Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 18 5 2026 10 05 807 817 Roohollah Zarei Koosha Applied Microbiology Research Center, Biomedicine Technologies Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran Raheleh Halabian Applied Microbiology Research Center, Biomedicine Technologies Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran Mahdi Fasihi-Ramandi Molecular Biology Research Center, Biomedicine Technologies Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran Abbas Ali Imani Fooladi Applied Microbiology Research Center, Biomedicine Technologies Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran 2025 11 05 2026 09 03 Background and Objectives: Pulmonary inflammation is central to the pathogenesis of various respiratory diseases, driving the need for novel therapeutics. Lipopolysaccharide (LPS) is a potent inflammatory trigger that induces proinflammatory cytokine synthesis via distinct signaling cascades. The objectives of this study were to evaluate the cytotoxic and anti-inflammatory effects of recombinant TGF-Arazyme fusion protein on LPS-stimulated human lung A549 and MRC-5 cell lines. Materials and Methods: A gene construct fusing Arazyme with a non-mitogenic TGFα fragment was expressed, purified via Ni-NTA chromatography, and validated enzymatically. Cytotoxicity was assessed by MTT assay. Inflammatory cytokine levels (TNF-α, IL-1β, IL-6, IL-10) were quantified by RT-PCR and ELISA. Anti-inflammatory efficacy was further validated in a murine (BALB/c) air pouch model infected with E. coli. Results: At 20 μg/mL, the chimeric protein showed no significant toxicity in MRC-5 cells but dose-dependently reduced A549 viability (p<0.01). Co-treatment with LPS and the chimeric protein significantly downregulated proinflammatory cytokines (TNF-α, IL-1β, IL-6) at both mRNA and protein levels (p<0.01, p<0.001), while increasing IL-10 (p<0.05). In the air pouch model, TGF-Arazyme reduced leukocyte counts by 48.3% (p<0.01), comparable to dexamethasone (51.2%). Conclusion: TGF-Arazyme exhibits both anti-inflammatory and selective cytotoxic properties, positioning it as a promising candidate for inflammatory lung diseases and lung cancer. https://ijm.tums.ac.ir/index.php/ijm/article/view/5909 https://ijm.tums.ac.ir/index.php/ijm/article/download/5909/1941