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Updated: Aug 21, 2025

An IL-8 Transiently Transgenized Mouse Model for the In Vivo Long-term Monitoring of Inflammatory Responses
Published on: July 7, 2017
Targeted Interleukin-9 delivery in pulmonary hypertension: Comparison of immunocytokine formats and effector cell
Judith Heiss1,2, Katja Grün1, Laura Tempel1
1Department of Internal Medicine I, University Hospital Jena, Jena, Germany.
Aims:
Pulmonary hypertension (PH) is accompanied by pulmonary vascular remodelling. By targeted delivery of Interleukin-9 (IL9) via the immunocytokine F8IL9, beneficial effects could be demonstrated in a mouse model of PH. This study aimed to compare two immunocytokine formats (single-chain Fv and full IgG) and to identify potential target cells of IL9.
Methods:
The Monocrotaline mouse model of PH (PH, n = 12) was chosen to evaluate the treatment effects of F8IL9F8 (n = 12) and F8IgGIL9 (n = 6) compared with sham-induced animals (control, n = 10), the dual endothelin receptor antagonist Macitentan (MAC, n = 12) or IL9-based immunocytokines with irrelevant antigen specificity (KSFIL9KSF, n = 12; KSFIgGIL9 n = 6). Besides comparative validation of treatment effects, the study was focused on the detection and quantification of mast cells (MCs) and regulatory T cells (Tregs).
Results:
There was a significantly elevated systolic right ventricular pressure (104 ± 36 vs. 45 ± 17 mmHg) and an impairment of right ventricular echocardiographic parameters (RVbasal: 2.52 ± 0.25 vs. 1.94 ± 0.13 mm) in untreated PH compared with controls (p < 0.05). Only the groups treated with F8IL9, irrespective of the format, showed consistent beneficial effects (p < 0.05). Moreover, F8IL9F8 but not F8IgGIL9 treatment significantly reduced lung tissue damage compared with untreated PH mice (p < 0.05). There was a significant increase in Tregs in F8IL9-treated compared with control animals, the untreated PH and the MAC group (p < 0.05).
Conclusions:
Beneficial treatment effects of targeted IL9 delivery in a preclinical model of PH could be convincingly validated. IL9-mediated recruitment of Tregs into lung tissue might play a crucial role in the induction of anti-inflammatory and anti-proliferative mechanisms potentially contributing to a novel disease-modifying concept.

