Evolutionary perspective on the hematopoietic system through a colonial chordate: allogeneic immunity and hematopoiesis. (February 2020)

• Record Type: Journal Article
• Authors: Rosental, Benyamin; Raveh, Tal; Voskoboynik, Ayelet; Weissman, Irving L
• Is Part Of: Current opinion in immunology. Volume 62(2020)
• Page Start: 91
• Page End: 98
• Publication Date: 2020-02
• Subjects: Immunology -- Periodicals; Allergy -- Periodicals; Immunology -- Abstracts -- Periodicals; Allergy -- Abstracts -- Periodicals; 616.079
• DOI: 10.1016/j.coi.2019.12.006
• Languages: English
• ISSNs: 0952-7915

Abstract

Highlights: Botryllus schlosseri HSCs have been isolated and their niche identified. Mammalian and B. schlosseri HSCs and their respective niches share many homologous transcripts. Cytotoxicity is the mechanism of immune allogeneic cellular rejection. Botryllus Histocompatibility Factor (BHF) determines fusion or rejection of colonies. Allogeneic rejection by cytotoxic cells is inhibited by BHF, similar to NK cells. Abstract : Evolution and selection have shaped diverse immune systems throughout phylogeny, the vast majority of which remain unexplored. Botryllus schlosseri is a colonial tunicate, a sister group to vertebrates, that develops as a chordate, then metamorphoses to an asexually reproductive invertebrate that every week makes the same body plan from budded stem cells. Genetically distinct B. schlosseri colonies can fuse to form a chimera, or reject each other based on allogeneic recognition. In chimeras, circulating germline and somatic stem cells participate in development; stem cells compete in all individuals in the fused colonies, with rejection preventing germline parasitism. Here we review the isolation and characterization of B. schlosseri hematopoietic stem cells (HSC) and their niches, and the role of the immune effector cells in allorecognition.