Ivar Hordviks forskning fokuserer på komponenter i det adaptive immunsystemet hos fisk. Et langsiktig mål er å utvide spekteret av karakteriserte molekyler og utvikle verktøy som kan brukes til å studere immunresponser i eksperimenter med vaksiner og sykdomsfremkallende organismer hos fisk.

Etter at fisk dannet en egen gren på det fylogenetiske tre har det oppstått betydelige forskjeller mellom fisk og pattedyr, både med hensyn til primærsekvenser av korresponderende molekyler, og ved introduksjon av nye molekyler ved genduplikasjoner. Et eksempel på dette er evolusjonen av immunoglobulinene: Mens IgM har vært evolusjonsmessig stabil og beholdt sin opprinnelige form har IgD vært relativt labil, noe som har resultert i mange ulike IgD-strukturer i forskjellige arter. En nylig oppdaget immunoglobulintype, kalt IgT/IgZ, synes å forekomme kun hos fisk. På den andre siden finnes IgG, IgE og IgA hos pattedyr, men ikke hos fisk.

Mange oppdagelser de siste årene har vist at studier av immunsystemet hos fisk fremdeles kan by på overraskelser. Det er nærliggende å tro at økt kunnskap om immunrelaterte molekyler hos fisk vil få betydning for design av vaksineeksperimenter og tolkning av resultater. Utvikling av nye reagenser til identifisering av immunceller og måling av immunresponser er noe som etterspørres av vaksinefirmaer så vel som av mange forskere.  

Cloning and expression analysis of Atlantic halibut (Hippoglossus hippoglossus) CD3 genes
Author(s): Overgard, AC; Hordvik, I; Nerland, AH, et al.
Source: FISH & SHELLFISH IMMUNOLOGY   Volume: 27   Issue: 6   Pages: 707-713   Published: 2009

CD4 homologues in Atlantic salmon
Author(s): Moore, LJ; Dijkstra, JM; Koppang, EO, et al.
Source: FISH & SHELLFISH IMMUNOLOGY   Volume: 26   Issue: 1   Pages: 10-18   Published: 2009

Identification and characterization of a novel intraepithelial lymphoid tissue in the gills of Atlantic salmon
Author(s): Haugarvoll, E; Bjerkas, I; Nowak, BF, et al.
Source: JOURNAL OF ANATOMY   Volume: 213   Issue: 2   Pages: 202-209   Published: 2008

Characterization of the CD3 zeta, CD3 gamma delta and CD3 epsilon subunits of the T cell receptor complex in Atlantic salmon
Author(s): Liu, Y; Moore, L; Koppang, EO, et al.
Source: DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY   Volume: 32   Issue: 1   Pages: 26-35   Published: 2008

FABP3 and FABP10 in Atlantic salmon (Salmo salar L.) - General effects of dietary fatty acid composition and life cycle variations
Author(s): Jordal, AEO; Hordvik, I; Pelsers, M, et al.
Source: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY   Volume: 145   Issue: 2   Pages: 147-158   Published: OCT 2006

Myosin heavy chain mRNA expression correlates higher with muscle protein accretion than growth in Atlantic salmon, Salmo salar
Author(s): Hevroy, EM; Jordal, AEO; Hordvik, I, et al.
Source: AQUACULTURE   Volume: 252   Issue: 2-4   Pages: 453-461   Published: MAR 10 2006

Identification and characterization of a second CD4-like gene in teleost fish
Author(s): Dijkstra, JM; Somamoto, T; Moore, L, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 43   Issue: 5   Pages: 410-419   Published: FEB 2006

MHC class II+ cells in the gills of Atlantic salmon (Salmo salar L.) affected by amoebic gill disease
Author(s): Morrison, RN; Koppang, EO; Hordvik, I, et al.
Source: VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY   Volume: 109   Issue: 3-4   Pages: 297-303   Published: FEB 15 2006

Allergy to fish parvalbumins: Studies on the cross-reactivity of allergens from 9 commonly consumed fish
Author(s): Van Do, T; Elsayed, S; Florvaag, E, et al.
Source: JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY   Volume: 116   Issue: 6   Pages: 1314-1320   Published: DEC 2005

Evaluation of potential reference genes in real-time RT-PCR studies of Atlantic salmon
Author(s): Olsvik, PA; Lie, KK; Jordal, AEO, et al.
Source: BMC MOLECULAR BIOLOGY   Volume: 6   Article Number: 21   Published: NOV 17 2005

Characterisation of salmon and trout CD8 alpha and CD8 beta
Author(s): Moore, LJ; Somamoto, T; Lie, KK, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 42   Issue: 10   Pages: 1225-1234   Published: JUN 2005

Characterization of parvalbumin, the major allergen in Alaska pollack, and comparison with codfish Allergen M
Author(s): Van Do, T; Hordvik, I; Endresen, C, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 42   Issue: 3   Pages: 345-353   Published: FEB 2005

The ontogeny of MHC class I expression in rainbow trout (Oncorhynchus mykiss)
Author(s): Fischer, U; Dijkstra, JM; Kollner, B, et al.
Source: FISH & SHELLFISH IMMUNOLOGY   Volume: 18   Issue: 1   Pages: 49-60   Published: JAN 2005

Vaccine-associated granulomatous inflammation and melanin accumulation in Atlantic salmon, Salmo salar L., white muscle
Author(s): Koppang, EO; Haugarvoll, E; Hordvik, I, et al.
Source: JOURNAL OF FISH DISEASES   Volume: 28   Issue: 1   Pages: 13-22   Published: JAN 2005

Structure and organization of the T cell receptor alpha chain genes in Atlantic salmon
Author(s): Hordvik, I; Torvund, J; Moore, L, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 41   Issue: 5   Pages: 553-559   Published: JUL 2004

Granulomatous uveitis associated with vaccination in the Atlantic salmon
Author(s): Koppang, EO; Haugarvoll, E; Hordvik, I, et al.
Source: VETERINARY PATHOLOGY   Volume: 41   Issue: 2   Pages: 122-130   Published: MAR 2004

Vaccination induces major histocompatibility complex class II expression in the Atlantic salmon eye
Author(s): Koppang, EO; Bjerkas, E; Bjerkas, I, et al.
Source: SCANDINAVIAN JOURNAL OF IMMUNOLOGY   Volume: 58   Issue: 1   Pages: 9-14   Published: JUL 2003

The major allergen (parvalbumin) of codfish is encoded by at least two isotypic genes: cDNA cloning, expression and antibody binding of the recombinant allergens
Author(s): Van Do, T; Hordvik, I; Endresen, C, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 39   Issue: 10   Pages: 595-602   Published: JAN 2003

Analysis of two IgM isotypes in Atlantic salmon and brown trout
Author(s): Hordvik, I; Berven, FS; Solem, ST, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 39   Issue: 5-6   Pages: 313-321   Published: OCT 2002

Identification of a novel immunoglobulin delta transcript and comparative analysis of the genes encoding IgD in Atlantic salmon and Atlantic halibut
Author(s): Hordvik, I
Source: MOLECULAR IMMUNOLOGY   Volume: 39   Issue: 1-2   Pages: 85-91   Published: SEP 2002

Diversity of the immunoglobulin heavy chain in the Atlantic salmon (Salmo salar L.) is contributed by genes from two parallel IgH isoloci.
Author(s): Solem, ST; Hordvik, I; Killie, JEA, et al.
Source: DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY   Volume: 25   Issue: 5-6   Pages: 403-417   Published: JUN-JUL 2001

Presence of IgM in cutaneous mucus, but not in gut mucus of Atlantic salmon, Salmo salar. Serum IgM is rapidly degraded when added to gut mucus
Author(s): Hatten, F; Fredriksen, A; Hordvik, I, et al.
Source: FISH & SHELLFISH IMMUNOLOGY   Volume: 11   Issue: 3   Pages: 257-268   Published: APR 2001

Expression and analysis of recombinant salmon parvalbumin, the major allergen in atlantic salmon (Salmo salar)
Author(s): Van Do, T; Hordvik, I; Endresen, C, et al.
Source: SCANDINAVIAN JOURNAL OF IMMUNOLOGY   Volume: 50   Issue: 6   Pages: 619-625   Published: 1999

Molecular cloning and phylogenetic analysis of the Atlantic salmon immunoglobulin D gene
Author(s): Hordvik, I; Thevarajan, J; Samdal, I, et al.
Source: SCANDINAVIAN JOURNAL OF IMMUNOLOGY   Volume: 50   Issue: 2   Pages: 202-210   Published: AUG 1999

The putative polymerase sequence of infectious salmon anemia virus suggests a new genus within the Orthomyxoviridae
Author(s): Krossoy, B; Hordvik, I; Nilsen, F, et al.
Source: JOURNAL OF VIROLOGY   Volume: 73   Issue: 3   Pages: 2136-2142   Published: MAR 1999

The impact of ancestral tetraploidy on antibody heterogeneity in salmonid fishes
Author(s): Hordvik, I
Source: IMMUNOLOGICAL REVIEWS   Volume: 166   Pages: 153-157   Published: DEC 1998

Molecular phylogeny of microsporidians with particular reference to species that infect the muscles of fish
Author(s): Nilsen, F; Endresen, C; Hordvik, I
Source: JOURNAL OF EUKARYOTIC MICROBIOLOGY   Volume: 45   Issue: 5   Pages: 535-543   Published: SEP-OCT 1998

Structure and organization of the immunoglobulin M heavy chain genes in Atlantic salmon, Salmo salar
Author(s): Hordvik, I; Lindstrom, CD; Voie, AM, et al.
Source: MOLECULAR IMMUNOLOGY   Volume: 34   Issue: 8-9   Pages: 631-639   Published: JUN 1997

Cloning of T-cell antigen receptor beta chain cDNAs from Atlantic salmon (Salmo salar)
Author(s): Hordvik, I; Jacob, ALJ; Charlemagne, J, et al.
Source: IMMUNOGENETICS   Volume: 45   Issue: 1   Pages: 9-14   Published: 1996

Cloning of two distinct cDNAs encoding parvalbumin, the major allergen of Atlantic salmon (Salmo salar)
Author(s): Lindstrom, CDV; VanDo, T; Hordvik, I, et al.
Source: SCANDINAVIAN JOURNAL OF IMMUNOLOGY   Volume: 44   Issue: 4   Pages: 335-344   Published: OCT 1996

Immune genes of the Atlantic salmon, Salmo salar L.: Application of modern molecular genetic techniques to the study of antibodies and major histocompatibility complex antigens
Author(s): Hordvik, I.
Source: Aquaculture and Fisheries Management   Volume: 25   Issue: 1   Pages: 47-53   Published: 1994

Haploid gynogenesis: A powerful strategy for linkage analysis in fish
Author(s): Lie, O.; Slettan, A.; Lingaas, F., et al.
Source: Animal Biotechnology   Volume: 5   Issue: 1   Pages: 33-45   Published: 1994

MOLECULAR-CLONING OF MAJOR HISTOCOMPATIBILITY COMPLEX CLASS-I CDNAS FROM ATLANTIC SALMON (SALMO-SALAR)
Author(s): GRIMHOLT, U; HORDVIK, I; FOSSE, VM, et al.
Source: IMMUNOGENETICS   Volume: 37   Issue: 6   Pages: 469-473   Published: FEB 1993

CLONING AND SEQUENCE-ANALYSIS OF CDNAS ENCODING THE MHC CLASS-II BETA-CHAIN IN ATLANTIC SALMON (SALMO-SALAR)
Author(s): HORDVIK, I; GRIMHOLT, U; FOSSE, VM, et al.
Source: IMMUNOGENETICS   Volume: 37   Issue: 6   Pages: 437-441   Published: FEB 1993

CLONING AND SEQUENCE-ANALYSIS OF 2 ISOTYPIC IGM HEAVY-CHAIN GENES FROM ATLANTIC SALMON, SALMO-SALAR L
Author(s): HORDVIK, I; VOIE, AM; GLETTE, J, et al.
Source: EUROPEAN JOURNAL OF IMMUNOLOGY   Volume: 22   Issue: 11   Pages: 2957-2962   Published: NOV 1992