Acute resolving woodchuck hepatitis virus (WHV) infection is associated with a strong cytotoxic T-lymphocyte response to a single WHV core peptide
Acute resolving woodchuck hepatitis virus (WHV) infection is associated with a strong cytotoxic T-lymphocyte response to a single WHV core peptide
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DOI：
10.1128/jvi.02711-06
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发表时间：
2007-07-01
影响因子：
5.4
通讯作者：
Roggendorf, Michael
中科院分区：
文献类型：
--
作者：
Frank, Ina;Budde, Claudia;Roggendorf, Michael
感染土拨鼠肝炎病毒（WHV）的土拨鼠是研究急性、自限性和慢性嗜肝DNA病毒感染的极好模型。导致慢性病的免疫反应缺陷仍然未知。特异性T辅助细胞对WHV核心和表面抗原（分别为WHcAg和WHsAg）的反应与急性消退感染相关;然而，在慢性感染中无法检测到。到目前为止，细胞毒性T淋巴细胞（CTL）反应不能确定在土拨鼠。在本研究中，我们检测病毒特异性CTL反应的CD 107 a脱粒试验。分离WHV感染后急性期（感染后18个月）土拨鼠脾细胞，并用覆盖整个WHcAg的重叠肽刺激。6天后，再刺激细胞并对CD 3和CD 107 a染色。一种肽（c96-110）被证明是T细胞扩增和CD 107 a染色的原因。随后，我们应用优化的脱粒试验来研究急性WHV感染中T细胞应答的动力学。我们发现了一个有力的T细胞反应对肽c96-110与外周血细胞开始在病毒载量的峰值（第5周），并持续长达15周感染后。相反，在慢性WHV感染的动物中没有检测到针对肽c96-110的T细胞应答。因此，与这个新建立的流式细胞仪脱粒试验，我们首次检测到病毒特异性CTL，并确定了一个免疫优势表位的WHcAg在土拨鼠。
Woodchucks infected with woodchuck hepatitis virus (WHV) are an excellent model for studying acute, self-limited and chronic hepadnaviral infections. Defects in the immunological response leading to chronicity are still unknown. Specific T-helper cell responses to WHV core and surface antigens (WHcAg and WHsAg, respectively) are associated with acute resolving infection; however, they are undetectable in chronic infection. Up to now, cytotoxic T-lymphocyte (CTL) responses could not be determined in the woodchuck. In the present study, we detected virus-specific CTL responses by a CD107a degranulation assay. The splenocytes of woodchucks in the postacute phase of WHV infection (18 months postinfection) were isolated and stimulated with overlapping peptides covering the whole WHcAg. After 6 days, the cells were restimulated and stained for CD3 and CD107a. One peptide (c96-110) turned out to be accountable for T-cell expansion and CD107a staining. Later, we applied the optimized degranulation assay to study the kinetics of the T-cell response in acute WHV infection. We found a vigorous T-cell response against peptide c96-110 with peripheral blood cells beginning at the peak of viral load (week 5) and lasting up to 15 weeks postinfection. In contrast, there was no T-cell response against peptide c96-110 detectable in chronically WHV-infected animals. Thus, with this newly established flow cytometric degranulation assay, we detected for the first time virus-specific CTLs and determined one immunodominant epitope of WHcAg in the woodchuck.