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The phenotype and wound healing property of IL‐4‐treated human macrophages is not affected by co‐treatment with antigen from the tapeworm, Hymenolepis diminuta
Author(s) -
Jayme Timothy Santiago,
Luis Jose,
Wang Arthur,
Thomson Emma T.,
Beck Paul,
McKay Derek
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.1045.1
Subject(s) - interleukin 4 , macrophage , wound healing , m2 macrophage , biology , immunology , inflammation , hymenolepis diminuta , microbiology and biotechnology , cytokine , helminths , cestoda , in vitro , biochemistry
Background Infection with parasitic helminths can reduce inflammation in animal models of colitis. A component of this anti‐inflammatory effect may be induction of alternatively‐activated IL‐4 driven anti‐inflammatory/pro‐resolution macrophages (M(IL4)) that have been implicated in wound repair. Infection with helminth parasites or exposure to worm extracts may elicit unique macrophage phenotypes. We hypothesized that macrophages co‐treated with IL‐4 and a crude extract Hymenolepis diminuta (HdE), would have an enhanced ability to promote repair in wounded epithelial monolayers. Aim To assess the impact of HdE on the development of human and murine M(IL4)s using canonical markers and assess the ability of these cells to promote epithelial wound repair. Methods Human (blood‐derived) and murine (bone marrow‐derived) macrophages were exposed to IL‐4 (10 ng/ml; 48h), HdE (100 mg/ml; 48h), IL4+HdE, or left unstimulated (controls). Expression of M(IL4) markers were assessed by qPCR, immunoblotting or ELISA (human: CD206, CCL18, CD14; murine: arginase‐1, Ym1). Confluent Caco2 epithelial cell monolayers were wounded with a razor blade and treated with supernatants from the different human macrophage sub‐types populations; protein denatured (trypsin‐treated + boiling) were also used. The total area of epithelial migration was measured (in mm 2 ) 24h later. TGFb levels in the macrophage supernatants were measured by ELISA. Results The development of human M(IL4)s was not affected by HdE co‐treatment as assessed by any of the markers examined, whereas HdE did reduce arginase‐1 and Ym1 in murine M(IL4)s (n=4–6). Supernatants from M(IL4)s increased epithelial migration by 36% ± 14% (n=8, p<0.05) compared to baseline, and this was not affected by HdE co‐treatment of the macrophages. Protein denaturing ablated the ability of M(IL4) supernatant to enhance epithelial wound repair (n=6). TGFb levels were increased in M(IL4) supernatants (353 ± 78*) compared to those from non‐stimulated macrophages (204 ± 71 pg/ml) (n=11; *p<0.05 (paired t test)). Conclusion HdE has negligible effects on the induction of a human M(IL4) and does not inhibit its ability to promote epithelial wound repair, that could be TGFb dependent. Thus, (1) M(IL4)s elicited in humans following infection with helminths will not be adversely affected by the release of worm antigen, and (2) if an anti‐colitic effect of systemic delivery of helminth antigens to humans results in mobilization of an IL‐4‐type alternatively activated macrophage, this would be an indirect effect of the worm antigen. Support or Funding Information Supported by Crohn's Colitis Canada grant to DMM and an NSERC CREATE Host‐Parasite Interactions scholarship to Timothy Jayme