A Leukocyte Immune-Type Receptor Subset Is a Marker of Antiviral Cytotoxic Cells in Channel Catfish, Ictalurus punctatus

Abstract

Channel catfish, Ictalurus punctatus, leukocyte immune type receptors (LITRs) represent a multigene family that encodes Ig superfamily proteins that mediate activating or inhibitory signaling. In this study, we demonstrate the use 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 CTLs. 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 5 d after primary immunization with G14D-CCV and at 3 d after a booster immunization as compared with 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 CD3γδ, 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, to our knowledge for the first time, functional characterization of LITRs in an autologous system. In addition, the identification of an LITR subset as a cytotoxic cell marker will allow for more effective monitoring of catfish immune responses to pathogens.

Spotted Gar and the Evolution of Innate Immune Receptors

“…FcR‐like molecules, which are found in mammals and teleost fish, are readily identifiable in gar (e.g., ENSLOCG00000009857, ENSLOCG00000009867, ENSLOCG00000009848, ENSLOCG00000000344, ENSLOCG00000000699, and ENSLOCG00000000629) and dispersed throughout the gar genome (LG3, LG5, and one unplaced scaffold). As mentioned above, it is unclear if definitive orthologs of the teleost LITR gene family, a subset of which are markers for cytotoxic T cells (Taylor et al., ), are present in gar. Transcripts encoding inhibitory and activating LITRs have been described extensively in catfish (Stafford et al., , ) and LITR Ig domains can be identified in the zebrafish genome (Rodríguez‐Nunez et al., ).…”

Multidimensional quantitative analysis of mRNA expression within intact vertebrate embryos

“…Current approaches employ some combination of microdissection (Nawshad et al, 2004;Redmond et al, 2014;Treutlein et al, 2014), cell dissociation (Manoli and Driever, 2012;Jean et al, 2015;Petropoulos et al, 2016), homogenization (Axelsson et al, 2007;de Jong et al, 2010;Pena et al, 2014), fluorescenceactivated cell sorting (Manoli and Driever, 2012;Treutlein et al, 2014;Allison et al, 2016), magnetic-activated cell sorting (Treutlein et al, 2014;Allison et al, 2016;Taylor et al, 2016) or lysis (Nawshad et al, 2004;de Jong et al, 2010;Laranjeiro and Whitmore, 2014;Redmond et al, 2014;Treutlein et al, 2014;Jean et al, 2015;Allison et al, 2016;Petropoulos et al, 2016), followed by RNA quantitation using quantitative real-time polymerase chain reaction (qPCR) (Nawshad et al, 2004;Axelsson et al, 2007;Laranjeiro and Whitmore, 2014;Pena et al, 2014;Jean et al, 2015), RNA sequencing (Treutlein et al, 2014;Allison et al, 2016;Petropoulos et al, 2016), in situ hybridization flow cytometry (Allison et al, 2016;Taylor et al, 2016), microarray hybridization (de Jong et al, 2010;Redmond et al, 2014;Jean et al, 2015) or hybridization barcoding (Laranjei...…”

Molecular characterization of three novel perforins in common carp (Cyprinus carpio L.) and their expression patterns during larvae ontogeny and in response to immune challenges

“…In humans and mice, perforin is a single-copy gene, and presently its immunological function has been well studied. In teleosts, until now, the perforin genes have been characterized in 6 species, including Japanese flounder ( Paralichtys olivaceus ) [ 15 , 16 ], channel catfish ( Ictalurus punctatus ) [ 17 ], rainbow trout ( Oncorhynchus mykiss ) [ 18 ], ginbuna crucian carp ( Carassius auratus langsdorfii ) [ 19 ], rock bream ( Oplegnathus fasciatus ) [ 20 , 21 ] and zebrafish ( Danio rerio ) [ 22 ]. Moreover, different with humans and mice, there are more than one perforin genes in fish genomes [ 19 , 22 ], although only one isoform was reported in some teleosts to date [ 16 – 18 , 20 ].…”