John Hansen

John Hansen

Research Microbiologist

Western Fisheries Research Center

Phone: 206-526-6588
Fax: 206-526-6654

6505 NE 65Th Street
Seattle, WA 98115




1995-2001: Postdoc, Basel Institute for Immunology, Basel, Switzerland.

1991-1995: Ph.D.  Genetics/Immunology, Dept. of Microbiology, Oregon State University.

1984-1988: B.S. in  Zoology & Chemistry, University of Wisconsin at Eau Claire.

Dr. Hansen is a Research Immunologist at the Western Fisheries Research Center. His laboratory utilizes a basic research, comparative approach to understand host-pathogen interactions in fish and the impact of environmental chemicals on immunity.


Professional Experience:

Research Immunologist/Project Leader: USGS Western Fisheries Research Center, Aug. 2004-present.

Current projects:

1.  Zebrafish as an alternative model for assessing the impact of environmental chemicals on vertebrate health.

2.  Inflammatory processes during disease and stress

3.  US Veterinary Immune Reagent Network (

4.  Zebrafish and trout as models for understanding host-pathogen interactions in fish.

Affiliate Associate Professor: Global Health and Pathobiology, University of Washington, 2004-present.

Current laboratory members: 

James C. Woodson, Sr Biological Research Technician

Emma Deas, Undergraduate Researcher UW

Victoria McPherson, Undergraduate Researcher UW


Former scholars (Current position): 

Postdoctoral Fellows:

Siba Das, Regulation of mRNA/miRNAs during EDC exposure (Pacific NW Diabetes Res Institute)

Kerry Laing, T-cell co-receptors in teleost fish (UW Department of Medicine)

Damian Kraus, Immune response to VHSV in herring ( )

Ph.D. Students

Lucia Vojtech, Thesis "Evolutionary conservation  of the Innate Immune Responses to Francisella Infection in the Zebrafish" 

(Acting Assistant Professor, UW Department of Obstetrics and Gynecology)

Eric Landis, Thesis "Characterization and transcriptional analysis of rainbow trout MHC class 1 pathway genes in response to viral infection"

(Biologist, FDA)

UW Undergraduate Reseachers

Rachel Bessire, "Induction of proinflammatory genes during acute infection with wild type and pdpA knockouts of Francisella noatunensis" (Unv. of MI graduate School of Public Health)

Patrick Chen, "Induction of proinflammatory genes during acute infection with wild type and pdpA knockouts of Francisella noatunensis" (Balor School of Medicine, graduate school of Molecular Microbiology)

Julia Lister, "Impact of flame retardants and estradiol on the immune system of developing embryos" (Washington State University, Veterinary School)

Karina Ray, Attenuation of the fish pathogen Francisella noatunensis by mutation of the pathogenicity island gene pdpA (NYU Langone Medical Center, Genome Technology Center)

Lauren Summers, Impact of cadmium on the respiratory burst zebrafish ( Swedish Cancer Institue, Seattle-Research Coordinator)

Nicole Sharping, Functional analysis of the zebrafish inflammasome ( University of Pittsburgh, Graduate Student--School of Medicine, Biomed program)

Hoshi Suigera, Type 1 interferon responses in trout during viral infection (Veterinary research)

Samantha Badil, Role of RAG2 knockouts during Francisella infection in zebrafish (UW Department of Immunology, Research Scientist)

Annalee Herrera, Development of monoclonal antibodies for trout leukocytes (Ada Developers Academy, Software Development)

Aaron Black, Regulation of an immunoproteasome gene in herring during acute VHS infection (UPENN, Graduate student Perelman School of Medicine)








Our group at the WFRC focuses on mediators of inflammation in fish, the development of immune-related tools (mAbs)  for salmonids and the impact of endocrine disrupting compounds (e.g. estrogenic compounds) on immune response potential. We are particularly interested how early life exposures to EDC disrupt disease susceptibility. To better appreciate these interactions, we have developed specific research projects that utilize zebrafish. Zebrafish present an attractive model for studies involving fish and vertebrate health owing to the availability of genomic and genetic resourses for this model organism. Current zebrafish-related projects include assessing virulence factors of Francisella noatunensis (fish specific pathogen) and the impact of endocrine disruptors on fish health. These research efforts have translational value for both human and fish health. Ultimately, our goal is to better understand how pathogens and host immune responses contribute to pathogenesis &/or immunity and how this information can be applied to vertebrate health.

Professional Experience:

Research Immunologist/Project Leader: USGS Western Fisheries Research Center, Aug. 2004-present.

Current projects:

1.              Zebrafish as a model for understanding host-pathogen interactions in fish: use of functional genomics

2.              Pro-inflammatory responses to come

3.              US Veterinary Immune Reagent Network (

4.              Development of zebrafish as an alternative model for assessing the impact of environmental chemicals on vertebrate health.

Affiliate Associate Professor: Global Health and Pathobiology, University of Washington, 2004-present.

Assistant Professor: Center of Marine Biotechnology, University of Maryland, 2001-2004. Directed research projects looking at the functional genomics of antigen presentation, evolution the immune system and development of cellular immunity in teleosts.

Adjunct Assistant Professor: Molecular Medicine, University of Maryland Baltimore (2002-2006).

Member: Basel Institute for Immunology (with Dr. Louis Du Pasquier. Examined the organization, expression and functionality of the major histocompatibility locus (MHC) in teleosts and the generation of molecular and cellular reagents for examining the development and function of trout leukocytes. (1995-2001).

Graduate Research Assistant, Dept. of Microbiology (with Dr. Steve Kaattari), Oregon State University, 1991-1995. Ph.D. thesis research: Characterization of B-cell lymphopoiesis in rainbow trout.

Senior Laboratory Technician, Immunobiology Section-VA Hospital, Minneapolis, MN, 1988-1991. Investigating the role(s) that pro-inflammatory cytokines play in the pathogenesis of alcoholic liver disease.







Ray, K., Culcutt, M., Woodson, JC., and Hansen, J.D. Virulence factors encoded by the Francisella tularensis pathogenicity island are functionally conserved in the fish pathogen Francisella noatunensisIn preparation.

Hansen, J.D., Das S.D., Woodson, J.C, Bammler, T, Bayer, D., Nicks, D.,  Gallagher, E., Winton, J., and D.E. Tillitt. EE2 impacts genes and pathways for innate immunity in zebrafish. In preparation.

Soto, E., Halliday-Simmonds, I., Francis, S., Kearney, MT., and J.D. Hansen. Biofilm formation of Francisella noatunensis subsp. orientalis. (2015) Vet Microbiology 181, 313-317. 


Saha NR, Ota T, Litman GW, Hansen, J, Parra Z, Hsu E, Buonocore F, Canapa A, Cheng JF, Amemiya CT. Genome complexity in coelacanth is reflected in its adaptive immune system. Journal of Experimental Zoology-Molecular and Developmental Evolution: (2014) Sep;322(6):438-63.

Boudinot, P., Zou, J., Ota, T., Buonocore, F., Scapigliati, G., Canapa, A., Cannon, J., Litman, G., and J.D. Hansen. A tetrapod-like repertoire of innate immune receptors and effectos for Latimeria: an emphasis on antiviral immunity. Journal of Experimental Zoology-Molecular and Developmental Evolution: (2014) Sep;322(6):415-37


Phillips RB, Dekoning JJ, Brunelli JP, Faber-Hammond JJ, Hansen JD, Christensen KA, Renn SC, Thorgaard GH. Characterization of the Omy1 region on the trout Y chromosome. (2012). International J Genomics. ID 261730


Vojtech, L.V., Scharping, N., Woodson, J.D. and J.D. Hansen. Roles of inflammatory caspases during processing of  zebrafish interleukin-1b in Francisella noatunensis infection. 2012 Infection and Immunity 80:2878-85. 

Lefebvre, K.A., Frame, E.R., Gulland, F., Hansen, J.D., Kendrick, P.S., Beyer, R.P., Bammler, T.K., Farin, F.M., Hiolski, E.M., Smith, D.R., and D.J. Marcinek. (2012) A novel antibody-based biomarker for chronic algal toxin expsoure and sub-acute neurotoxicity. Plos One 7:e36213

Hansen, J.D., Woodson, J.D., Hershberger, P.K., Grady, C., Gregg, J.L. and M.K. Purcell. (2012) Induction of anti-viral genes during acute infection with Viral hemorrhagic septicemia virus (VHSV) genogroup IVa in Pacific herring (Clupea pallasii). Fish and Shellfish Immunology 32: 259-267.

Gomez-Ramirez, F., Green, W., Rego, K., Hansen, J.D., Costa, G., Kataria, P and E.S. Bromage. (2012) Discovery and characterization of secretory IgD in rainbow trout: sIgD is produced through a novel splicing mechanism.  Journal of Immunology 188: 1341-1349.


Laing, K.J., and Hansen, J.D. Fish T cells: recent advances through genomics. Developmental and Comparative Immunology. 35: 1282-95.

Hansen, J.D., Vojtech, L., and Laing, K.J. Sensing disease and danger: a survey of vertebrate PRRs and their origins. Developmental and Comparative Immunology 35 (9): 886-897.

Hansen, J.D., Farrugia, T.J., Woodson, J.C., and Laing, K.J. Description of an elasmobranch TCR coreceptor: CD8a from Rhinobatos productusDevelopmental and Comparative Immunology 35: 452-460.

Purcell, M.K., Mercy, I.S., Kurath, G., and Hansen, J.D. Microarray analysis of rainbow trout infected with two strains of Infectious hematopoietic necrosis virus that differ in virulence. Fish and Shellfish Immunology: 30: 84-93.


Vojtech, L.N., Sanders, G.E., Conway, C., Ostland, V. and Hansen, J.D. Host immune response and acute disease in a zebrafish model of Francisella pathogenesis. Infection & Immunity 77:914-25.

Purcell, M.K., Laing, K.J., Woodson, J.C, Thorgaard, G.H. and Hansen, J.D. Characterization of the interferon genes in homozygous rainbow trout reveals two novel genes, alternate splicing and differential regulation of duplicated genes.  Fish Shellfish Immunology 26:293-30.

Hansen, J.D., Du Pasquier, L., Lefranc, MP., Lopez, V., Benmansour, A and  Boudinot, P. The B7 family of immunoregulatory receptors: a comparative and evolutionary perspective. Molecular Immunology 46:457-72.


Landis, E. L. Purcell, M., Thorgaard, G. and Hansen, J.D. Transcriptional profiling of MHC class I genes in rainbow trout infected with IHNV. Molecular Immunology 45: 1646-1657.

Laing, K., Purcell, M., Winton, J. and Hansen, J.D. A genomic view of the NOD like receptor family in teleost fish: identification of a novel subfamily in zebrafish. BMC Evolutionary Biology 8:42-57.


Laing, K., Dutton, S., and Hansen, J.D. Molecular and biochemical analysis of rainbow trout LCK suggests a conserved mechanism for T-cell signaling in gnathostomes. Molecular Immunology 44:2737-48. 

Palti, Y., Rodriquez, M.F., Gahr, S.A. and Hansen, J.D. Evolutionary history of the ABCB2 genomic region in teleosts. Developmental and Comparative Immunology 31:483-98.

Bernard, D., Hansen, J.D., Du Pasquier, L., LeFranc, ML., Benmansour, A., and Boudinot, P. Costimulatory receptors in jawed vertebrates: conserverd CD28, odd CTLA4 and multiple BTLAs. Developmental and Comparative Immunology31:255-71.


Laing, K., Zhou, J., Purcell, M.K., Phillips, R., Secombes., C.J. and Hansen, J.D. Evolution of the CD4 family: teleost fish possess two divergent forms of CD4 in addition to LAG-3. Journal of Immunology 177: 3939-3951.

Purcell, M.K., K.M. Nichols, J.R. Winton, G.K. Kurath, G.H. Thorgaard, P. Wheeler, J.D. Hansen, R.P. Herwig and L.K. Park. Comprehensive gene expression profiling following DNA vaccination against infectious hematopoietic necrosis virus. Molecular Immunology: 43:2089-2106.

Landis, E.L., Palti, Y., DeKoning, J., Drew, R, Phillips, R. and Hansen, J.D. Identification and regulatory analysis of rainbow trout tapasin and tapasin-related  genes. Immunogenetics 58: 56-69.

Bernard, D., Riteau, B., Hansen, J.D., Phillips, R., Boudinot, P., and Benmansour, A. Costimulatory receptors in a teleost fish: typical CD28, elusive CTLA4. Journal of Immunology 176: 4191-2000.


Hansen JD, Landis ED, Phillips RB. Discovery of a unique Ig heavy-chain isotype (IgT) in rainbow trout: Implications for a distinctive B cell developmental pathway in teleost fish. Proc. Natl. Acad. Sci. (PNAS) U S A. 102:6919-24.

H. Boshra.,Wang, T., Hove-Madsen, L., Hansen, J.D., Li, J., Matlapudi, A., Secombes, C., Tort, L., and Sunyer, J.O. Characterization of a C3a receptor in rainbow trout and Xenopus: The first identification of a C3a receptor in a non-mammalian species. Journal of Immunology 175:2427-37.