{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:39:23Z","timestamp":1785425963597,"version":"3.56.0"},"reference-count":46,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T00:00:00Z","timestamp":1782864000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Department of Biological Sciences at Seton Hall University"},{"id":[{"id":"https:\/\/ror.org\/007tn5k56","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objective: Francisella tularensis is a highly infectious intracellular pathogen that causes severe pulmonary tularemia following aerosol exposure, yet no licensed vaccine exists. Because infection initiates at the respiratory mucosa, understanding mechanisms of protective pulmonary immunity is critical for mucosal vaccine development. This study investigated the role of lung-resident \u03b3\u03b4 T cells following intranasal immunization with inactivated F. tularensis (iFt) and subsequent lethal challenge with live vaccine strain (LVS). Methods: Mice were intranasally immunized with iFt and later challenged with lethal LVS. Pulmonary immune responses were evaluated using flow cytometry and cytokine analysis. Recruitment of \u03b3\u03b4 and \u03b1\u03b2 T cells, production of IL-17 and IFN-\u03b3, neutrophil infiltration, and \u03b3\u03b4 T cell memory phenotypes were assessed in na\u00efve and immunized mice following infection. Results: Primary LVS infection induced rapid recruitment of \u03b3\u03b4 T cells to the lung beginning on Day 2 post-infection, preceding significant \u03b1\u03b2 T cell accumulation. Increased pulmonary IL-17 and IFN-\u03b3 correlated with expansion of IL-17\u2013 and IFN-\u03b3\u2013associated \u03b3\u03b4 T cell populations. Following iFt immunization, mice demonstrated enhanced survival after lethal LVS challenge, accompanied by early increases in pulmonary IL-17 and IL-17 producing \u03b3\u03b4 T cells. Immunized mice also exhibited expansion of effector memory and central memory \u03b3\u03b4 T cell populations associated with IL-17 production. Conclusions: These findings identify IL-17 producing \u03b3\u03b4 T cells as contributors to early mucosal immunity following intranasal vaccination against F. tularensis and suggest that targeting lung-resident \u03b3\u03b4 T cells may support the development of next-generation mucosal vaccines against respiratory pathogens.<\/jats:p>","DOI":"10.3390\/vaccines14070590","type":"journal-article","created":{"date-parts":[[2026,7,1]],"date-time":"2026-07-01T16:50:33Z","timestamp":1782924633000},"page":"590","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Potential Roles of Gamma-Delta T Cells in a Bacterial Immun-Ization Model"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-8918-9985","authenticated-orcid":false,"given":"Lee Anne","family":"Talbot","sequence":"first","affiliation":[{"name":"Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raffi","family":"Manjikian","sequence":"additional","affiliation":[{"name":"Instructor of Chemistry, School of STEM, Hudson County Community College, Jersey City, NJ 07306, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Constantine","family":"Bitsaktsis","sequence":"additional","affiliation":[{"name":"Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2274638","DOI":"10.1080\/21505594.2023.2274638","article-title":"Pathogenicity and virulence of Francisella tularensis","volume":"14","author":"Degabriel","year":"2023","journal-title":"Virulence"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1007\/s12223-016-0461-z","article-title":"Tularemia vaccines","volume":"61","author":"Putzova","year":"2016","journal-title":"Folia Microbiol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Babadjanova, Z., Wiedinger, K., Gosselin, E.J., and Bitsaktsis, C. 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