Fig. 2: Murine model of HNSCC with high G-CSF production (^GMOPC) is characterized by impaired neutrophil bactericidal responses.

a G-CSF concentrations in tumor-condensed medium from HNSCC patients (n = 20) and in plasma in murine oropharyngeal carcinoma models with low (MOPC) (n = 5 mice) or high (^GMOPC) G-CSF production (n = 8 mice) in comparison to tumor-free mice (n = 6). Samples of tumor-condensed medium from HNSCC patients with low (n = 10) and high (n = 10) G-CSF content were selected based on median levels in the cohort. b–f Mice were injected subcutaneously with PBS (control, Co), MOPC, or ^GMOPC cells. On day 14, Pseudomonas aeruginosa (10⁶ CFU) was inoculated intratracheally. After 18 h, animals were sacrificed, and BAL fluid and lung tissue were collected (gating strategy Fig. S3a). b Decreased clearance of P. aeruginosa from the lower respiratory tract in ^GMOPC-bearing mice (n = 14) in comparison to MOPC-bearing (n = 8) or tumor-free (n = 4) mice. c Representative image of lung tissue damage (haematoxylin–eosin, scale bar = 30 µm). d Reduced aerated lung area in ^GMOPC-bearing mice (n = 9) in comparison to MOPC-bearing (n = 6) or tumor-free (n = 8) mice. e Increased TNFα expression in lungs of ^GMOPC-bearing mice (n = 4) in comparison to MOPC-bearing (n = 4) or tumor-free (n = 4) mice. f Worse general clinical performance in ^GMOPC-bearing mice (n = 14) in comparison to MOPC-bearing (n = 8) mice. g, h Mice were injected subcutaneously with PBS, MOPC, or ^GMOPC cells. On day 14, animals were sacrificed, lungs were collected, and live Ly6G⁺ neutrophils were isolated. g ^GMOPC-bearing mice (n = 4) showed marked neutrophil infiltration in non-infected lungs in comparison to MOPC-bearing (n = 4) or tumor-free (n = 4) mice. h Lungs of ^GMOPC-bearing mice (n = 3) were enriched in CD62L^low CD11b^dim neutrophil subsets in comparison to lungs of MOPC-bearing (n = 3) or tumor-free (n = 3) mice. i–m Mice were injected subcutaneously with MOPC or ^GMOPC cells. On day 14, animals were sacrificed, lungs were collected, and live Ly6G⁺ neutrophils were isolated for proteomic profiling. i, j Lung neutrophils from ^GMOPC-bearing mice (orange) displayed a distinct proteomic signature compared with the MOPC group (blue) (n = 5 mice in each group). k–m Gene Ontology (GO) enrichment analysis of upregulated (orange) and downregulated (blue) pathways in ^GMOPC lung neutrophils: k biological processes; l cellular components; m molecular functions. HNSCC head and neck squamous cell carcinoma, Co control tumor-free mice, MOPC mice bearing non-G-CSF-producing tumors, ^GMOPC mice bearing G-CSF-producing tumors, BAL bronchoalveolar lavage, TNFα tumor necrosis factor-α, CFU colony-forming units. Data are presented as means with individual values (biological replicates) shown. Statistical tests: χ2 (f); Kruskal–Wallis for multiple-group comparisons with Bonferroni correction, two-sided Mann–Whitney for two-group comparisons (a, b, d, e, g). *p  <  0.05, **p < 0.01, ***p < 0.001. Source data and exact p-values are provided as a Source Data file.