{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:03:30Z","timestamp":1785420210993,"version":"3.56.0"},"reference-count":45,"publisher":"American Society for Microbiology","issue":"7","license":[{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T00:00:00Z","timestamp":1784678400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["223743\/Z\/21\/Z"],"award-info":[{"award-number":["223743\/Z\/21\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Appl Environ Microbiol"],"published-print":{"date-parts":[[2026,7,22]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title\/>\n                    <jats:p>\n                      <jats:italic toggle=\"yes\">Orientia tsutsugamushi<\/jats:italic>\n                      (\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      ), the causative agent of scrub typhus, is an obligate intracellular bacterium naturally maintained in\n                      <jats:italic toggle=\"yes\">Leptotrombidium<\/jats:italic>\n                      mites, yet its interactions within arthropod hosts remain poorly understood. Here, we employed two tick cell lines,\n                      <jats:italic toggle=\"yes\">Ixodes scapularis<\/jats:italic>\n                      ISE6 and\n                      <jats:italic toggle=\"yes\">Rhipicephalus microplus<\/jats:italic>\n                      BME\/CTVM23, as arthropod models to investigate the intracellular lifecycle of\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      strains TA686 and Karp. Both strains efficiently infected tick cells and replicated within them, with ISE6 supporting more robust growth. Electron microscopy images revealed that\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      maintains its characteristic cytoplasmic, non-vacuolar location in tick cells and exits infected cells by budding off the surface in a membrane-encased structure. Time-course immunofluorescence imaging demonstrated progressive intracellular replication and dynamic expression of\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      outer membrane autotransporters ScaA and ScaC, with ScaC enriched early in infection and ScaA at later stages. A microscopy-based analysis of metabolic activity using a clickable methionine analog L-homopropargylglycine showed that high ScaA abundance correlated with reduced translational activity, suggesting a link between ScaA abundance and late-stage or extracellular-like developmental states. The subcellular location of\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      in tick cells differs from the characteristic dynein-driven perinuclear clustering observed in mammalian cells and was not sensitive to disruption of microtubules, suggesting a distinct mode of distribution. Together, these findings identify tick cell lines as tractable and biologically relevant arthropod models for studying\n                      <jats:italic toggle=\"yes\">Ot<\/jats:italic>\n                      and dissecting host-microbe interactions.\n                    <\/jats:p>\n                    <jats:sec>\n                      <jats:title>IMPORTANCE<\/jats:title>\n                      <jats:p>\n                        <jats:italic toggle=\"yes\">Orientia tsutsugamushi<\/jats:italic>\n                        , the causative agent of scrub typhus, is an obligate intracellular bacterium naturally maintained in trombiculid mites, yet its interactions with arthropod host cells remain poorly understood. This study establishes, for the first time, a tractable\n                        <jats:italic toggle=\"yes\">in vitro<\/jats:italic>\n                        arthropod model for\n                        <jats:italic toggle=\"yes\">O. tsutsugamushi<\/jats:italic>\n                        using tick cell lines from\n                        <jats:italic toggle=\"yes\">Ixodes scapularis<\/jats:italic>\n                        and\n                        <jats:italic toggle=\"yes\">Rhipicephalus microplus<\/jats:italic>\n                        . We demonstrate that both virulent and avirulent\n                        <jats:italic toggle=\"yes\">Orientia<\/jats:italic>\n                        strains efficiently infect and replicate in these cells while maintaining their characteristic cytoplasmic location and budding mode of exit. Distinct temporal expression of the bacterial autotransporters ScaA and ScaC and their relationship to metabolic activity reveal stage-specific adaptations during infection. These findings provide essential mechanistic insight into how\n                        <jats:italic toggle=\"yes\">O. tsutsugamushi<\/jats:italic>\n                        persists and develops within arthropod hosts. The tick cell model enables comparative studies of host-pathogen interactions across vector species and offers a powerful tool to investigate transmission biology and potential targets for intervention.\n                      <\/jats:p>\n                    <\/jats:sec>\n                  <\/jats:sec>","DOI":"10.1128\/aem.02540-25","type":"journal-article","created":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T13:00:49Z","timestamp":1781269249000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["Tick cells as a tractable arthropod model for studying\n                    <i>Orientia tsutsugamushi<\/i>"],"prefix":"10.1128","volume":"92","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5910-4101","authenticated-orcid":false,"given":"Magda A.","family":"Rogowska-van der Molen","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/013meh722","id-type":"ROR","asserted-by":"publisher"}],"name":"Cambridge Institute for Medical Research, University of Cambridge","place":["Cambridge, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Filomena","family":"Gallo","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/013meh722","id-type":"ROR","asserted-by":"publisher"}],"name":"Microscopy Bioscience Platform, School of Biological Sciences, University of Cambridge","place":["Cambridge, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lesley","family":"Bell-Sakyi","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04xs57h96","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool","place":["Liverpool, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5802-4580","authenticated-orcid":true,"given":"Jeanne","family":"Salje","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/013meh722","id-type":"ROR","asserted-by":"publisher"}],"name":"Cambridge Institute for Medical Research, University of Cambridge","place":["Cambridge, United Kingdom"]},{"id":[{"id":"https:\/\/ror.org\/013meh722","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Biochemistry, University of Cambridge","place":["Cambridge, United Kingdom"]},{"id":[{"id":"https:\/\/ror.org\/013meh722","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathology, University of Cambridge","place":["Cambridge, United Kingdom"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.3390\/tropicalmed3010008"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.7759\/cureus.47290"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0006062"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0005838"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijid.2024.107151"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.01526-10"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa1603657"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.3201\/eid2609.200918"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41579-020-00507-2"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-022-31176-9"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.micpath.2013.06.002"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.tim.2020.02.014"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.01620-05"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/msphere.00268-23"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.00284-24"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-025-61105-5"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.30.1.231-243.1980"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.micinf.2011.03.003"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1099\/ijs.0.011049-0"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.pt.2007.07.009"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcpa.2003.12.002"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1012833"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.1006\/jipa.1996.0050"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ttbdis.2012.10.020"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.37.8.2518-2524.1999"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.2307\/3282757"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0004009"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.xpro.2022.101588"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","unstructured":"Salje J. 2025. Quantifying Orientia tsutsugamushi and other Rickettsiales bacteria by real time qPCR v1. Protocols.io. doi:10.17504\/protocols.io.8epv5nz4jv1b\/v1","DOI":"10.17504\/protocols.io.8epv5nz4jv1b\/v1"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.mimet.2019.105812"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ttbdis.2016.01.013"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.01342-21"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1348-0421.2003.tb03442.x"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pntd.0001466"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.69.1.494-500.2001"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1155\/2008\/623145"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1079\/AHRR200241"},{"key":"e_1_3_3_39_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ttbdis.2015.07.001"},{"key":"e_1_3_3_40_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.nmni.2018.02.012"},{"key":"e_1_3_3_41_2","doi-asserted-by":"publisher","DOI":"10.1186\/1944-3277-9-9"},{"key":"e_1_3_3_42_2","doi-asserted-by":"publisher","DOI":"10.3389\/fcimb.2023.1175688"},{"key":"e_1_3_3_43_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41564-022-01169-x"},{"key":"e_1_3_3_44_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1348-0421.1999.tb03359.x"},{"key":"e_1_3_3_45_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-018-35775-9"},{"key":"e_1_3_3_46_2","doi-asserted-by":"publisher","DOI":"10.3346\/jkms.2015.30.7.866"}],"container-title":["Applied and Environmental Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/aem.02540-25","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/aem.02540-25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T13:04:08Z","timestamp":1784725448000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/aem.02540-25"}},"subtitle":[],"editor":[{"given":"Pablo","family":"Tortosa","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,7,22]]},"references-count":45,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2026,7,22]]}},"alternative-id":["10.1128\/aem.02540-25"],"URL":"https:\/\/doi.org\/10.1128\/aem.02540-25","relation":{},"ISSN":["0099-2240","1098-5336"],"issn-type":[{"value":"0099-2240","type":"print"},{"value":"1098-5336","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,22]]},"assertion":[{"value":"2025-12-27","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-05-20","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-06-12","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e02540-25"}}