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ARS Home » Southeast Area » Stoneville, Mississippi » Warmwater Aquaculture Research Unit » Research » Publications at this Location » Publication #322713
Title: A leukocyte immune-type receptor (LITR) subset is a marker of antiviral cytotoxic cells in channel catfish, Ictalurus punctatus

Author
item TAYLOR, ERIN - University Of Mississippi Medical Center
item MOULANA, MOHADETHEH - University Of Mississippi Medical Center
item STUGE, T - The University Of Tromsø
item Quiniou, Sylvie
item EVA, BENGTEN - University Of Mississippi Medical Center
item WILSON, MELANIE - University Of Mississippi Medical Center

Submitted to: Journal of Immunology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2016
Publication Date: 3/15/2016
Citation: Taylor, E.B., Moulana, M., Stuge, T., Quiniou, S., Eva, B., Wilson, M. 2016. A leukocyte immune-type receptor (LITR) subset is a marker of antiviral cytotoxic cells in channel catfish, Ictalurus punctatus. Journal of Immunology. 196(6):2677-2689.

Interpretive Summary: Leukocyte immune type-receptors (LITRs) represent a multigene family specific to fish. In this study a monoclonal antibody (CC41) is shown to react with a subset of the catfish LITR molecules. Also, the percent of cells reacting with CC41 increase after immunization and when purified those cells demonstrate killing capacities. Therefore the CC41 antibody can now be used to monitor the catfish cytotoxic cell response to pathogens.

Technical Abstract: Channel catfish, Ictalurus punctatus, leukocyte immune type-receptors (LITRs) represent a multigene family that encodes immunoglobulin superfamily proteins that mediate activating or inhibitory signaling. Here we demonstrate the utility of mAb CC41 to monitor viral cytotoxic responses in catfish and determine that CC41 binds to a subset of LITRs on the surface of catfish clonal cytotoxic T lymphocytes (CTL). Homozygous gynogenetic catfish were immunized with channel catfish virus (CCV)-infected MHC-matched clonal T cells (G14D-CCV) and PBL were collected at various times after immunization for flow cytometric analyses. The percentage of CC41+ cells was significantly increased five days after primary immunization with G14D-CCV and at three days after a booster immunization as compared to control fish only injected with G14D. Moreover, CC41+ cells magnetically isolated from the PBL specifically killed CCV-infected targets as measured by 51Cr-release assays and expressed messages for CD3'd, perforin, and at least one of the CD4-like receptors as analyzed by RNA flow cytometry. When MLC effector cells derived from a G14D-CCV immunized fish were preincubated with CC41 mAb, killing of G14D-CCV targets was reduced by ~40%, suggesting that at least some LITRs have a role in target cell recognition and/or cytotoxicity. The availability of a LITR-specific mAb has allowed, for the first time, functional characterization of LITRs in an autologous system. Additionally, the identification of an LITR subset as a cytotoxic cell marker will allow for more effective monitoring of catfish immune responses to pathogens.