登革病毒高度保守的HLA-A*1101限制性T细胞表位鉴定和体内免疫反应研究

目的：鉴定登革病毒2型（DENV-2）HLA-A*1101限制性T细胞表位并探讨其诱导的T细胞反应的特征。方法：基于DENV-2的氨基酸序列，采用T细胞表位预测软件预测HLA-A*1101限制性候选T细胞表位；基于HLA-A*1101转基因小鼠，采用ELISPOT实验、ELISA实验和CD8+T细胞（CTL）杀伤实验研究候选表位的HLA-A*1101限制性和所诱导的T细胞反应的特征。结果：在合成的14条候选表位中，9条肽（NS1161-170、NS1263-272、NS36-15、NS4b44-53、NS333-42、C58-67、E30-38、NS3576-584和NS4a72-80）免疫HLA-A*1101转基因小鼠可诱导产生肽特异性分泌IFN-γ的T细胞。除了分泌IFN-γ，C58-67和NS3576-584特异性T细胞也可分泌TNF-α，而E30-38特异性T细胞更可同时分泌TNF-α和IL-6。DENV-2感染的HLA-A*1101转基因小鼠体内也可检测到针对NS4b44-53、NS333-42、C58-67、E30-38、NS3576-584和NS4a72-80的分泌IFN-γ的T细胞。采用上述6条肽的混合物免疫HLA-A*1101转基因小鼠所诱导的效应细胞可显著杀伤DENV-2感染的小鼠脾单核细胞。结论：本研究鉴定出了9条全新的DENV-2特异性HLA-A*1101限制性T细胞表位。

Identification of dengue virus-derived highly conserved HLA-A*1101-restricted T-cell epitopes and study on their in vivo immune responses

Objective: To identify dengue virus serotype 2 (DENV-2)-derived HLA-A*1101-restricted T-cell epitopes and explore the characteristics of induced T cells. Methods: Based on the complete amino acid sequence of DENV-2, T-cell epitope prediction software was utilized to predict putative HLA-A*1101-restricted T-cell epitope. Based on HLA-A*1101 transgenic mice, the HLA-A*1101 restriction of epitope candidates and the characteristics of induced T cells were determined using ELISPOT assay, ELISA assay and CTL cytotoxicity assay. Results: Among 14 epitope candidated, each of 9 peptide (NS1161-170, NS1263-272, NS36-15, NS4b44-53, NS333-42, C58-67, E30-38, NS3576-584, and NS4a72-80) could induce IFN-γ-secreting T cell response in HLA-A*1101 transgenic mice. Except for IFN-γ, C58-67 - and NS3576-584 -specific T cells also could secret TNF-α while E30-38-specific T cells could secret TNF-α and IL-6 simultaneously. High levels of IFN-γ-secreting T cells were detected in DENV-2-infected HLA-A*1101 transgenic mice and directed to 6 peptides (NS4b44-53, NS333-42, C58-67, E30-38, NS3576-584, and NS4a72-80). The effector cells from HLA-A*1101 transgenic mice immunized with the mixture of 6 above-mentioned peptides efficiently lysed DENV-2-infected splenic monocytes. Conclusion: Nine DENV-2-derived peptides are identified as HLA-A*1101-restricted T-cell epitopes.