ABSTRACT
Phagocytosis, pinocytosis, chemotaxis, and cytotoxicity are important immune-defense functions of leukocytes. Many studies confirm the role of immune cells from elasmobranch fishes participating in these important processes. Taken together, existing studies point to the multiple cell types 106participating in phagocytosis and pinocytosis, but with granulocytic cells primarily responsible for phagocytic and pinocytic activity in the elasmobranch immune system, although thrombocytes and lymphocytes appear to participate in phagocytosis to some degree. A macrophage-like effector cell appears to be responsible for spontaneous cytotoxicity, as well as cytotoxicity that is elicited with mitogen stimulation or that requires antibody-dependent mechanisms. A lymphoid-like cell appears to be involved in regulating spontaneous cytotoxicity through a mechanism that is temperature dependent. Chemotactic migration and accumulation of leukocytes have been observed in the elasmobranch immune system and appear to occur in response to complement or other chemoattractants, leading to induction of inflammatory processes.
