{
  "abstract": "Background STK11 loss in NSCLC is associated with immunotherapy resistance, and results in significant shifts in lineage plasticity. Here we link STK11-associated Multi-Lineage De-Differentiation (MLDD) phenotypes with distinct immune evasion mechanisms using computational approaches, and demonstrate functional significance of S100A8/A9 signaling within myeloid cells on immune suppression.Methods Transcriptional profiles corresponding to Multi-Lineage De-Differentiation (MLDD) phenotypes were evaluated across 567 STK11 deficient and 1551 STK11 WT NSCLC. Immune deconvolution with Cibersort and Xcell was performed, as well as pathway analysis using MsigDB. Patient outcomes for docetaxel and atezolizumab were assessed in OAK and POPLAR clinical trials. Single cell RNAseq analysis was performed using the Single-cell Lung Cancer Atlas. 1 We used spectral flow cytometry to characterize immune populations from syngeneic allografts of 8 KRAS-TP53 (KP) or KRAS -STK11-TP53 (KXP) GEMM cell lines. In a KXP line with high myeloid S100A8/A9 expression we then evaluated response to PD1/CTLA4 checkpoint blockade either alone or with S100A8/A9 inhibition using tasquinimod, with myeloid and T-cell antibody panels to interrogate the tumor immune microenvironment.Results Approximately two thirds of STK11-deficient tumors exhibit shifts in MLDD patterns. Immune deconvolution and pathway analysis demonstrates associations between lineage phenotypes and distinct patterns of immune evasion in the microenvironment. Neuroendocrine differentiation exhibited markedly reduced immune infiltration and inflammatory signaling, whereas loss of the TTF1 respiratory differentiation marker was linked to chronic ineffective inflammation, with dysfunctional CD8 T-cells and increased suppressive myeloid populations. High S100A8/A9 expression correlated with decreased dendritic cell infiltration, and T-cell dysfunction using both ‘bulk’ transcriptomic data and scRNAseq analysis. High S100A8/A9 expression was associated with poor response to atezolizumab in STK11-deficient tumors win OAK and POPLAR, but was not associated with outcomes in the STK11-WT tumors. In vivo, S100A8/A9 was expressed predominantly in CD11b+/Ly6g+ neutrophil populations and was highly correlated with CD4 and CD8 dysfunction, with a high percentage of lymphocytes exhibiting a naïve phenotype (CD44low/CD62Lhigh). After treatment with S100A8/A9 inhibitor tasquinimod, we observed a marked increase in CD4 and CD8 activation (figure 1) and depletion of Tregs and suppressive NK populations.Conclusions Our multiomic analysis demonstrates interactions between STK11 loss and lineage plasticity that significantly influence the immune microenvironment and response to PD1 checkpoint blockade. We highlight S100A8/9 as a key effector of suppressive myeloid cells in the context of STK11 loss, linking its expression to T-cell dysfunction in patient cohorts, scRNAseq analysis, and immunocompetent murine models, in which S100A8/A9 inhibition improves T-cell functionality.Reference Salcher S, Sturm G, Horvath L, et al. High-resolution single-cell atlas reveals diversity and plasticity of tissue-resident neutrophils in non-small cell lung cancer. Cancer Cell 2022;40:1503-1520.Abstract 706 Figure 1Naïve CD4 and CD8 T cell populations are markedly diminished using S100A8/A9 inhibitor Tasquinimod in combination with immune checkpoint blockade. Allografts of KRAS/TP53/STK11 mutant GEMM cell line were treated for 11 days with control, CTLA4/PD1, or CTLA4/PD1 with tasquinimod. Spectral flow cytometry was used to characterize T lymphocytes for A) CD8 cells and B) CD4 cells as indicated",
  "authors": [
    {
      "affiliations": [
        "Ohio State James Cancer Center, Columbus, OH, USA"
      ],
      "name": "Rahul Shivahare"
    },
    {
      "affiliations": [
        "Pelotonia Institute for Immuno-Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, 43210, USA., COLUMBUS, OH, USA"
      ],
      "name": "Jordan Krull"
    },
    {
      "affiliations": [
        "The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA"
      ],
      "name": "No Joon Song"
    },
    {
      "affiliations": [
        "Ohio State James Cancer Center, Columbus, OH, USA"
      ],
      "name": "Arezoo Salarpour"
    },
    {
      "affiliations": [
        "Ohio State James Cancer Center, Columbus, OH, USA"
      ],
      "name": "Jemal Imam"
    },
    {
      "affiliations": [
        "The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA"
      ],
      "name": "Ju Hwan Cho"
    },
    {
      "affiliations": [
        "Moffitt Cancer Center, Tampa, FL, USA"
      ],
      "name": "Douglas Cress"
    },
    {
      "affiliations": [
        "Moffitt Cancer Center, Tampa, FL, USA"
      ],
      "name": "Theresa Boyle"
    },
    {
      "affiliations": [
        "Pelotonia Institute for Immuno-Oncology, The Ohio State University Comprehensive Cancer Center, Columbus, OH, 43210, USA., COLUMBUS, OH, USA"
      ],
      "name": "Qin Ma"
    },
    {
      "affiliations": [
        "The Ohio State University, Columbus, OH, USA"
      ],
      "name": "Zihai Li"
    },
    {
      "affiliations": [
        "The Ohio State University Comprehensive Cancer Center, Columbus, OH, USA"
      ],
      "name": "David Paul Carbone"
    },
    {
      "affiliations": [
        "James Cancer Center Ohio State University, Columbus, OH, USA"
      ],
      "name": "Jacob Kaufman"
    }
  ],
  "title": "706 Lineage plasticity influences immune evasion through distinct mechanisms in STK11-deficient NSCLC, with myeloid S100A8/A9 pathway driving T-cell dysfunction in poorly differentiated TTF1-low tumors",
  "uid": "ee11924a-b0ab-5b64-b7cd-c56c6f5b3d09"
}