{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T21:48:50Z","timestamp":1785793730763,"version":"3.56.0"},"posted":{"date-parts":[[2026,7,31]]},"group-title":"Cancer Biology","reference-count":43,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T00:00:00Z","timestamp":1785456000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"National Cancer Institute","award":["ZIA BC 011793"],"award-info":[{"award-number":["ZIA BC 011793"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,7,31]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Purpose<\/jats:title>\n                  <jats:p>Liver metastases confer poor outcomes and attenuate the benefit of immunotherapy across solid tumors. This study investigated how the hepatic metastatic niche promotes CD8\u207a T cell dysfunction and immunotherapy resistance in small-cell lung cancer (SCLC).<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Experimental Design<\/jats:title>\n                  <jats:p>Clinical outcomes and tumor gene expression were integrated with multi-region single-cell RNA sequencing of T cells from rapid-autopsy SCLC metastases, together with spatial transcriptomics. SCLC-hepatocyte conditioned-media models were combined with stable-isotope tracing, mass spectrometry, functional and metabolic assays, and ChIP-qPCR to define mechanisms of CD8\u207a T cell suppression.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>\n                    Liver metastases were associated with inferior survival and reduced benefit from immune checkpoint blockade. Multi-region single-cell analysis showed that CD8\u207a T cells from liver metastases exhibited an exhaustion-associated state enriched for hypoxia, lactate, and TGF-\u03b2 programs. SCLC-hepatocyte crosstalk generated a lactate- and TGF-\u03b2-rich microenvironment that reduced CD8\u207a T cell effector function, proximal T cell receptor signaling, glycolytic fitness, viability, and proliferation. Stable-isotope tracing demonstrated transfer and accumulation of co-culture-derived lactate in recipient CD8\u207a T cells, with limited entry into downstream pyruvate-linked pathways. Lactate accumulation was accompanied by increased H3K18 lactylation at the\n                    <jats:italic>PDCD1<\/jats:italic>\n                    ,\n                    <jats:italic>LAG3<\/jats:italic>\n                    , and\n                    <jats:italic>TGFB1<\/jats:italic>\n                    regulatory loci. In parallel, SCLC-hepatocyte crosstalk increased paracrine TGF-\u03b2 and activated canonical SMAD2 signaling in CD8\u207a T cells. TGF-\u03b2 receptor inhibition restored CD8\u207a T cell proliferation. In the phase III IMpower133 cohort, a combined lactate-TGF-\u03b2 transcriptional program was associated with inferior survival, most strongly in patients with liver metastases.\n                  <\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Tumor-hepatocyte crosstalk generates convergent lactate and TGF-\u03b2 signals that drive CD8\u207a T cell dysfunction in liver metastases. This hepatic immune-metabolic circuit provides a potential mechanism for immunotherapy resistance and supports therapeutic strategies targeting TGF-\u03b2 signaling in liver-metastatic SCLC.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Translational Relevance<\/jats:title>\n                  <jats:p>Patients with SCLC liver metastases have poor outcomes and derive limited benefit from immune checkpoint blockade, but actionable mechanisms of hepatic immune resistance remain undefined. We identify an immune-metabolic circuit in which SCLC\u2013hepatocyte crosstalk generate lactate and TGF-\u03b2 signals that converge on CD8\u207a T cells. Stable-isotope tracing demonstrates the transfer and accumulation of tumor\u2013hepatocyte-derived lactate in recipient T cells, which causes H3K18 lactylation at exhaustion- and TGFB1-associated loci. In parallel, paracrine TGF-\u03b2 activates canonical SMAD signaling and reinforces proliferative dysfunction. TGF-\u03b2 receptor inhibition restores CD8\u207a T cell proliferation. In the phase III IMpower133 cohort, a combined lactate\u2013TGF-\u03b2 program is associated with inferior survival, particularly among patients with liver metastases. These findings provide a mechanistic and biomarker framework for testing TGF-\u03b2-directed strategies in liver-metastatic SCLC, a population with substantial unmet clinical need.<\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.07.30.741857","type":"posted-content","created":{"date-parts":[[2026,7,31]],"date-time":"2026-07-31T14:40:11Z","timestamp":1785508811000},"source":"Crossref","is-referenced-by-count":0,"title":["Tumor-hepatocyte crosstalk drives a hepatic lactate-TGF-\u03b2 axis of CD8\n                  <sup>+<\/sup>\n                  T cell exhaustion and immunotherapy resistance in small-cell lung cancer liver metastases"],"prefix":"10.64898","author":[{"given":"Amira","family":"Kazi","sequence":"first","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yingying","family":"Cao","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5825-3356","authenticated-orcid":false,"given":"Chirayu","family":"Mohindroo","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1417-6918","authenticated-orcid":false,"given":"Abhinav","family":"Joshi","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yue","family":"Huang","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9022-8700","authenticated-orcid":false,"given":"Chiori","family":"Tabe","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6019-2022","authenticated-orcid":false,"given":"Brett","family":"Schroeder","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9545-2450","authenticated-orcid":false,"given":"Thorkell","family":"Andersson","sequence":"additional","affiliation":[{"name":"Protein Characterization Laboratory, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4811-7342","authenticated-orcid":false,"given":"Ajit Kumar","family":"Sharma","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3293-3115","authenticated-orcid":false,"given":"Anish","family":"Thomas","sequence":"additional","affiliation":[{"name":"Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026080314401934000_2026.07.30.741857v1.1","doi-asserted-by":"publisher","DOI":"10.1038\/s41591-020-1131-x"},{"key":"2026080314401934000_2026.07.30.741857v1.2","doi-asserted-by":"publisher","DOI":"10.1158\/1078-0432.Ccr-21-1193"},{"key":"2026080314401934000_2026.07.30.741857v1.3","doi-asserted-by":"publisher","DOI":"10.1007\/s10585-023-10217-7"},{"key":"2026080314401934000_2026.07.30.741857v1.4","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2019.02525"},{"key":"2026080314401934000_2026.07.30.741857v1.5","doi-asserted-by":"publisher","DOI":"10.1002\/hep.27254"},{"key":"2026080314401934000_2026.07.30.741857v1.6","doi-asserted-by":"publisher","DOI":"10.1038\/s41571-022-00689-z"},{"key":"2026080314401934000_2026.07.30.741857v1.7","doi-asserted-by":"publisher","DOI":"10.1038\/nri3862"},{"key":"2026080314401934000_2026.07.30.741857v1.8","doi-asserted-by":"publisher","DOI":"10.1016\/j.immuni.2016.07.009"},{"key":"2026080314401934000_2026.07.30.741857v1.9","doi-asserted-by":"publisher","DOI":"10.1016\/j.immuni.2022.12.008"},{"key":"2026080314401934000_2026.07.30.741857v1.10","doi-asserted-by":"publisher","DOI":"10.1182\/blood-2006-07-035972"},{"key":"2026080314401934000_2026.07.30.741857v1.11","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmet.2016.08.011"},{"key":"2026080314401934000_2026.07.30.741857v1.12","doi-asserted-by":"publisher","DOI":"10.1007\/s00262-009-0692-9"},{"key":"2026080314401934000_2026.07.30.741857v1.13","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-017-01427-1"},{"key":"2026080314401934000_2026.07.30.741857v1.14","doi-asserted-by":"publisher","DOI":"10.1038\/s43018-025-00996-1"},{"key":"2026080314401934000_2026.07.30.741857v1.15","doi-asserted-by":"publisher","DOI":"10.1038\/s41572-020-00235-0"},{"key":"2026080314401934000_2026.07.30.741857v1.16","doi-asserted-by":"publisher","DOI":"10.1016\/j.chest.2018.07.029"},{"key":"2026080314401934000_2026.07.30.741857v1.17","doi-asserted-by":"publisher","DOI":"10.3892\/ol.2012.792"},{"key":"2026080314401934000_2026.07.30.741857v1.18","doi-asserted-by":"publisher","DOI":"10.1007\/s10555-024-10220-8"},{"key":"2026080314401934000_2026.07.30.741857v1.19","doi-asserted-by":"publisher","DOI":"10.2217\/fon-2017-0706"},{"key":"2026080314401934000_2026.07.30.741857v1.20","doi-asserted-by":"publisher","DOI":"10.1385\/MO:20:1:25"},{"key":"2026080314401934000_2026.07.30.741857v1.21","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(19)32222-6"},{"key":"2026080314401934000_2026.07.30.741857v1.22","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1809064"},{"key":"2026080314401934000_2026.07.30.741857v1.23","doi-asserted-by":"publisher","DOI":"10.1111\/j.1478-3231.2005.01017.x"},{"key":"2026080314401934000_2026.07.30.741857v1.24","doi-asserted-by":"publisher","DOI":"10.1038\/s41590-020-00834-9"},{"key":"2026080314401934000_2026.07.30.741857v1.25","doi-asserted-by":"publisher","DOI":"10.1038\/s41590-022-01229-8"},{"key":"2026080314401934000_2026.07.30.741857v1.26","doi-asserted-by":"publisher","DOI":"10.1172\/jci.insight.138970"},{"key":"2026080314401934000_2026.07.30.741857v1.27","doi-asserted-by":"publisher","DOI":"10.1016\/j.redox.2017.01.012"},{"key":"2026080314401934000_2026.07.30.741857v1.28","doi-asserted-by":"publisher","DOI":"10.1002\/hep.32408"},{"key":"2026080314401934000_2026.07.30.741857v1.29","doi-asserted-by":"publisher","DOI":"10.1016\/j.livres.2025.11.004"},{"key":"2026080314401934000_2026.07.30.741857v1.30","doi-asserted-by":"publisher","DOI":"10.3390\/cancers12113244"},{"key":"2026080314401934000_2026.07.30.741857v1.31","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20071641"},{"key":"2026080314401934000_2026.07.30.741857v1.32","doi-asserted-by":"publisher","DOI":"10.18632\/oncotarget.18251"},{"key":"2026080314401934000_2026.07.30.741857v1.33","doi-asserted-by":"publisher","DOI":"10.1016\/j.tibs.2017.11.008"},{"key":"2026080314401934000_2026.07.30.741857v1.34","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2013.05.016"},{"key":"2026080314401934000_2026.07.30.741857v1.35","doi-asserted-by":"publisher","DOI":"10.1002\/eji.200838289"},{"key":"2026080314401934000_2026.07.30.741857v1.36","doi-asserted-by":"publisher","DOI":"10.1038\/s41590-024-01999-3"},{"key":"2026080314401934000_2026.07.30.741857v1.37","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pbio.1002202"},{"key":"2026080314401934000_2026.07.30.741857v1.38","doi-asserted-by":"publisher","DOI":"10.1186\/s40170-022-00287-8"},{"key":"2026080314401934000_2026.07.30.741857v1.39","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmet.2016.01.007"},{"key":"2026080314401934000_2026.07.30.741857v1.40","doi-asserted-by":"publisher","DOI":"10.1016\/j.copbio.2015.02.003"},{"key":"2026080314401934000_2026.07.30.741857v1.41","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-019-1678-1"},{"key":"2026080314401934000_2026.07.30.741857v1.42","doi-asserted-by":"publisher","DOI":"10.1002\/ctm2.160"},{"key":"2026080314401934000_2026.07.30.741857v1.43","doi-asserted-by":"publisher","DOI":"10.1158\/2326-6066.CIR-16-0325"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.07.30.741857","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,3]],"date-time":"2026-08-03T21:40:33Z","timestamp":1785793233000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.07.30.741857"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,31]]},"references-count":43,"URL":"https:\/\/doi.org\/10.64898\/2026.07.30.741857","relation":{},"subject":[],"published":{"date-parts":[[2026,7,31]]},"subtype":"preprint"}}