University of Tehran Iranian Journal of Veterinary Medicine 2251-8894 20 1 2026 01 01 Characterization of Serum Concentration of CD8, CD4, Interfron-γ, and Interleukin-4 in 4T1 Tumor Inoculated Mouse Model 35 42 101876 10.32598/ijvm.20.1.1005605 EN Ghazale Vazifehdoust Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Shahram Jamshidi Department of Internal Medicine, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Gholamreza Nikbakht Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mohammad Taheri Dr. Rastegar Laboratories, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Mahya Lalepoor Department of Pathology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran. Journal Article 2024 06 30 <strong>Background</strong>: Malignancies in domesticated animals, including cats and dogs, present significant health challenges. The 4T1 tumor-inoculated mouse model is pivotal for studying tumor biology and therapeutic strategies.<br /><strong>Objectives</strong>: This study aimed to characterize immune system alterations in the 4T1 tumor-inoculated mouse model by assessing serum concentrations of CD4 and CD8 antigens, along with cytokines interferon (IFN)-γ and interleukin (IL)-4.<br /><strong>Methods</strong>: BALB/c female mice were subcutaneously inoculated with 4T1 cells. Serum levels of CD4, CD8, IFN-γ, and IL-4 were quantified using ELISA, and histopathological analysis was performed to confirm tumorgenesis.<br /><strong>Results</strong>: Tumor-bearing mice exhibited significantly elevated CD8 levels (mean: 7.2613 ng/mL) compared to healthy controls (mean: 1.9749 ng/mL), whereas CD4 levels were lower in tumor-bearing mice (mean: 2.7632 ng/mL) compared to controls (mean: 4.8677 ng/mL). IFN-γ levels were reduced (mean: 10.95238 vs 22.85714 pg/mL), while IL-4 levels were increased (mean: 27.76942 vs 10.85452 pg/mL).<br /><strong>Conclusion</strong>: The 4T1 tumor model induces significant immune alterations, highlighting its utility for studying tumor immune evasion mechanisms and advancing immunotherapy strategies. https://ijvm.ut.ac.ir/article_101876_0ec31150b248f4b49c727f7b64e99d11.pdf