The Presence of Interleukin-13 at Pancreatic ADM/PanIN Lesions Alters Macrophage Populations and Mediates Pancreatic Tumorigenesis

• Main Authors: Geou-Yarh Liou, Ligia Bastea, Alicia Fleming, Heike Döppler, Brandy H. Edenfield, David W. Dawson, Lizhi Zhang, Nabeel Bardeesy, Peter Storz
• Format: Article
• Language: English
• Published: Elsevier 2017-05-01
• Series: Cell Reports
• Subjects: pancreatic cancer; PanIN; metaplasia; Tuft cells; macrophages; polarization; IL-13; interleukin-13; CCL-2; IL-1ra
• Online Access: http://www.sciencedirect.com/science/article/pii/S2211124717305466

The contributions of the innate immune system to the development of pancreatic cancer are still ill defined. Inflammatory macrophages can initiate metaplasia of pancreatic acinar cells to a duct-like phenotype (acinar-to-ductal metaplasia [ADM]), which then gives rise to pancreatic intraepithelial neoplasia (PanIN) when oncogenic KRas is present. However, it remains unclear when and how this inflammatory macrophage population is replaced by tumor-promoting macrophages. Here, we demonstrate the presence of interleukin-13 (IL-13), which can convert inflammatory into Ym1+ alternatively activated macrophages, at ADM/PanIN lesions. We further show that Ym1+ macrophages release factors, such as IL-1ra and CCL2, to drive pancreatic fibrogenesis and tumorigenesis. Treatment of mice expressing oncogenic KRas under an acinar cell-specific promoter with a neutralizing antibody for IL-13 significantly decreased the accumulation of alternatively activated macrophages at these lesions, resulting in decreased fibrosis and lesion growth.