Table 9.

Frequently measured immune parameters in finfish studies.

Immune parameters	Functions	References
Antibody	Produced by B cells Recognizes and binds to specific antigens of pathogens Neutralization of pathogens Opsonization of antibody bound pathogens Activation of the complement system Activation of antibody-dependent cellular cytotoxicity	Abbas et al., 2014
Cytokine	Signal proteins of host cells Activation of inflammation through proinflammatory cytokines (eg., IL-1β, INF-γ, TNF-α) Regulation of immune activities/anti-inflammation through regulatory cytokines (eg., IL-10, TGF-β)	Wang and Secombes, 2013; Abbas et al., 2014; Turner et al., 2014
Complement activity	Non-cellular immune response which is activated by antigen-specific antibodies or lectin Formation of membrane attack complexes (MAC) of the surface of pathogens Induction of inflammation at local infection sites Opsonization of pathogens by antibody binding or complement subunits to the surface of pathogens	Alexander and Ingram, 1992; Abbas et al., 2014
Lysozyme	Non-cellular immune response toward bacterial pathogens Hydrolysis β-(1, 4) glycosidic linkages in N-acetylmuramic acid and N-acetylglucosamine of bacterial cell wall peptidoglycan	Alexander and Ingram, 1992
Phagocytosis	Engulfing activity of phagocytic cells such as dendritic cells, macrophages, and monocytes Direct killing of pathogen by intracellular lysosome of phagocytic cells Antigen presentation of phagocytosed antigens to T cell by dendritic cells and macrophages	Abbas et al., 2014
Respiratory burst	Oxidative potential of innate cells Pathogen killing effect by reactive oxygen species including hydrogen peroxide, superoxide anions, and hydroxyl radicals	Abbas et al., 2014