Durand S V M, Hulst M M, de Wit A A C, Mastebroek L, Loeffen W L A
Central Veterinary Institute of Wageningen University and Research Centre, P.O. Box 65, 8200 AB, Lelystad, The Netherlands.
Arch Virol. 2009;154(9):1417-31. doi: 10.1007/s00705-009-0460-3. Epub 2009 Aug 2.
The immune response to CSFV and the strategies of this virus to evade and suppress the pigs' immune system are still poorly understood. Therefore, we investigated the transcriptional response in the tonsils, median retropharyngeal lymph node (MRLN), and spleen of pigs infected with CSFV strains of similar origin with high, moderate, and low virulence. Using a porcine spleen/intestinal cDNA microarray, expression levels in RNA pools prepared from infected tissue at 3 dpi (three pigs per virus strain) were compared to levels in pools prepared from uninfected homologue tissues (nine pigs). A total of 44 genes were found to be differentially expressed. The genes were functionally clustered in six groups: innate and adaptive immune response, interferon-regulated genes, apoptosis, ubiquitin-mediated proteolysis, oxidative phosphorylation and cytoskeleton. Significant up-regulation of three IFN-gamma-induced genes in the MRLNs of pigs infected with the low virulence strain was the only clear qualitative difference in gene expression observed between the strains with high, moderate and low virulence. Real-time PCR analysis of four response genes in all individual samples largely confirmed the microarray data at 3 dpi. Additional PCR analysis of infected tonsil, MRLN, and spleen samples collected at 7 and 10 dpi indicated that the strong induction of expression of the antiviral response genes chemokine CXCL10 and 2'-5' oligoadenylate synthetase 2, and of the TNF-related apoptosis-inducing ligand (TRAIL) gene at 3 dpi, decreased to lower levels at 7 and 10 dpi. For the highly and moderately virulent strains, this decrease in antiviral and apoptotic gene expression coincided with higher levels of virus in these immune tissues.
目前，人们对猪瘟病毒（CSFV）的免疫反应以及该病毒逃避和抑制猪免疫系统的策略仍知之甚少。因此，我们研究了感染来源相似、毒力分别为高、中、低的CSFV毒株的猪的扁桃体、咽后中淋巴结（MRLN）和脾脏中的转录反应。使用猪脾脏/肠道cDNA微阵列，将感染后3天（每个病毒株三头猪）感染组织制备的RNA池中的表达水平与未感染同源组织（九头猪）制备的RNA池中的表达水平进行比较。共发现44个基因存在差异表达。这些基因在功能上分为六组：先天性和适应性免疫反应、干扰素调节基因、细胞凋亡、泛素介导的蛋白水解、氧化磷酸化和细胞骨架。在感染低毒力毒株的猪的MRLN中，三个干扰素-γ诱导基因的显著上调是高、中、低毒力毒株之间观察到的唯一明显的基因表达定性差异。对所有个体样本中的四个反应基因进行实时PCR分析，在很大程度上证实了感染后3天的微阵列数据。对感染后7天和10天采集的扁桃体、MRLN和脾脏样本进行的额外PCR分析表明，抗病毒反应基因趋化因子CXCL10和2'-5'寡腺苷酸合成酶2以及TNF相关凋亡诱导配体（TRAIL）基因在感染后3天的强烈表达诱导，在感染后7天和10天降至较低水平。对于高毒力和中毒力毒株，抗病毒和凋亡基因表达的这种下降与这些免疫组织中更高水平的病毒同时出现。
