Activation of channel catfish (Ictalurus punctatus) T cells involves NFAT-like transcription factors.
Cyclosporin A (CsA) specifically inhibits mammalian T cells by preventing activation of transcription factors (termed nuclear factor of activated T cells (NFAT)) involved in cytokine gene expression. In this study, catfish peripheral blood lymphocytes (PBL) and antigen specific T cells were treated with CsA to gain insights into the intracellular processes involved in fish T cell activation. To this end, CsA was observed to inhibit the in vitro proliferation of Con A stimulated catfish PBL, and specific alloantigen stimulated T cells. However, the inhibitory effect of CsA on catfish T cells was obviated by treatment with Con A, antigen activation or culture supernatant from activated catfish T cells prior to the addition of CsA. The use of a phosphatase assay coupled with Western blot analysis employing a polyclonal antibody to mammalian NFAT indicated that CsA prevents the dephosphorylation and subsequent nuclear translocation of an NFAT-like molecule in catfish T cells. Finally, a nuclear protein selection protocol demonstrated that a catfish NFAT-like protein binds to a known murine IL-2 promoter sequence. These results suggest that cytokines are involved in the activation of teleost T cells, and argue that T cell activation processes are conserved over a wide phylogenetic distance.
Park
H
H
Department of Microbiology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
Zhou
H
H
Bengtén
E
E
Wilson
M
M
Chinchar
V G
VG
Clem
L W
LW
Miller
N W
NW
D000818:Animals; D015153:Blotting, Western; D000001:Calcimycin / Q000276:immunology; D003208:Concanavalin A / Q000276:immunology; D016572:Cyclosporine / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000276:immunology*; D007059:Ictaluridae / Q000276:immunology* / Q000378:metabolism; D007166:Immunosuppressive Agents / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000276:immunology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000276:immunology; D013936:Thymidine / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000276:immunology*
D004268:DNA-Binding Proteins; D007166:Immunosuppressive Agents; D008070:Lipopolysaccharides; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D003208:Concanavalin A; D000001:Calcimycin; D016572:Cyclosporine; D010744:Phosphoric Monoester Hydrolases; D013755:Tetradecanoylphorbol Acetate; D013936:Thymidine