CD80/86分子是重要的共刺激配体之一,通过与CD28连接,然后将所需的第二信号传递给T细胞活化,从而涉及抗原特异性免疫应答。在这项研究中,确定了CD80/86同源物,并研究了其在比目鱼(Paralichthysolivaceus)中的表达特征。CD80/86的开放阅读框(ORF)为906bp,编码301aa,和细胞外氨基酸序列编码两个IgV和IgC样结构域;fCD80/86在头肾中高表达,外周血白细胞(PBLs),和脾脏,并且在肌肉中具有相对较高的表达。产生CD80/86特异性抗体,CD80/86与MHCII+共定位,CD40+,和CD83+白细胞,但不是IgM+,CD3+,或CD4+淋巴细胞。比目鱼中克隆的CD80/86与其哺乳动物对应物具有保守的结构特征,并且主要分布在抗原呈递细胞上。基于这些数据,研究了CD80/86作为佐剂增强DNA疫苗的免疫应答。成功构建了同时表达CD80/86和弧菌外膜蛋白(OmpK)(p-OmpK-CD80/86)的双顺反子DNA疫苗。免疫接种后,p-OmpK-CD80/86可诱导比目鱼IgM+和CD4+细胞比例上调,与p-OmpK或p-CD80/86免疫组相比;CD28基因在p-CD80/86和p-OmpK-CD80/86组中被显著诱导。与p-OmpK组相比,在注射部位检测到较高的CD83,MHCI,CD4,CD8和IL-2表达.p-OmpK-CD80/86产生的相对存活率(RPS)为66.11%,而p-OmpK或p-CD80/86的RPS分别为46.30%和5.56%,分别。结果表明,CD80/86主要存在于抗原呈递细胞中,并且可以通过涉及CD4淋巴细胞的CD80/86-CD28信号通路帮助引起硬骨鱼的体液免疫反应。
The CD80/86 molecule is one of the important co-stimulatory ligands and involves antigen-specific immune responses by ligating with CD28 and then delivering the required second signal to T-cell activation. In this study, a CD80/86 homolog was identified, and its expression characteristics were studied in flounder (Paralichthys olivaceus). The open reading frame (ORF) of CD80/86 is 906 bp, encoding 301 aa, and the extracellular amino acid sequence encoded two IgV- and IgC-like structural domains; fCD80/86 is highly expressed in head kidney, peripheral blood leukocytes (PBLs), and spleen, and has relatively high expression in muscle. Antibodies specific for CD80/86 were produced, and CD80/86 was colocalized with MHCII+, CD40+, and CD83+ leukocytes but not with IgM+, CD3+, or CD4+ lymphocytes. The cloned CD80/86 in flounder shares conserved structural features with its mammalian counterparts and is mainly distributed on antigen-presenting cells. Based on these data, CD80/86 as an adjuvant to enhance the immune response of DNA vaccine was investigated. A bicistronic DNA vaccine expressing both CD80/86 and the outer membrane protein (OmpK) of Vibrio anguillarum (p-OmpK-CD80/86) was successfully constructed. After immunization, p-OmpK-CD80/86 could induce the upregulation of the proportion of IgM+ and CD4+ cells in flounder, compared to the p-OmpK- or p-CD80/86-immunized group; CD28 genes were significantly induced in the p-CD80/86 and p-OmpK-CD80/86 groups. Compared to the p-OmpK group, the higher expression of CD83, MHCI, CD4, CD8, and IL-2 was detected at the injection site. The relative percent survival (RPS) produced by p-OmpK-CD80/86 is 66.11% following the V. anguillarum challenge, while the RPS of p-OmpK or p-CD80/86 is 46.30% and 5.56%, respectively. The results revealed that CD80/86 is mainly found in antigen-presenting cells, and could help elicit humoral immune responses in teleost through the CD80/86-CD28 signaling pathway involving CD4+ lymphocytes.