An investigation using zebrafish genetically developed to remain transparent into adulthood by the laboratory of Anna Huttenlocher, MD, professor in the Division of Allergy, Immunology, and Rheumatology and in the Department of Medical Microbiology and Immunology, resulted in a recent publication by her advisee, post-doc researcher and microbiologist Tanner Robertson.
The study was published May 8, 2023, in the Proceedings of the National Academy of Sciences and titled “A tessellated lymphoid network provides whole-body T cell surveillance in zebrafish.”
While examining T cells in the zebrafish, Robertson observed how the pools of T cells surveilled the body of the zebrafish by organizing into “a previously undescribed whole-body lymphoid network that supports streaming migration and coordinated trafficking” through the fish’s body. Thus, though fish and other non-mammalian jawed vertebrates lack lymph nodes that move T cells through mammals’ bodies, the zebrafish showed its T cell pools arranging themselves into networks that moved through the body, both surveilling and quickly interacting through collective migration with infection.
As stated in the abstract, “Our results reveal that T cells can toggle between collective migrations and individual random walks to prioritize whole-body T cell trafficking and antigen surveillance in the absence of a lymph node system.” Thus, the T cells of non-mammalian animals lacking a lymph node system, such as fish, birds, and reptiles, are able to function as effectively as those of mammals through a completely different modus operandi.
The published study includes short videos of real-time movement and network coordination of the tracked immune cells made visible through fluorescent proteins traveling through the fish.
UW–Madison University Communications published “In a first, researchers image adaptive immune systems at work in fish” on June 15, 2023.