transplants. Therefore, IL-33 represents what we believe is a novel regulatory alarmin in transplantation that limits chronic rejection by restraining the local activation of proinflammatory macrophages. The local delivery of IL-33 in extracellular matrix-based materials may be a promising biologic for chronic rejection prophylaxis.

Original languageEnglish
Pages (from-to)5397-5412
Number of pages16
JournalJournal of Clinical Investigation
Issue number10
StatePublished - 1 Oct 2020
Externally publishedYes


Dive into the research topics of 'Graft IL-33 regulates infiltrating macrophages to protect against chronic rejection'. Together they form a unique fingerprint.

Cite this