{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T18:13:43Z","timestamp":1762452823215,"version":"build-2065373602"},"reference-count":54,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T00:00:00Z","timestamp":1762387200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"McNeese State University College of Science McElven Endowed Professorship"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Despite their ecological importance and unique evolutionary history, reptiles remain underrepresented in immunological research. The innate immunity of the cottonmouth (Agkistrodon piscivorus), a semi-aquatic pit viper native to the southeastern United States, was characterized to provide insight into the molecular and cellular mechanisms underlying its first line of defense against pathogens. Plasma collected from wild A. piscivorus exhibited strong antibacterial activities against both Gram-negative and Gram-positive bacteria. In addition, plasma from A. piscivorus showed potent hemolytic activities in unsensitized sheep red blood cell (SRBC) hemolysis assays. This activity was concentration-, time-, and temperature-dependent. In addition, the hemolytic activity was inhibited by mild heat treatment (56 \u00b0C, 30 min) of plasma and proteases and also by EDTA, suggesting that the hemolytic activity was due to the presence of serum complement proteins. SDS-PAGE analysis of plasma proteins isolated from a mannan-agarose affinity column revealed the presence of a protein with a mass of 36 kDa, raising the strong possibility that the lectin pathway of complement activation is active. The EC50 for hemolysis of SRBCs by plasma from A. piscivorus was approximately 10\u2013100\u00d7 lower than that of any other reptilian species described. This is the first study to characterize innate immunity in A. piscivorus.<\/jats:p>","DOI":"10.3390\/ani15213223","type":"journal-article","created":{"date-parts":[[2025,11,6]],"date-time":"2025-11-06T17:51:43Z","timestamp":1762451503000},"page":"3223","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Innate Immunity in the Cottonmouth Watersnake (Agkistrodon piscivorus)"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6444-4012","authenticated-orcid":false,"given":"Mark","family":"Merchant","sequence":"first","affiliation":[{"name":"Department of Chemistry and Physics, McNeese State University, Lake Charles, LA 70609, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Justin","family":"Epperson","sequence":"additional","affiliation":[{"name":"Department of Chemistry, McNeese State University, Lake Charles, LA 70609, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sarah","family":"Baker","sequence":"additional","affiliation":[{"name":"Department of Biology, McNeese State University, Lake Charles, LA 70605, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,6]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1167","DOI":"10.1016\/S1286-4579(01)01477-0","article-title":"How the immune system protects the host from infection","volume":"13","author":"Janeway","year":"2001","journal-title":"Microbes Infect."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e714","DOI":"10.1002\/mco2.714","article-title":"The interaction of innate immune and adaptive immune system","volume":"5","author":"Wang","year":"2024","journal-title":"MedComm"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1038\/nrg2703","article-title":"Origin and evolution of the adaptive immune system: Genetic events and selective pressures","volume":"11","author":"Flajnik","year":"2020","journal-title":"Nat. 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