Trichinella spiralis – induced modulation of IFN-g and TGF-β shapes host immunity to support chronic infection … Original Research Article … |
The Egyptian Journal of Immunology E-ISSN (2090-2506) Volume 33 (2), April, 2026 Pages: 01–13. www.Ejimmunology.org https://doi.org/10.55133/eji.330201 |
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| A’laa F. A. Elsaid1, Ibrahim R. Shalash2, Mona M. El-Derbawy1, Mohammed S. El Faramawy3 and Tarek K. Zaalouk3 |
| 1Department of Medical Parasitology, Faculty of Medicine, Al-Azhar University, Damietta, Egypt.
2Department of Medical Parasitology, Theodor Bilharz Research Institute, Giza, Egypt. 3Department of Medical Parasitology Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
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Corresponding author: Tarek K. Zaalouk, Department of Medical Parasitology Faculty of Medicine, Al-Azhar University, Cairo, Egypt. Email: tkzaalouk@gmail.com |
Abstract
Trichinella spiralis is a widely prevalent foodborne helminth that establishes chronic infection through modulation of host immunity. This study investigated the temporal dynamics of interferon- g (IFN- g), transforming growth factor-β (TGF-β), and intestinal TGF-β receptor II expression during experimental T. spiralis infection and examined their relationship to parasite burden and tissue pathology. The study included 40 Swiss albino mice, orally infected with 250–300 larvae and sacrificed at 3, 7, 14 and 28 days post-infection (dpi). Adult worms and muscle larvae were quantified, serum cytokines were measured by an enzyme-linked immunosorbent assay, and intestinal TGF-β receptor II expression was evaluated immunohistochemically. Histopathological changes in intestinal and muscle tissues were assessed using hematoxylin and eosin staining. Adult worm burden peaked at 7 dpi (300.19 ± 25.8) and declined sharply thereafter, with complete clearance by 28 dpi. Muscle larvae accumulated progressively, reaching approximately 1 × 10⁴ larvae/mouse at 28 dpi. IFN- g levels rose significantly during the early intestinal phase, peaking at 7 dpi, and then declined toward baseline by 28 dpi. In contrast, TGF-β increased steadily throughout infection, and remained markedly elevated during the muscle phase. A significant negative correlation was observed between IFN-g and TGF-β (r = −0.42, p=0.012). TGF-β receptor II expression in the intestine was significantly up-regulated at 3–14 dpi and declined by 28 dpi. Histopathology revealed pronounced intestinal inflammation at 7–14 dpi with near-complete mucosal restoration by 28 dpi, while skeletal muscle displayed characteristic nurse cell–larva complexes. These findings demonstrated a coordinated shift from early IFN- g –mediated inflammation to sustained TGF-β–driven regulation, supporting parasite persistence and limiting tissue injury.
Keywords:
Trichinella spiralis; Interferon- g; TGF-β; Immune modulation; Immunopathology; Chronic infection.
Date received:15 December 2025; accepted: 05 March 2026
PMID:
41966500
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