ORIGINAL RESEARCH article

Front. Immunol.

Sec. Inflammation

Neonatal Pulmonary Vascular Remodeling Induced by Increased Blood Flow Is Associated with an Antiviral-like Immune Signature

  • 1. Shanghai Children's Medical Center, Shanghai, China

  • 2. Children's Hospital of Fudan University, Shanghai, China

  • 3. Ningbo Women and Children's Hospital, Ningbo, China

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Abstract

Background: Approximately 70% of pediatric pulmonary arterial hypertension (PAH) is associated with congenital heart disease causing increased pulmonary blood flow (IPF). The developing neonatal lung is highly susceptible to hemodynamic stress, yet the direct causal link and mechanisms of neonatal IPF-induced pulmonary vascular remodeling remain poorly understood due to the lack of suitable animal models that recapitulate this critical developmental window. Methods: We established a novel neonatal mouse model of IPF by performing an aortocaval fistula (ACF) on postnatal day 7(P7). Pulmonary hemodynamics were assessed by ultrasound at P30. Vascular remodeling was evaluated through histology (H&E, α-SMA immunofluorescence) and molecular analysis of phenotypic markers (Spp1, Myh11). Transcriptomic profiling (RNA-seq) and pathway enrichment analysis were employed to uncover underlying mechanisms, with flow cytometry and immunosuppression (Cyclosporin A) and type I interferon receptor blocker (MAR1-5A3) used for functional validation. Results: The neonatal ACF model successfully induced a left-to-right shunt, resulting in significant IPF and right ventricular volume overload. IPF mice exhibited pronounced pulmonary small vessel remodeling, evidenced by increased α-SMA intensity, elevated synthetic-phenotype marker (Spp1) expression, and decreased contractile-phenotype marker (Myh11). Transcriptomic analysis revealed a dominant immune signature, with the most enriched pathways being antiviral and interferon-response related ( response to virus and IL-17 signaling). This was corroborated by a significant increase in pulmonary CD4+ and CD8+ T cells. Crucially, immunosuppressive treatment and type I interferon receptor blocker attenuated vascular remodeling. Conclusions: We provide the direct experimental evidence that neonatal IPF alone is sufficient to drive pulmonary small vessel remodeling. The process is fundamentally mediated by an activated immune response characterized by an antiviral-like signature, a mechanism distinct from those reported in classic adult PAH models. This novel model offers a critical platform for investigating the developmental-specific pathogenesis of pediatric PAH and bridging the translational "valley of death."

Summary

Keywords

Increased pulmonary blood flow, Left-to-right shunt, Lung, neonatal animal models, Pulmonary vascular remodeling

Received

04 January 2026

Accepted

17 February 2026

Copyright

© 2026 Zheng, Li, Siqi, 薛, Li, Wang, Hu, Wang and Ye. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Jiapei Wang; Yuqing Hu; Jing Wang; Lincai Ye

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All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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