采用RACE-PCR方法,从鲢(Hypophthalmichthys molitrix)头肾SMARTcDNA中获得了679 bp IL-8 cDNA序列。结果显示:该序列包含169 bp的5′非编码区,213 bp 3′端非编码区和297 bp的开放阅读框;鲢IL-8的开放阅读框编码98个氨基酸残基,其中包含构成两对二硫键的4个保守半胱氨酸。RT-PCR结果显示鲢:IL-8 mRNA主要在胰、肝脏和头肾中表达。将鲢IL-8不含信号肽的成熟多肽克隆到原核融合表达载体pQE30上,转入大肠杆菌M15内进行表达,经SDS-PAGE电泳后显示,重组融合蛋白在分子量约11kD处有一明显表达带,与预期计算的分子量大小相一致。
The genomic and cDNA sequences of the CD3γ/δ and CD3ε homologues in the mandarin fish, Siniperca chuatsi, were determined. As in other vertebrate CD3 molecules, the deduced amino acid sequences of mandarin fish CD3γ/δ and CD3ε contained conserved residues and motifs, such as cysteine residues and CXXC and immunoreceptor tyrosine-based activation motifs. However, mandarin fish CD3γ/δ and CD3ε showed some differences to their mammalian counterparts, specifically the absence of a negatively charged residue in the transmembrane region of CD3γ/δ. Additionally, while an N-glycosylation site was present in CD3c, the site was not observed in CD3γ/δ. The CD3γ/δ and CD3ε subunit sequences contain six and five exons, respectively, consistent with homologues from Atlantic salmon, Salmo salar. Phylogenetic analysis also revealed that CD3γ/δ and CD3ε in mandarin fish are closely related to their counterparts in Acanthopterygian fish. Real-time PCR showed CD3γ/δ and CD3ε were expressed mainly in the thymus and spleen in normal healthy fish and, to a lesser extent, in mucosal-associated lymphoid tissues, such as the intestine and gills. When lymphocytes isolated from head kidney were treated with the mitogens phytohemagglutinin, concanavalin, and polyriboinosinic polyribocytidylic acid, mRNA expression levels of CD3γ/δ and CD3ε were significantly elevated within 12 h of treatment. This indicated the presence of T lymphocytes in the head kidney of teleost fish, and also the recognition of mitogens by the lymphocytes. Mandarin fish infected with the bacterial pathogen Flavobacterium columnare also showed an increase in the expression of CD3γ/δ and CD3ε mR_NA, indicating that CD3γ/δ and CD3ε lymphocytes are involved in the immune response of this species.
肿瘤坏死因子（TNF）是一种炎症细胞因子，在非特异性免疫系统中发挥着重要作用。TNF由单核细胞或巨噬细胞产生，能直接造成肿瘤细胞的死亡，并参与机体炎症和免疫应答的调节。用RACE（rapid amplification of cDNA ends）-PCR方法，从鲢总RNA反转录产物中获得了1254 bp TNF cDNA全序列。该序列包含394bp的5’端非编码区，398 bp的3’端非编码区和462bp的开放阅读框。鲢TNF的开放阅读框编码239个氨基酸，其中包含构成一对二硫键的2个保守半胱氨酸。同时利用RT-PCR技术，对该基因在鲢鱼体内不同组织之间的表达差异进行了分析研究，结果表明鲢TNF mRNA主要在脑、鳃和头肾中表达，肠和脾中有少量表达，而在肝中几乎没有表达。
