PTPN1/2 inhibits alveolar macrophage-mediated control of lung metastasis [CosMx SMI]

While therapeutic responses are influenced by organ-specific immune microenvironments, strategies to pharmacologically modulate these niches remain poorly defined. Here, using the clinical-stage inhibitor ABBV-CLS-484 (AC484) as a chemical probe, we demonstrate that systemic PTPN1/2 inhibition remodels the pulmonary myeloid landscape, specifically activating alveolar macrophages (AMs) toward a tumoricidal state.

Integrated single-cell/spatial transcriptomics and functional assays reveal that AC484 promotes AM accumulation within metastatic lesions, elevates their IFNγ production and responsiveness, and enhances their tumor-killing activity. Depletion of AMs diminishes the anti-metastatic efficacy of AC484. Mechanistically, inhibiting PTPN1/2 by AC484 amplifies IFNγ-STAT1 signaling in AMs, while disrupting this pathway impairs their tumor control capability.