Periodontitis Primes the Oral Microenvironment for PS-Dependent Non-Canonical Entry Pathways Linked to SARS-CoV-2 Susceptibility

Periodontitis Primes the Oral Microenvironment for PS-Dependent Non-Canonical Entry Pathways Linked to SARS-CoV-2 Susceptibility | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Periodontitis Primes the Oral Microenvironment for PS-Dependent Non-Canonical Entry Pathways Linked to SARS-CoV-2 Susceptibility Araceli Valverde, Kristelle Capistrano, Raza Ali Naqvi, Sarah Elshourbagy, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9163482/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract SARS-CoV-2 infection extends beyond the respiratory tract, with the oral cavity emerging as a critical site of viral activity shaped by epithelial receptor expression, microbial interactions, and inflammatory status. Periodontal disease (PD), a chronic dysbiotic condition, may heighten susceptibility to SARS-CoV-2 through inflammation-driven upregulation of non-canonical viral entry pathways. In this study, we investigated genes in the phosphatidylserine (PS)–dependent pathway, including ADAM17, ATP11c, TIM1, TIM3, and TIM4, in gingival tissue, saliva, and oral keratinocytes to define how PD and SARS-CoV-2 coordinately modulate oral viral entry mechanisms. Prepandemic gingival biopsies revealed significant upregulation of all non-canonical receptors in inflamed tissue, indicating that PD alone establishes a permissive molecular environment for PS-mediated microbial entry. In a post-vaccination cohort, salivary expression of these receptors was markedly elevated in COVID-19–positive individuals with PD, accompanied by significantly increased salivary PS levels, suggesting synergistic effects of viral exposure and periodontal inflammation. In vitro co-infection of primary human oral keratinocytes with SARS-CoV-2 and periodontal pathogens ( P. gingivalis , A. actinomycetemcomitans ) induced robust, synergistic activation of PS-dependent entry genes, particularly TIM family receptors. Together, these findings identify PS and its associated receptors as inflammation-responsive mediators that expand SARS-CoV-2 entry routes in the oral mucosa. This work highlights a mechanistic intersection between COVID-19 and periodontal disease, with implications for viral persistence, immune dysregulation, and long-term oral health outcomes. SARS-CoV-2 Oral Mucosal Immunity Oral Biology Long Covid Phospholipids phosphatidylserine (PS) Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 10 May, 2026 Reviews received at journal 21 Apr, 2026 Reviewers agreed at journal 13 Apr, 2026 Reviewers invited by journal 07 Apr, 2026 Editor invited by journal 31 Mar, 2026 Editor assigned by journal 30 Mar, 2026 Submission checks completed at journal 30 Mar, 2026 First submitted to journal 18 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9163482","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":621181649,"identity":"6e2bf929-06ae-4461-9be6-6730cecbfb73","order_by":0,"name":"Araceli Valverde","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Araceli","middleName":"","lastName":"Valverde","suffix":""},{"id":621181653,"identity":"38699a61-ff34-4cfa-9a43-86c013d612e2","order_by":1,"name":"Kristelle Capistrano","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Kristelle","middleName":"","lastName":"Capistrano","suffix":""},{"id":621181656,"identity":"70a98ca8-c24f-49e9-a275-62002d8ada83","order_by":2,"name":"Raza Ali Naqvi","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Raza","middleName":"Ali","lastName":"Naqvi","suffix":""},{"id":621181658,"identity":"7139129f-0873-421f-8368-e577ecd725ef","order_by":3,"name":"Sarah Elshourbagy","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Sarah","middleName":"","lastName":"Elshourbagy","suffix":""},{"id":621181660,"identity":"62120064-565b-4841-b7a2-407ad22944d0","order_by":4,"name":"Sodabeh Etminan","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Sodabeh","middleName":"","lastName":"Etminan","suffix":""},{"id":621181662,"identity":"bab19180-0eb7-4f9d-be67-93c9fd49c8b6","order_by":5,"name":"Gloria Sandoval","email":"","orcid":"","institution":"Universidad Autónoma de Nuevo León","correspondingAuthor":false,"prefix":"","firstName":"Gloria","middleName":"","lastName":"Sandoval","suffix":""},{"id":621181664,"identity":"f7b96c3f-ec7e-4757-8c9b-5b53c4b7ea9f","order_by":6,"name":"Maria Bambrilla","email":"","orcid":"","institution":"Universidad Autónoma de Nuevo León","correspondingAuthor":false,"prefix":"","firstName":"Maria","middleName":"","lastName":"Bambrilla","suffix":""},{"id":621181668,"identity":"07e553ab-d5e5-4c73-9fca-64c4900a0009","order_by":7,"name":"Salvador Nares","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Salvador","middleName":"","lastName":"Nares","suffix":""},{"id":621181670,"identity":"f1f6c955-cafb-4891-bcc7-87742b09daa8","order_by":8,"name":"Deepak Shukla","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Deepak","middleName":"","lastName":"Shukla","suffix":""},{"id":621181674,"identity":"c225d35c-1044-441a-971a-de87fe661480","order_by":9,"name":"Joel Schwartz","email":"","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":false,"prefix":"","firstName":"Joel","middleName":"","lastName":"Schwartz","suffix":""},{"id":621181676,"identity":"ca79aa88-3d8e-4850-9fab-97d2e0a88917","order_by":10,"name":"Afsar Naqvi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAvUlEQVRIiWNgGAWjYDAC5gMQmp+BsQHEJUILWwKElmwgWYsBxDYitPC3sT/8XLnHzt74RnLjB4YK68QGQlokjvEYS555lsxsdiOxWYLhTDphLQz3e4DeOMDMBtTSxsDYdpiwFvlj7I9/Nhyo5zGeAdLyjwgtBscYzIC2HJYwkABpaSBCi+ExHjPLhgPHDSTOPGyWSDiWbkxQixzQYTcbDlTb87enP/zwocZalqAWVJBAmvJRMApGwSgYBbgAALB7PRmVik+0AAAAAElFTkSuQmCC","orcid":"","institution":"University of Illinois at Chicago","correspondingAuthor":true,"prefix":"","firstName":"Afsar","middleName":"","lastName":"Naqvi","suffix":""}],"badges":[],"createdAt":"2026-03-18 23:38:30","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9163482/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9163482/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107480074,"identity":"d7e66ac7-8af0-4849-adae-c5675296f11e","added_by":"auto","created_at":"2026-04-22 02:04:28","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":513739,"visible":true,"origin":"","legend":"","description":"","filename":"MainText03292026.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9163482/v1_covered_6b8b8636-9bc8-4ca9-bf0e-aadafd62608a.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Periodontitis Primes the Oral Microenvironment for PS-Dependent Non-Canonical Entry Pathways Linked to SARS-CoV-2 Susceptibility","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"SARS-CoV-2, Oral Mucosal Immunity, Oral Biology, Long Covid, Phospholipids phosphatidylserine (PS)","lastPublishedDoi":"10.21203/rs.3.rs-9163482/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9163482/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSARS-CoV-2 infection extends beyond the respiratory tract, with the oral cavity emerging as a critical site of viral activity shaped by epithelial receptor expression, microbial interactions, and inflammatory status. Periodontal disease (PD), a chronic dysbiotic condition, may heighten susceptibility to SARS-CoV-2 through inflammation-driven upregulation of non-canonical viral entry pathways. In this study, we investigated genes in the phosphatidylserine (PS)\u0026ndash;dependent pathway, including ADAM17, ATP11c, TIM1, TIM3, and TIM4, in gingival tissue, saliva, and oral keratinocytes to define how PD and SARS-CoV-2 coordinately modulate oral viral entry mechanisms. Prepandemic gingival biopsies revealed significant upregulation of all non-canonical receptors in inflamed tissue, indicating that PD alone establishes a permissive molecular environment for PS-mediated microbial entry. In a post-vaccination cohort, salivary expression of these receptors was markedly elevated in COVID-19\u0026ndash;positive individuals with PD, accompanied by significantly increased salivary PS levels, suggesting synergistic effects of viral exposure and periodontal inflammation. \u003cem\u003eIn vitro\u003c/em\u003e co-infection of primary human oral keratinocytes with SARS-CoV-2 and periodontal pathogens (\u003cem\u003eP. gingivalis\u003c/em\u003e, \u003cem\u003eA. actinomycetemcomitans\u003c/em\u003e) induced robust, synergistic activation of PS-dependent entry genes, particularly TIM family receptors. Together, these findings identify PS and its associated receptors as inflammation-responsive mediators that expand SARS-CoV-2 entry routes in the oral mucosa. This work highlights a mechanistic intersection between COVID-19 and periodontal disease, with implications for viral persistence, immune dysregulation, and long-term oral health outcomes.\u003c/p\u003e","manuscriptTitle":"Periodontitis Primes the Oral Microenvironment for PS-Dependent Non-Canonical Entry Pathways Linked to SARS-CoV-2 Susceptibility","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-13 18:31:36","doi":"10.21203/rs.3.rs-9163482/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"112957598363495811370278648552592470137","date":"2026-05-10T15:39:17+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-21T20:47:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"157328012424231389874119829799893781527","date":"2026-04-13T14:42:33+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-07T10:13:58+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-03-31T15:47:20+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-30T08:08:49+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-30T08:08:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2026-03-18T23:22:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d78a629e-4a06-4fe6-9023-8262c0f3100f","owner":[],"postedDate":"April 13th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"112957598363495811370278648552592470137","date":"2026-05-10T15:39:17+00:00","index":48,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-13T18:31:37+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-13 18:31:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9163482","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9163482","identity":"rs-9163482","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}