{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T23:41:10Z","timestamp":1791848470573,"version":"4.3.4"},"reference-count":36,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2024,9,29]],"date-time":"2024-09-29T00:00:00Z","timestamp":1727568000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"North Atlantic Treaty Organization (NATO)","award":["G5486"],"award-info":[{"award-number":["G5486"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>The use of Vaccinia virus (VACV) as a preventive vaccine against variola, the etiological agent of smallpox, led to the eradication of smallpox as a human disease. The L1 protein, a myristylated transmembrane protein present on the surface of mature virions, plays a significant role in infection and morphogenesis, is well-conserved in all orthopoxviruses, and is the target of neutralizing antibodies. DNA recombinant vaccines expressing this protein were successfully used, but they showed lower efficacy in non-human and human primates when used alone, and viral-vectored fowlpox vaccines were already proved to increase immunogenicity when used as a boost. Here, we constructed a novel fowlpox-based recombinant (FPtPA-L1R), in which the tissue plasminogen activator signal sequence was linked to the 5\u2032 end of the L1R gene to drive the L1 protein into the cellular secretion pathway. FPtPA-L1R expresses a functional heterologous protein that can be immunoprecipitated by hyperimmune rabbit serum. The protein shows cytoplasmic and membrane subcellular localizations and long-lasting expression in CEF, non-human primate Vero and human MRC-5 cells. The tissue plasminogen activator signal sequence can thus contribute significantly to the expression of the L1 protein and may enhance the immunogenicity of a putative DNA\/FP prime\u2013boost vaccine.<\/jats:p>","DOI":"10.3390\/vaccines12101115","type":"journal-article","created":{"date-parts":[[2024,9,30]],"date-time":"2024-09-30T03:12:28Z","timestamp":1727665948000},"page":"1115","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Enhanced Expression of the L1R Gene of Vaccinia Virus by the tPA Signal Sequence Inserted in a Fowlpox-Based Recombinant Vaccine"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5683-6216","authenticated-orcid":false,"given":"Antonia","family":"Radaelli","sequence":"first","affiliation":[{"name":"Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy"},{"name":"Department of Pharmacy, Faculty of Pharmacy, Catholic University \u201cOur Lady of Good Counsel\u201d, Rr. Dritan Hoxha, 123, 1001 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0222-6102","authenticated-orcid":false,"given":"Carlo","family":"Zanotto","sequence":"additional","affiliation":[{"name":"Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-6685-5767","authenticated-orcid":false,"given":"Chiara","family":"Brambilla","sequence":"additional","affiliation":[{"name":"Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-5423-0751","authenticated-orcid":false,"given":"Tommaso","family":"Adami","sequence":"additional","affiliation":[{"name":"Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129 Milan, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carlo","family":"De Giuli Morghen","sequence":"additional","affiliation":[{"name":"Department of Pharmacy, Faculty of Pharmacy, Catholic University \u201cOur Lady of Good Counsel\u201d, Rr. Dritan Hoxha, 123, 1001 Tirana, Albania"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,9,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1794","DOI":"10.1016\/j.vaccine.2007.12.059","article-title":"Short-and long-term immunogenicity and protection induced by non-replicating smallpox vaccine candidates in mice and comparison with the traditional 1st generation vaccine","volume":"26","author":"Drillien","year":"2008","journal-title":"Vaccine"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1016\/0264-410X(92)90411-C","article-title":"Potential use of nonreplicating vectors as recombinant vaccines","volume":"10","author":"Baxby","year":"1992","journal-title":"Vaccine"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1006\/viro.1993.1608","article-title":"Fowlpox Virus Host Range Restriction: Gene Expression, DNA Replication, and Morphogenesis in Nonpermissive Mammalian Cells","volume":"197","author":"Somogyi","year":"1993","journal-title":"Virology"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1586\/14760584.4.1.63","article-title":"Fowlpox virus as a recombinant vaccine vector for use in mammals and poultry","volume":"4","author":"Skinner","year":"2005","journal-title":"Expert Rev. 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