{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:19:43Z","timestamp":1792790383714,"version":"4.5.0"},"posted":{"date-parts":[[2026,5,10]]},"group-title":"Microbiology","reference-count":51,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,5,10]],"date-time":"2026-05-10T00:00:00Z","timestamp":1778371200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"NIH\/NIAID","award":["R21AI194017"],"award-info":[{"award-number":["R21AI194017"]}]},{"name":"NIH\/NIAID","award":["R01AI141958"],"award-info":[{"award-number":["R01AI141958"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,5,10]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>\n                  Congenital syphilis is a leading cause of preventable stillbirth, yet the mechanisms that enable\n                  <jats:italic>Treponema pallidum<\/jats:italic>\n                  subsp.\n                  <jats:italic>pallidum,<\/jats:italic>\n                  the etiological agent of syphilis, to traverse and persist within the human placenta are virtually unknown. This knowledge gap reflects, in part, the fastidious nature of\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  , which has historically only been propagated in rabbit epithelial cells. Here, we demonstrate that\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  replicates and can be propagated long-term in human placental trophoblast models. We identified three human trophoblast cell lines, JEG-3, BeWo, and HTR-8, that sustained robust\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  replication for over 55 days. Confocal imaging with GFP-expressing\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  demonstrated bacterial adherence to trophoblast cultures. To identify human placental pathways that may support\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  replication and persistence, we performed bulk transcriptomic profiling of the three trophoblast lines co-cultured with\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  for 3 or 7 days. Our findings revealed conserved host responses involving increased cholesterol synthesis, suppressed type I interferon signaling, and disrupted extracellular matrix organization. These data implicate host metabolic rewiring, innate immune attenuation, and extracellular matrix remodeling as candidate pathways that may promote\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  invasion, replication and persistence within the placenta. Together, these models represent the first human placental systems capable of supporting efficient, long-term\n                  <jats:italic>T. pallidum<\/jats:italic>\n                  growth and provide a foundation for mechanistic studies of congenital syphilis pathogenesis.\n                <\/jats:p>","DOI":"10.64898\/2026.05.10.724106","type":"posted-content","created":{"date-parts":[[2026,5,11]],"date-time":"2026-05-11T05:05:16Z","timestamp":1778475916000},"source":"Crossref","is-referenced-by-count":2,"title":["Human placental trophoblasts support sustained\n                  <i>Treponema pallidum<\/i>\n                  replication and reveal new candidate host pathways implicated in congenital syphilis"],"prefix":"10.64898","author":[{"given":"Eliza R","family":"McColl","sequence":"first","affiliation":[{"name":"Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diane G","family":"Edmondson","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bridget D","family":"DeLay","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karan G","family":"Kaval","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven J","family":"Bark","sequence":"additional","affiliation":[{"name":"Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven J","family":"Norris","sequence":"additional","affiliation":[{"name":"Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center Houston, Houston, TX, USA;"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3917-8677","authenticated-orcid":false,"given":"Indira U","family":"Mysorekar","sequence":"additional","affiliation":[{"name":"Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA;"},{"name":"Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"key":"2026051305002175000_2026.05.10.724106v1.1","unstructured":"World Health Organization. Congenital syphilis - Mother-to-child transmission of syphilis. https:\/\/www.who.int\/teams\/global-hiv-hepatitis-and-stis-programmes\/stis\/prevention\/mother-to-child-transmission-of-syphilis."},{"key":"2026051305002175000_2026.05.10.724106v1.2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2025.17362"},{"key":"2026051305002175000_2026.05.10.724106v1.3","doi-asserted-by":"crossref","unstructured":"Plotzker, R. E. , Murphy, R. D. & Stoltey, J. E . Congenital Syphilis Prevention: Strategies, Evidence, and Future Directions. Sex Transm Dis 45, S29 (2018).","DOI":"10.1097\/OLQ.0000000000000846"},{"key":"2026051305002175000_2026.05.10.724106v1.4","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(23)00314-6"},{"key":"2026051305002175000_2026.05.10.724106v1.5","unstructured":"CDC. Sexually Transmitted Infections Surveillance, 2022. https:\/\/www.cdc.gov\/std\/statistics\/2022\/default.htm (2024)."},{"key":"2026051305002175000_2026.05.10.724106v1.6","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1080\/15513815.2018.1485798","article-title":"Fetal and Placental Pathology in Congenital Syphilis: A Comprehensive Study in Perinatal Autopsy","volume":"37","year":"2018","journal-title":"Fetal Pediatr Pathol"},{"key":"2026051305002175000_2026.05.10.724106v1.7","doi-asserted-by":"publisher","DOI":"10.1016\/S0029-7844(02)02010-0"},{"key":"2026051305002175000_2026.05.10.724106v1.8","doi-asserted-by":"publisher","DOI":"10.1016\/S0046-8177(96)90110-0"},{"key":"2026051305002175000_2026.05.10.724106v1.9","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1016\/0046-8177(93)90016-A","article-title":"Placental histopathology in syphilis","volume":"24","year":"1993","journal-title":"Hum Pathol"},{"key":"2026051305002175000_2026.05.10.724106v1.10","doi-asserted-by":"crossref","unstructured":"Li, W. , Yuan, W. , Huang, S. , Zou, L. , Zheng, K. & Xie, D . Research progress on the mechanism of Treponema pallidum breaking through placental barrier. Microbial Pathogenesis 185, 106392 (2023).","DOI":"10.1016\/j.micpath.2023.106392"},{"key":"2026051305002175000_2026.05.10.724106v1.11","first-page":"e01153","article-title":"Long-Term In Vitro Culture of the Syphilis Spirochete Treponema pallidum subsp. pallidum","volume":"9","year":"2018","journal-title":"mBio"},{"key":"2026051305002175000_2026.05.10.724106v1.12","doi-asserted-by":"crossref","unstructured":"Bos\u00e1k, J. , Hrala, M. , Posp\u00ed\u0161ilov\u00e1, P. , Bosakova, M. & \u0160majs, D . First human cell-based cultivation system for the syphilis spirochete Treponema pallidum. BMC Microbiol 26, (2026).","DOI":"10.1186\/s12866-026-04856-5"},{"key":"2026051305002175000_2026.05.10.724106v1.13","doi-asserted-by":"publisher","DOI":"10.1210\/jcem-32-5-683"},{"key":"2026051305002175000_2026.05.10.724106v1.14","doi-asserted-by":"publisher","DOI":"10.1126\/science.159.3822.1467"},{"key":"2026051305002175000_2026.05.10.724106v1.15","doi-asserted-by":"crossref","unstructured":"Dusza, H. M. , van Boxel, J. , van Duursen, M. B. M. , Forsberg, M. M. , Legler, J. & V\u00e4h\u00e4kangas, K. H . Experimental human placental models for studying uptake, transport and toxicity of micro- and nanoplastics. Science of The Total Environment 860, 160403 (2023).","DOI":"10.1016\/j.scitotenv.2022.160403"},{"key":"2026051305002175000_2026.05.10.724106v1.16","doi-asserted-by":"publisher","DOI":"10.1006\/excr.1993.1139"},{"key":"2026051305002175000_2026.05.10.724106v1.17","doi-asserted-by":"crossref","unstructured":"Sheridan, M. A. , Zhou, J. , Franz, A. W. E. & Schust, D. J . Modeling the Human Placenta to Investigate Viral Infections During Pregnancy. Front.Virol. 2, 831754 (2022).","DOI":"10.3389\/fviro.2022.831754"},{"key":"2026051305002175000_2026.05.10.724106v1.18","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.201105152"},{"key":"2026051305002175000_2026.05.10.724106v1.19","doi-asserted-by":"crossref","unstructured":"Silberstein, E. , Kim, K. S. , Acosta, D. & Debrabant, A . Human Placental Trophoblasts Are Resistant to Trypanosoma cruzi Infection in a 3D-Culture Model of the Maternal-Fetal Interface. Front. Microbiol. 12, (2021).","DOI":"10.3389\/fmicb.2021.626370"},{"key":"2026051305002175000_2026.05.10.724106v1.20","doi-asserted-by":"crossref","unstructured":"Costa, A. C. , Pinheiro, J. , Reis, S. A. , Cabanes, D. & Sousa, S . Listeria monocytogenes Interferes with Host Cell Mitosis through Its Virulence Factors InlC and ActA. Toxins 12, 411 (2020).","DOI":"10.3390\/toxins12060411"},{"key":"2026051305002175000_2026.05.10.724106v1.21","doi-asserted-by":"publisher","DOI":"10.64898\/2026.01.26.701742"},{"key":"2026051305002175000_2026.05.10.724106v1.22","first-page":"e03253","article-title":"Development and utilization of Treponema pallidum expressing green fluorescent protein to study spirochete-host interactions and antibody-mediated clearance: expanding the toolbox for syphilis research","volume":"16","year":"2024","journal-title":"mBio"},{"key":"2026051305002175000_2026.05.10.724106v1.23","doi-asserted-by":"publisher","DOI":"10.1128\/JB.186.20.7019-7022.2004"},{"key":"2026051305002175000_2026.05.10.724106v1.24","doi-asserted-by":"crossref","unstructured":"Waugh, S. , Goodyear, M. C. , Gomez, A. , Ranasinghe, A. , Lithgow, K. V. , Falsafi, R. , Hancock, R. E. W. , Lee, A. H. & Cameron, C. E . Time-course transcriptomics reveals the impact of Treponema pallidum on microvascular endothelial cell function and phenotype. Front. Microbiol. 16, (2025).","DOI":"10.3389\/fmicb.2025.1649738"},{"key":"2026051305002175000_2026.05.10.724106v1.25","doi-asserted-by":"crossref","first-page":"1051","DOI":"10.12659\/MSM.892898","article-title":"Meta-Analysis of the Association between Plasminogen Activator Inhibitor-1 4G\/5G Polymorphism and Recurrent Pregnancy Loss","volume":"21","year":"2015","journal-title":"Med Sci Monit"},{"key":"2026051305002175000_2026.05.10.724106v1.26","doi-asserted-by":"crossref","first-page":"1107","DOI":"10.1056\/NEJMoa1908753","article-title":"Causal Genetic Variants in Stillbirth","volume":"383","year":"2020","journal-title":"N Engl J Med"},{"key":"2026051305002175000_2026.05.10.724106v1.27","first-page":"4","article-title":"Brief History of Syphilis","volume":"7","year":"2014","journal-title":"J Med Life"},{"key":"2026051305002175000_2026.05.10.724106v1.28","doi-asserted-by":"crossref","first-page":"2500","DOI":"10.1021\/acsinfecdis.5c00346","article-title":"The Outer Membrane Protein Tp92 of Treponema pallidum Induces BeWo Cells Apoptosis and Oxidative Stress via the Nrf2\/keap1 Pathway","volume":"11","year":"2025","journal-title":"ACS Infect. Dis"},{"key":"2026051305002175000_2026.05.10.724106v1.29","doi-asserted-by":"crossref","unstructured":"Primus, S. , Rocha, S. C. , Giacani, L. & Parveen, N . Identification and Functional Assessment of the First Placental Adhesin of Treponema pallidum That May Play Critical Role in Congenital Syphilis. Front Microbiol 11, 621654 (2020).","DOI":"10.3389\/fmicb.2020.621654"},{"key":"2026051305002175000_2026.05.10.724106v1.30","doi-asserted-by":"publisher","DOI":"10.64898\/2026.02.04.703719"},{"key":"2026051305002175000_2026.05.10.724106v1.31","doi-asserted-by":"crossref","first-page":"e1832","DOI":"10.1371\/journal.pntd.0001832","article-title":"Whole Genome Sequence of Treponema pallidum ssp. pallidum, Strain Mexico A, Suggests Recombination between Yaws and Syphilis Strains","volume":"6","year":"2012","journal-title":"PLOS Neglected Tropical Diseases"},{"key":"2026051305002175000_2026.05.10.724106v1.32","doi-asserted-by":"publisher","DOI":"10.1016\/j.placenta.2013.12.007"},{"key":"2026051305002175000_2026.05.10.724106v1.33","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1000732"},{"key":"2026051305002175000_2026.05.10.724106v1.34","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.05899-11"},{"key":"2026051305002175000_2026.05.10.724106v1.35","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro.2016.141"},{"key":"2026051305002175000_2026.05.10.724106v1.36","doi-asserted-by":"crossref","unstructured":"Lithgow, K. V. , Tsao, E. , Schovanek, E. , Gomez, A. , Swayne, L. A. & Cameron, C. E . Treponema pallidum Disrupts VE-Cadherin Intercellular Junctions and Traverses Endothelial Barriers Using a Cholesterol-Dependent Mechanism. Front Microbiol 12, 691731 (2021).","DOI":"10.3389\/fmicb.2021.691731"},{"key":"2026051305002175000_2026.05.10.724106v1.37","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/0005-2760(71)90257-8","article-title":"Lipid metabolism in the parasitic and free-living spirochetes Treponema pallidum (Reiter) and Treponema zuelzerae","volume":"231","year":"1971","journal-title":"Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism"},{"key":"2026051305002175000_2026.05.10.724106v1.38","doi-asserted-by":"crossref","first-page":"713","DOI":"10.1128\/iai.24.3.713-719.1979","article-title":"Unique lipid composition of Treponema pallidum (Nichols virulent strain)","volume":"24","year":"1979","journal-title":"Infect Immun"},{"key":"2026051305002175000_2026.05.10.724106v1.39","doi-asserted-by":"publisher","DOI":"10.1016\/j.cell.2016.05.008"},{"key":"2026051305002175000_2026.05.10.724106v1.40","doi-asserted-by":"crossref","unstructured":"Kovarik, P. , Castiglia, V. , Ivin, M. & Ebner, F . Type I Interferons in Bacterial Infections: A Balancing Act. Front Immunol 7, 652 (2016).","DOI":"10.3389\/fimmu.2016.00652"},{"key":"2026051305002175000_2026.05.10.724106v1.41","doi-asserted-by":"crossref","unstructured":"Zhao, Y. & Liu, D . Expressions of interferon-stimulated genes in peripheral blood mononuclear cells from patients with secondary syphilis. Infection, Genetics and Evolution 96, 105137 (2021).","DOI":"10.1016\/j.meegid.2021.105137"},{"key":"2026051305002175000_2026.05.10.724106v1.42","doi-asserted-by":"crossref","unstructured":"Waugh, S. , Ranasinghe, A. , Gomez, A. , Houston, S. , Lithgow, K. V. , Eshghi, A. , Fleetwood, J. , Conway, K. M. E. , Reynolds, L. A. & Cameron, C. E . Syphilis and the host: multi-omic analysis of host cellular responses to Treponema pallidum provides novel insight into syphilis pathogenesis. Front. Microbiol. 14, (2023).","DOI":"10.3389\/fmicb.2023.1254342"},{"key":"2026051305002175000_2026.05.10.724106v1.43","doi-asserted-by":"publisher","DOI":"10.1111\/imr.13077"},{"key":"2026051305002175000_2026.05.10.724106v1.44","doi-asserted-by":"publisher","DOI":"10.1136\/sti.60.6.357"},{"key":"2026051305002175000_2026.05.10.724106v1.45","doi-asserted-by":"publisher","DOI":"10.1084\/jem.161.3.514"},{"key":"2026051305002175000_2026.05.10.724106v1.46","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.01083-10"},{"key":"2026051305002175000_2026.05.10.724106v1.47","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1913.04340020016005"},{"key":"2026051305002175000_2026.05.10.724106v1.48","doi-asserted-by":"crossref","first-page":"e44","DOI":"10.1002\/cpz1.44","article-title":"In Vitro Cultivation of the Syphilis Spirochete Treponema pallidum","volume":"1","year":"2021","journal-title":"Curr Protoc"},{"key":"2026051305002175000_2026.05.10.724106v1.49","doi-asserted-by":"crossref","unstructured":"Chen, E. Y. , Tan, C. M. , Kou, Y. , Duan, Q. , Wang, Z. , Meirelles, G. V. , Clark, N. R. & Ma\u2019ayan, A . Enrichr: interactive and collaborative HTML5 gene list enrichment analysis tool. BMC Bioinformatics 14, 128 (2013).","DOI":"10.1186\/1471-2105-14-128"},{"key":"2026051305002175000_2026.05.10.724106v1.50","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkw377"},{"key":"2026051305002175000_2026.05.10.724106v1.51","doi-asserted-by":"crossref","first-page":"e90","DOI":"10.1002\/cpz1.90","article-title":"Gene Set Knowledge Discovery with Enrichr","volume":"1","year":"2021","journal-title":"Curr Prot"}],"container-title":[],"original-title":[],"link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.64898\/2026.05.10.724106","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,13]],"date-time":"2026-05-13T12:00:44Z","timestamp":1778673644000},"score":1,"resource":{"primary":{"URL":"http:\/\/biorxiv.org\/lookup\/doi\/10.64898\/2026.05.10.724106"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,10]]},"references-count":51,"URL":"https:\/\/doi.org\/10.64898\/2026.05.10.724106","relation":{},"subject":[],"published":{"date-parts":[[2026,5,10]]},"subtype":"preprint"}}