title: Cytotoxic activity generated from channel catfish peripheral blood leukocytes in mixed leukocyte cultures.
abstract: In previous work, lysis of allotargets was routinely observed with PBL from nonimmune channel catfish. In the work reported here, greatly increased (approximately 100-fold) cytotoxic responses were generated by stimulation of channel catfish PBL with irradiated cells of allogeneic cloned B cell lines in mixed leukocyte cultures (MLC). This increased cytotoxicity did not appear to be simply a consequence of cell proliferation since stimulation of catfish PBL proliferative responses with polyclonal mitogens did not result in increased lysis. Somewhat surprisingly, the MLC-generated cytotoxicity did not exhibit allospecificity; i.e., allogeneic targets from other fish were as susceptible to lysis as were the cells used as stimulators. This apparent lack of allospecificity in MLC-generated cytotoxicity was confirmed by "cold" target inhibition assays. However, autologous targets were not killed, clearly demonstrating that MLC-generated effectors could distinguish "self" from "nonself" at the level of lysis/recognition. Although their origin is unresolved, the MLC-generated effectors may be a source of highly enriched fish cytotoxic cells and thus facilitate directly addressing questions pertaining to the evolution of such cells.
authors.affiliation: Department of Microbiology, University of Mississippi Medical Center, Jackson 39216-4505, USA.
authors.forename: T B
authors.initials: TB
authors.lastname: Stuge
authors.forename: S H
authors.initials: SH
authors.lastname: Yoshida
authors.forename: V G
authors.initials: VG
authors.lastname: Chinchar
authors.forename: N W
authors.initials: NW
authors.lastname: Miller
authors.forename: L W
authors.initials: LW
authors.lastname: Clem
mesh_terms: D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic; D007059:Ictaluridae / Q000097:blood / Q000276:immunology*; D007519:Isoantigens / Q000276:immunology; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D007959:Lymphocyte Culture Test, Mixed
chemical_list: D007519:Isoantigens; D008070:Lipopolysaccharides; D003208:Concanavalin A