title: Nasal immunity is an ancient arm of the mucosal immune system of vertebrates.
abstract: The mucosal surfaces of all vertebrates have been exposed to similar evolutionary pressures for millions of years. In terrestrial vertebrates such as birds and mammals, the nasopharynx-associated lymphoid tissue (NALT) represents a first line of immune defence. Here we propose that NALT is an ancient arm of the mucosal immune system not restricted to terrestrial vertebrates. We find that NALT is present in rainbow trout and that it resembles other teleost mucosa-associated lymphoid tissues. Trout NALT consists of diffuse lymphoid cells and lacks tonsils and adenoids. The predominant B-cell subset found in trout NALT are IgT(+) B cells, similar to skin and gut. The trout olfactory organ is colonized by abundant symbiotic bacteria, which are coated by trout secretory immunoglobulin. Trout NALT is capable of mounting strong anti-viral immune responses following nasal delivery of a live attenuated viral vaccine. Our results open up a new tool for the control of aquatic infectious diseases via nasal vaccination.
authors.affiliation: Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Luca
authors.initials: L
authors.lastname: Tacchi
authors.affiliation: Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Rami
authors.initials: R
authors.lastname: Musharrafieh
authors.affiliation: Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Erin T
authors.initials: ET
authors.lastname: Larragoite
authors.affiliation: Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Crossey
authors.affiliation: Department of Mathematics and Statistics, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Erik B
authors.initials: EB
authors.lastname: Erhardt
authors.affiliation: Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland.
authors.forename: Samuel A M
authors.initials: SAM
authors.lastname: Martin
authors.affiliation: Research Division Clear Springs Foods Inc, Buhl, Idaho, USA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: LaPatra
authors.affiliation: Center for Evolutionary and Theoretical Immunology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Salinas