Novel techniques to identify immune cell population in fish

The immune system evolved to protect multicellular organisms from pathogens. In vertebrates, the immune response is composed of two interconnected arms: Innate immunity and Adaptive immunity. Cartilaginous/bony fish is the first evolutionary group that comprises both these arms. Thus, fish is considered as a supreme model for clarifying the evolution and regulatory mechanism of vertebrate immunity. Presently, cartilaginous/bony fish are reported to possess many hallmarks associated with mammalian immunity but have also adopted some unique strategies for immune cell development and elimination of threatening pathogens. Further, the characteristic cellular components of the innate immune system (including monocytes/macrophages, granulocytes, and natural killer cells) and the adaptive immune system (including B-like and T-like cells) are documented in fish. However, the knowledge of distinct immune cell populations in fish is still limited, and further development of tools (e.g., monoclonal antibodies to bony fish leukocytes), and techniques advancing the identification of fish immune cell populations (e.g., single cell RNA-seq and in situ hybridization techniques like RNAscope) and their functions (e.g., CRISPR-Cas) are required.

This Research Topic aims to gather a collection of articles on the novel techniques to identify immune cell population in fish to improve the understanding of the heterogeneity, development, function, and interaction networks of different fish immune cell populations. We hope that this collection will contribute to further investigation of innate and adaptive cellular immunity in fish and thereby increase present insight into the evolution of vertebrate immune system.

The research topic welcomes the submission of Original Research, Reviews, Mini-Reviews, and Methods which cover but are not limited to the following topics:
1. Novel techniques advancing the identification and characterization of fish immune cell populations
2. Novel tools (e.g. monoclonal antibodies for defining new markers of immune cells) improving the knowledge of distinct immune cell populations in fish
3. The diversity among individual cells of the alleged same immune cell type
4. The immunological responses within a single cell population upon different stimulations
5. The reconstruction of development of distinct immune cell subpopulations
6. The cross-talks between different immune cell populations
7. The functions and regulatory mechanisms of distinct immune cell subsets
8. Evolutionary and comparative perspectives of immune cell subsets

All submissions should address how the novel techniques and tools used in the authors’ research significantly contribute to the advancement and/or to the understanding of the phylogeny of fish immune cells or mechanisms of fish immune cells-mediated response to stimuli.