Biology subjects

Cools-Lartigue, J.

Publications and source records attributed to Cools-Lartigue, J..

6 recordsLinked to original sources

bioRxiv2026

Neutrophil Extracellular Trap Deposition Establishes an Immunosuppressive Environment in Non-metastatic Lymph Nodes and Facilitates Heterologous Metastatic Outgrowth

Metastasis accounts for most cancer-related mortality, and regional lymph nodes (LNs) are among the earliest sites of dissemination for many solid tumours. Yet tumour-draining lymph nodes (TDLNs) are also sites of adaptive immune activation, raising the question of how these immune organs become permissive to metastatic growth. We investigated whether neutrophil extracellular traps (NETs), which accumulate in TDLNs before detectable tumour-cell arrival, contribute to immune conditioning of histologically tumour-negative nodes and whether the consequences of this conditioning extend beyond the initiating tumour. Using multiplex immunofluorescence and spatial transcriptomic profiling of TDLNs from 19 patients with gastroesophageal adenocarcinoma, we found that NET positivity in non-metastatic TDLNs was associated with inferior overall survival and a distinct immunoregulatory state characterized by closer NET-Treg spatial relationships, coordinated increases in Treg-associated transcriptional programs, altered immune composition and redistribution of CD8 T cells away from Tregs. NET-positive nodes also showed reduced CD8 naive/stem-like transcription, while greater peri-Treg CD8 redistribution was associated with lower cytotoxic-effector transcription. In vitro, direct NET exposure shifted human T cells toward regulatory and dysfunction-associated phenotypes and impaired tumour-cell control. NET-conditioned Tregs further suppressed CD8 T cell proliferation and granzyme B expression, while depletion of Tregs attenuated NET-associated CD8 apoptosis. In tumour-bearing mice, neutrophil elastase inhibition altered activated Treg distribution across tumour-draining and contralateral LNs. Importantly, prior H59 tumour conditioning increased susceptibility to a subsequent heterologous MC38 metastatic challenge after removal of the initiating tumour; this phenotype was attenuated by TDLN resection and PAD4 deficiency. Adoptive transfer of contralateral-LN T cells from conditioned donors further identified a transferable component of this metastasis-permissive state that was sensitive to NET-directed intervention. These findings support a model in which NET-associated nodal immune conditioning alters Treg and CD8 T cell organization and function before overt nodal metastasis. The consequences of this conditioning extend beyond the draining node and can shape host susceptibility to a subsequent heterologous tumour challenge, broadening the premetastatic-niche concept toward conditioning of the host immune state.

cancer biology↗

bioRxiv2026

Novel retinoic acid receptor-related orphan receptor gamma inverse agonist enhances checkpoint blockade in hepatocellular carcinoma: a preclinical mouse study

Background and Aims: Neutrophil-associated inflammation is associated with poor outcomes in hepatocellular carcinoma (HCC), but tumour-intrinsic regulators of neutrophil recruitment and checkpoint response remain unclear. We evaluated whether inhibiting retinoic acid receptor-related orphan receptor gamma (RORgamma) alters neutrophil recruitment, programmed death-ligand 1 (PD-L1) expression, and response to PD-L1 blockade. Approach and Results: Survival associations were analysed in The Cancer Genome Atlas HCC cohort. Neutrophil migration toward HCC cells and PD-L1 expression were assessed after RORC silencing or TF-S10 treatment. Immunocompetent mice bearing orthotopic Hep-55.1c tumours received vehicle, TF-S10, anti-PD-L1, or combination treatment. Higher S100A9 and CXCL8 expression was associated with shorter survival (P = 0.000459 and P = 0.0004413, respectively), and tumour-bearing mice had higher neutrophil-to-lymphocyte ratios (P < 0.0001). RORgamma; targeting reduced neutrophil migration and intratumoural Ly6G; infiltration while increasing tumour-cell PD-L1 expression in vitro. Combination treatment reduced endpoint liver tumour volume versus anti-PD-L1 monotherapy (P < 0.01). Half of combination-treated mice had tumour volumes less than or equal to 0.10 cm^3 and none exceeded 1.00 cm^3, compared with 62% of controls exceeding 1.00 cm^3. Histologically, 85% of combination-treated mice had less than 10% liver tumour involvement, versus no controls. Combination treatment also reduced tumour-associated neutrophil populations and peripheral neutrophil-to-lymphocyte ratios. All active treatments reduced pulmonary metastatic burden versus controls, without significant differences among treatment groups; 53% of combination-treated mice had no detectable lung metastases. Conclusions: RORgamma inhibition reduces neutrophil recruitment and increases tumour-cell PD-L1 expression. Combined RORgamma inhibition and PD-L1 blockade improves hepatic tumour control in preclinical HCC and warrants further investigation.

cancer biology↗

bioRxiv2026

RORγ Inverse Agonism Redirects Tumour-Conditioned Emergency Myelopoiesis and Attenuates Established Tumour Progression

Systemic inflammation is associated with poor outcomes in gastroesophageal adenocarcinoma (GEA), but how it contributes to disease progression remains unclear. We investigated retinoic acid receptor-related orphan receptor gamma (ROR{gamma}) as a regulator of tumour-conditioned myeloid responses. In treatment-naive GEA patients, elevated circulating neutrophil-to-lymphocyte ratio (cNLR) tracked with circulating ROR{gamma} positive neutrophils and tumoural spatial organization of ROR{gamma} positive myeloid cells, rather than neutrophil abundance. In syngeneic tumour models, pharmacologic ROR{gamma} inverse agonism altered marrow progenitor composition before tumour-growth divergence and remodeled myeloid organization across bone marrow, tumour and lung despite no endpoint change in circulating neutrophil proportions, which did not capture the earlier marrow response or subsequent tumour trajectory. ROR{gamma} perturbation enhanced longitudinal tumour control with PD-L1 blockade, whereas effects on metastatic establishment depended on tumour conditioning and treatment timing. These findings identify ROR{gamma} associated myeloid programming as a therapeutically tractable, context-dependent regulator linking systemic inflammation, hematopoiesis, tissue immune organization, and cancer progression.

cancer biology↗

bioRxiv2026

A Measurable Systemic Immune Phenotype Links Circulating Myeloid Dysfunction to Tumour Spatial Organization in Gastroesophageal Adenocarcinoma

Background: Both static and longitudinal measures of circulating neutrophil-to-lymphocyte ratio (cNLR) are prognostic markers across solid malignancies, including gastroesophageal adenocarcinoma (GEA). Despite this consistency, cNLR remains poorly integrated into clinical decision-making and is generally regarded as a nonspecific inflammatory or disease-burden signal rather than a defined biological state. Analysis of a large, prospectively assembled GEA cohort showed that cNLR was only weakly associated with tumour burden or pathological response, yet both baseline and postoperative cNLR independently predicted outcome. Methods: These observations prompted a retrospective biological investigation of what host biology cNLR captures. Using available clinically linked biospecimens, we performed multiscale analyses across complementary patient subsets encompassing peripheral-blood immune function and soluble signalling, tumour single-cell transcriptional programmes, and spatial myeloid organization within tissue. Results: High baseline cNLR was associated with reduced circulating cytotoxic and immune-trafficking mediators, elevated angiogenesis-associated factors, neutrophil-mediated suppression of lymphocyte proliferation, impaired tumour-cell killing, and enhanced spontaneous neutrophil extracellular trap formation. Single-cell profiling identified coordinated transcriptional differences across tumour compartments, including innate, cytokine and myeloid programmes. Spatial profiling showed that myeloid abundance and organization varied across anatomical compartments; greater tumour-periphery PDL1 positive myeloid clustering was associated with inferior recurrence-free survival. Baseline cNLR showed little relationship with static myeloid abundance, whereas pretreatment cNLR dynamics were associated with altered cross-compartment spatial relationships between CD8 positive cells and myeloid cells. Notably, higher early postoperative cNLR was associated with greater PDL1 positive myeloid clustering at the tumour periphery, linking the spatial architecture of the resected tumour with a systemic myeloid phenotype persisting after surgery. Conclusions: The data identify a prognostic, multilevel myeloid-associated host phenotype in GEA that is incompletely explained by tumour burden. Integrating systemic immune function, tumour single cell transcriptomics and spatial myeloid organization demonstrates that these biological domains provide distinct, yet convergent views of the host immune phenotype captured by cNLR. These findings establish a biological framework for the clinical utility of cNLR and highlight myeloid-associated immune processes as promising targets for therapeutic intervention.

cancer biology↗

bioRxiv2023

Tumour Extracellular Vesicles Induce Neutrophil Extracellular Traps To Promote Lymph Node Metastasis

Lymph nodes (LNs) are frequently the first sites of metastasis. Currently, the only prognostic LN assessment is determining metastasis status. However, there is evidence suggesting that LN metastasis is facilitated by a pre-metastatic niche induced by tumour derived extracellular vehicles (EVs). Therefore, it is important to detect and modify the LN environmental changes. We have previously reported that neutrophil extracellular traps (NETs) can sequester and promote distant metastasis. Here, we first confirmed that LN NETs are associated with reduced patient survival. Next, we demonstrated that NETs deposition precedes LN metastasis and NETs inhibition abolishes LN metastases in animal mode. Furthermore, we discovered that EVs are essential to the formation of LN NETs. Lymphatic endothelial cells secrete CXCL8/2 in response to EVs inducing NETs formation and the promotion of LN metastasis. Our findings are the first to reveal the role of EV induced NETs in LN metastasis and provide potential immunotherapeutic vulnerabilities. Graphic AbstractIllustrative demonstration of the LNs premetastatic niche formation induced by EVs and NETs. Primary tumour constantly secretes EVs, which were actively uptaken by LECs. LECs subsequently secretes CXCL8 or CXCL2 upon EV reception. CXCL8 and CXCL2 are both neutrophil chemoattractants and potent NETs inducers. The following neutrophil recruitment and NETs formation lead to increased LN metastasis burden. O_FIG O_LINKSMALLFIG WIDTH=173 HEIGHT=200 SRC="FIGDIR/small/532413v2_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@c0c371org.highwire.dtl.DTLVardef@15f6a92org.highwire.dtl.DTLVardef@14dbeedorg.highwire.dtl.DTLVardef@131d3eb_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2021

Gram-negative bacterial infection increases lung cancer metastasis via Toll-like receptor 1 activation and increased cancer cell proliferation post-tumor adhesion

BackgroundLung cancer is a leading cause of death partially due to high recurrence rates after surgical resection. Clinical data suggest that post-operative infections may increase the risk of recurrence. Our previous work indicated that increased adhesion of circulating tumors in the context of infection is partially responsible for this phenotype. However, cancer metastasis is a multi-step process, and it is likely that other events following tumor adhesion also play a role. MethodsIn vivo intrasplenic injection of murine lung cancer cells into wild type (WT) and Toll-like receptor 4 knockout (TLR4-/-) mice followed by cecal-ligation and puncture (CLP) as a model of post-operative infection or sham surgery were used. H&E staining and immunohistochemistry analysis of Ki67+ cells in the livers of those mice were performed. In vitro proliferation assays were performed on human lung cancer cells using combinations of TLR blockade. ResultsWe found a 5-fold increase in hepatic metastases in WT CLP mice compared to WT sham mice. TLR4-/- CLP mice had a significant decreased tumor burden compared to WT CLP mice. This indicated an important mechanistic role for the TLR4-initiated host response to gram negative infection post-tumor cell adhesion. By analyzing the livers of those mice, we observed an increase in proliferation of tumor micrometastases in vivo in WT CLP mice as compared to WT sham mice. Here again, CLP TLR4 -/- mice had significantly fewer replicating micrometastases than CLP WT mice. Indeed, we found that direct stimulation of lung cancer cells with heat-inactivated E.Coli resulted in increased proliferation of tumor growth in vitro. These effects were partially abrogated by tumor TLR4 blockade; combined TLR2, 4 and 5 blockades led to a more prominent decrease. Conditioned media from bronchoalveolar epithelial cells treated with lipopolysaccharide lead to increased lung cancer proliferation; these changes were reversed with TLR blockade, indicating that the host response to infection is TLR mediated. ConclusionsOverall, these results imply a more complex mechanistic role of post-operative infection in metastasis. From a clinical standpoint, this evidence strengthens the case for the use of TLR blockade as a potential therapeutic target in the prevention of metastasis.

cancer biology↗