Disruption of the ATAD3A-VDAC1 complex to enhance anti-tumor immunity and response to immune checkpoint blockade in lung adenocarcinoma.

e20623 Background: Elucidating the role of mitochondrial function in anti-tumor immunity is crucial for improving the efficacy of immunotherapy. ATAD3A is a mitochondrial protein, but its mechanism of action in regulating tumor immunity remains unclear. This study aimed to investigate whether and how ATAD3A affects the response to immunotherapy in lung adenocarcinoma (LUAD). Methods: This study integrated clinical data analysis from multi-center LUAD patient cohorts, in vitro and in vivo gene-editing models, immune cell flow cytometry analysis, co-immunoprecipitation, protein domain mapping, and site-directed mutagenesis. Furthermore, a blocking peptide (0123–A1) was designed based on the structural mechanism, and its effects on anti-tumor immunity and immunotherapy efficacy were evaluated in cell lines and mouse xenograft models. Results: Clinical data analysis revealed that low ATAD3A expression was significantly associated with improved prognosis in LUAD patients following treatment with immune checkpoint inhibitors (ICIs). Mechanistically, the deletion of ATAD3A in cancer cells promoted the infiltration of anti-tumor CD274⁺ macrophages characterized by strong phagocytic capacity and potential for CD8⁺ T cell activation. ATAD3A directly binds to the 100-200 amino acid region of the VDAC1 protein, inhibiting its oligomerization and subsequent release of mitochondrial DNA into the cytosol. A key site mutation (D73A) completely abolished this interaction. The designed blocking peptide 0123–A1, based on this mechanism, effectively disrupted the ATAD3A-VDAC1 complex, significantly enhancing anti-tumor immune responses and improving the efficacy of immunotherapy both in vitro and in vivo. Conclusions: This study identifies ATAD3A as a key mitochondrial immune regulator in LUAD, which impairs anti-tumor immunity by binding to and inhibiting VDAC1 function. Strategies targeting the disruption of the ATAD3A-VDAC1 interaction can effectively reshape the tumor immune microenvironment and enhance the response to immunotherapy. This provides a novel potential therapeutic target and combination strategy for LUAD patients.