Endoderm-Derived Myeloid-like Metaphocytes in Zebrafish Gill Mediate Soluble Antigen-Induced Immunity
Xi Lin,
Qiuxia Zhou,
Guanzhen Lin,
Changlong Zhao,
Zilong Wen
Affiliations
Xi Lin
Division of Life Science, State Key Laboratory of Molecular Neuroscience and Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
Qiuxia Zhou
Division of Life Science, State Key Laboratory of Molecular Neuroscience and Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
Guanzhen Lin
Division of Life Science, State Key Laboratory of Molecular Neuroscience and Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
Changlong Zhao
Division of Life Science, State Key Laboratory of Molecular Neuroscience and Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
Zilong Wen
Division of Life Science, State Key Laboratory of Molecular Neuroscience and Center of Systems Biology and Human Health, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen Peking University–Hong Kong University of Science and Technology Medical Center, Shenzhen 518055, China; Corresponding author
Summary: Immune cells in the mucosal barriers of vertebrates are highly heterogeneous in their origin and function. This heterogeneity is further exemplified by the recent discovery of ectoderm-derived immune cells—metaphocytes in zebrafish epidermis. Yet, whether non-hematopoiesis-derived immune cells generally exist in barrier tissues remains obscured. Here, we report the identification and characterization of an endoderm-derived immune cell population in the gill and intestine of zebrafish. Transcriptome analysis reveals that the endoderm-derived immune cells are myeloid-like cells with high similarities to the ectoderm-derived metaphocytes in epidermis. Like metaphocytes in epidermis, the endoderm-derived immune cells are non-phagocytic but professional in external soluble antigen uptake. Depletion of the endoderm-derived immune cells in gill hinder the local immune response to external soluble stimulants. This study demonstrates a general existence of non-hematopoiesis-derived immune cells in zebrafish mucosal barriers and challenges the prevalent view that resident immune cells in mucosal barriers arise exclusively from hematopoiesis.
