Fiorito F, Pagnini U, De Martino L, Montagnaro S, Ciarcia R, Florio S, Pacilio M, Fucito A, Rossi A, Iovane G, Giordano A
Department of Pathology and Animal Health, Naples, Italy.
J Cell Biochem. 2008 Jan 1;103(1):221-33. doi: 10.1002/jcb.21398.
Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental toxin of current interest. In the last years, higher levels of TCDD than those permitted in UE [European Commission. 2002. European Commission Recommendation 2002/201/CE. Official Gazette, L 67/69] were detected in milk samples from cow, water buffalo, goat, and sheep raised on some areas of Campania Region (South Italy). Dioxin often causes immunosuppression and might render the animal liable to viral infections. In addition, viral infections are able to alter the pattern of dioxin distribution in different organs of the exposed animals. Bovine Herpesvirus type-1 (BHV-1) is a widespread pathogen, which causes infectious rhinotracheitis and infectious pustular vulvovaginitis in cattle. Herein, we have studied the effects of TCDD and BHV-1 infection, in Madin-Darby Bovine Kidney (MDBK) cells, alone as well as in association, so as cellular proliferation, apoptosis, and virus replication. We have observed an increase in cell viability of confluent monolayers at low TCDD concentrations. TCDD treated cells demonstrated increased viability compared to controls as evaluated by MTT test. TCDD exposure increased cell proliferation but induced no changes on apoptosis. Cells exposed to TCDD along with BHV-1 showed a dose-dependent increase in cytopathy, represented by ample syncytia formation with the elimination of the cellular sheets and increased viral titer. These results suggest that TCDD increases viral replication in MDBK cells while BHV-1 further decreases viability of TCDD exposed cells. Since very low concentrations (0.01 pg/ml) are sufficient to augment BHV-1 titer, TCDD may contribute to reactivate BHV-1 from latency, leading to recurrent disease and increase virus transmission.
二噁英 - 2,3,7,8 - 四氯二苯并 - p - 二噁英（TCDD）是一种当前备受关注的常见环境毒素。在过去几年中，在意大利南部坎帕尼亚地区某些区域饲养的奶牛、水牛、山羊和绵羊的牛奶样本中，检测到的TCDD水平高于欧盟允许的水平[欧盟委员会。2002年。欧盟委员会第2002/201/CE号建议。官方公报，L 67/69]。二噁英通常会导致免疫抑制，并可能使动物易患病毒感染。此外，病毒感染能够改变二噁英在受感染动物不同器官中的分布模式。牛疱疹病毒1型（BHV - 1）是一种广泛传播的病原体，可引起牛的传染性鼻气管炎和传染性脓疱性外阴阴道炎。在此，我们研究了TCDD和BHV - 1感染单独以及联合作用对马 - 达氏牛肾（MDBK）细胞的影响，包括细胞增殖、凋亡和病毒复制。我们观察到在低TCDD浓度下，汇合单层细胞的细胞活力增加。通过MTT试验评估，与对照相比，TCDD处理的细胞显示出活力增加。TCDD暴露增加了细胞增殖，但对凋亡没有诱导变化。同时暴露于TCDD和BHV - 1的细胞表现出细胞病变呈剂量依赖性增加，表现为形成大量多核巨细胞，细胞单层消失且病毒滴度增加。这些结果表明，TCDD增加了MDBK细胞中的病毒复制，而BHV - 1进一步降低了TCDD暴露细胞的活力。由于极低浓度（0.01 pg/ml）就足以提高BHV - 1滴度，TCDD可能有助于使潜伏的BHV - 1重新激活，导致疾病复发并增加病毒传播。
