Lymphocytes with T-cell-like properties express the Fas ligand in the Japanese flounder Paralichthys olivaceus.
In this study, we aimed to identify the leukocyte population that expresses Fas ligand (FasL) in the Japanese flounder (Paralichthys olivaceus). The transcriptional activity of FasL was examined for the first time in the fish leukocytes. Transcription of the FasL gene in flounder leukocytes was significantly increased by phytohemagglutinin (PHA) treatment. All the leukocyte populations we tested possessed binding activity for PHA, but this was especially high in the lymphocyte population. However, the lymphocytes consisted of two subsets showing heterogeneity with respect to PHA binding, with the high-binding subset being surface IgM-negative. We also found that only the lymphocyte population showed a significant increase in the expression of the FasL gene after stimulation with PHA. In addition, only the lymphocyte subset showing high binding to PHA showed conspicuous expression of the FasL gene. This subset also had a CD3γ/δ+, CD8α+ and IgM heavy-chain (-) phenotype. These results suggested that lymphocytes with T-cell-like properties are FasL-expressing cells in the Japanese flounder.
Laboratory of Fish Diseases, Department of Veterinary Science, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino, Tokyo 180-8602, Japan. kurata@nvlu.ac.jp
Osamu
O
Kurata
Toru
T
Iwasaki
Tomomasa
T
Matsuyama
Chihaya
C
Nakayasu
Shinpei
S
Wada
Kishio
K
Hatai
D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D053222:Fas Ligand Protein / Q000276:immunology*; D005432:Flounder / Q000276:immunology*; D005786:Gene Expression Regulation / Q000187:drug effects; D008214:Lymphocytes / Q000276:immunology*; D010835:Phytohemagglutinins / Q000276:immunology; D011485:Protein Binding; D013601:T-Lymphocytes / Q000276:immunology*
D000276:Adjuvants, Immunologic; D053222:Fas Ligand Protein; D010835:Phytohemagglutinins