The axillary lymphoid organ is an external, experimentally accessible immune organ in the zebrafish
Lymph nodes and other secondary lymphoid organs play critical roles in immune surveillance and immune activation in mammals, but the deep internal locations of these organs make it challenging to image and study them in living animals. Here, we describe a previously uncharacterized external immune organ in the zebrafish ideally suited for studying immune cell dynamics in vivo, the axillary lymphoid organ (ALO). This small, translucent organ has an outer cortex teeming with immune cells, an inner medulla with a mesh-like network of fibroblastic reticular cells along which immune cells migrate, and a network of lymphatic vessels draining to a large adjacent lymph sac. Noninvasive high-resolution imaging of transgenically marked immune cells can be carried out in ALOs of living animals, which are readily accessible to external treatment. This newly discovered tissue provides a superb model for dynamic live imaging of immune cells and their interaction with pathogens and surrounding tissues, including blood and lymphatic vessels.
Authors
- James Iben (ORCID: https://orcid.org/0000-0002-1130-7660)
- Tanner Ford Robertson (ORCID: https://orcid.org/0000-0003-4336-3760)
- Daniel N. Lumbantobing (ORCID: https://orcid.org/0000-0002-1458-1470)
- Louis Dye (ORCID: https://orcid.org/0009-0003-6957-0095)
- Kedar Narayan (ORCID: https://orcid.org/0000-0001-7982-6494)
- Daniel Castranova (ORCID: https://orcid.org/0000-0002-2845-9708)
- Gilseung Park (ORCID: https://orcid.org/0000-0003-3605-8928)
- Anna Huttenlocher A (ORCID: https://orcid.org/0000-0001-7940-6254)
- Brant M. Weinstein (ORCID: https://orcid.org/0000-0003-4136-4962)
- Kiyohito Taimatsu
- Lynne R. Parenti (ORCID: https://orcid.org/0000-0002-3279-7689)
- J. Kimble Frazer (ORCID: https://orcid.org/0000-0003-2936-2817)
- Yiran Hou (ORCID: https://orcid.org/0000-0002-6086-6434)
- Jong S. Park (ORCID: https://orcid.org/0000-0001-7989-4630)
- Reegan J. Willms
- Miranda Marvel (ORCID: https://orcid.org/0000-0003-4043-1887)
- Marina Venero Galanternik (ORCID: https://orcid.org/0000-0002-0262-1754)
- Edan Foley (ORCID: https://orcid.org/0000-0001-8666-3267)
- Madeleine I. Kenton (ORCID: https://orcid.org/0000-0002-9214-6589)
- Aurora Kraus (ORCID: https://orcid.org/0000-0002-1417-5165)
- Lucas Blevens (ORCID: https://orcid.org/0009-0007-1780-4055)
- Van N. Pham (ORCID: https://orcid.org/0009-0005-1065-6649)
- Christopher W. Dell (ORCID: https://orcid.org/0000-0002-6563-697X)
Institutions
- Smithsonian Institution (US)
- National Institutes of Health (US)
- National Museum of Natural History (US)
- University of Wisconsin–Madison (US)
- University of Alberta (CA)
- Frederick National Laboratory for Cancer Research (US)
- National Cancer Institute (US)
- Eunice Kennedy Shriver National Institute of Child Health and Human Development (US)
- Center for Cancer Research (US)
- University of Oklahoma Health Sciences Center (US)
Publication Details
- Journal
- The Journal of Experimental Medicine
- Published
- 2025-04-01
- DOI
- https://doi.org/10.1084/jem.20241435
- Citations
- 6
- Primary Topic
- Zebrafish Biomedical Research Applications
- Type
- article
- Field-Weighted Citation Impact
- 6.91
Funders
- National Institutes of Health
- National Museum of Natural History
- University of Oklahoma Health Sciences Center
- Canadian Institutes of Health Research
- National Cancer Institute
- National Institute of Child Health and Human Development
- Hyundai Hope On Wheels