Expression profiles of TCRbeta and CD8alpha mRNA correlate with virus-specific cell-mediated cytotoxic activity in ginbuna crucian carp.
Our previous studies have demonstrated that virus-specific cell-mediated cytotoxicity of sensitized leukocytes can be induced using clonal ginbuna crucian carp and their syngeneic cell lines. In the present study, we attempt to determine if virus-specific cytotoxic cell populations of fish express CD8alpha and TCRbeta genes. Leukocytes from ginbuna crucian carp were separated into four fractions by immunomagnetic separation and density gradient centrifugation: Fraction A, leukocytes with a density of 1.08 g/ml (primarily lymphocytes); Fraction B, sIg-negative leukocytes with density of 1.08 g/ml; Fraction C, sIg-positive cells (primarily B-lymphocytes); Fraction D, leukocytes with a density of 1.08-1.09 g/ml (primarily neutrophils). Leukocytes in all fractions from uninfected fish do not exhibit cytotoxic activity against virus-infected syngeneic cells and weakly express CD8alpha and TCRbeta mRNAs. In contrast, leukocytes in fractions A and B from virus-infected fish exhibit a high level of cytotoxic activity and strongly express CD8alpha and TCRbeta mRNAs. In addition, mRNA expressions of CD8alpha and TCRbeta in effector cells are upregulated by cocultivation with virus-infected target cells but not uninfected ones. The present study suggests that fish possess virus-specific cytotoxic cells with phenotype and gene expression pattern similar to those of CTLs in mammals.
Somamoto
Tomonori
T
Inland Station, National Research Institute of Aquaculture, FRA, Mie, Japan. somamoto@agr.kyushu-u.ac.jp
Yoshiura
Yasutoshi
Y
Sato
Atsushi
A
Nakao
Miki
M
Nakanishi
Teruyuki
T
Okamoto
Nobuaki
N
Ototake
Mitsuru
M
D000818:Animals; D001483:Base Sequence; D016827:CD8 Antigens / Q000235:genetics*; D002460:Cell Line; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D019674:Genes, T-Cell Receptor beta; D006054:Goldfish / Q000235:genetics / Q000276:immunology* / Q000821:virology*; D007962:Leukocytes / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D012209:Rhabdoviridae / Q000276:immunology*
D016827:CD8 Antigens; D018076:DNA, Complementary; D012333:RNA, Messenger