Cold-blooded vertebrates evolved organized germinal center-like structures.

ABSTRACT: Germinal centers (GCs) or analogous secondary lymphoid microstructures (SLMs) are thought to have evolved in endothermic species. However, living representatives of their ectothermic ancestors can mount potent secondary antibody responses upon infection or immunization, despite the apparent lack of SLMs in these cold-blooded vertebrates. How and where adaptive immune responses are induced in ectothermic species in the absence of GCs or analogous SLMs remain poorly understood. Here, we infected a teleost fish (trout) with the parasite Ichthyophthirius multifiliis (Ich) and identified the formation of large aggregates of highly proliferating IgM⁺ B cells and CD4⁺ T cells, contiguous to splenic melanomacrophage centers (MMCs). Most of these MMC-associated lymphoid

SUBMITTER: Shibasaki Y 

PROVIDER: S-EPMC11152321 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature