CD47-mediated immune evasion in early-stage lung cancer progression.

Alveolar and interstitial macrophages play crucial roles in eradicating pathogens and transformed cells in the lungs. The immune checkpoint CD47, found on normal and malignant cells, interacts with the SIRPα ligand on macrophages, inhibiting phagocytosis, antigen presentation, and promoting immune evasion. In this study, we demonstrated that CD47 is not only a transmembrane protein, but that it is also highly concentrated in extracellular vesicles from lung cancer cell lines and patient plasma. Abundant CD47 was observed in the cytoplasm of lung cancer cells, aligning with our finding that it was packed into extracellular vesicles for physiological and pathological functions. In our clinical cohort, extracellular vesicle CD47 was significantly higher in the patients with early-stage lung cancer, emphasizing innate immunity inactivation in early tumor progression. To validate our hypothesis, we established an orthotopic xenograft model mimicking lung cancer development, which showed increased serum soluble CD47 and elevated IL-10/TNF-α ratio, indicating an immune-suppressive tumor microenvironment. CD47 expression led to reduced tumor-infiltrating macrophages during progression, while there was a post-xenograft increase in tumor-associated macrophages. In conclusion, CD47 is pivotal in early lung cancer progression, with soluble CD47 emerging as a key pathological effector.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Cheng-Hao Chuang reports financial support was provided by Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Tai-Huang Lee reports financial support was provided by Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. Chih-Jen Yang reports financial support was provided by National Science and Technology Council, Taiwan. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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