Functional Roles of Immune Cells in Fish Against Bacterial and Viral Infections

Defense strategies of fish have always been of particular interest because these species are constantly exposed to the various and abundant microbes in the aquatic habitat. The immune system is a biological process that can identify a variety of substances in vitro, such as bacteria, viruses, parasites, or abnormal substances, distinguishing them from healthy cells and tissues in vivo. The immune system comprises various types of immune cells, including monocytes/macrophages, granulocytes, and natural killer cells, which participate in innate immunity, as well as B and T cells, which are involved in adaptive immunity. The mutual interaction and regulation of these immune cells constitute a pivotal part of the immune system. Therefore, in-depth exploration and elucidation of the functions of immune cells in fish play an indispensable role in resisting the invasion of pathogenic microorganisms and maintaining homeostasis.

In this Research Topic, we aim to focus on articles that discuss the identification of immune cells, their interactions with bacterial and viral pathogens, pathogen recognition receptors, intracellular signaling pathways, and the mutual regulation of immune cells in fish. Our goal is to achieve a comprehensive understanding of the role of immune cells in helping fish resist pathogen infections and adapt to their environment.

This Research Topic will be dedicated to an overview of recent progress in the study of the functional roles of immune cells in fish against bacterial and viral infections, including but not limited to:

1. Identification of diversity in immune cell populations
2. Role of immune cells in mucosal immunity
3. Mutual regulation among immune cells
4. Signaling pathways of pathogen recognition receptors
5. Similarities and differences in the mechanisms of immune cell action

Contributions could be in the form of original research, review articles, and short reports.