Halbur P G, Paul P S, Frey M L, Landgraf J, Eernisse K, Meng X J, Andrews J J, Lum M A, Rathje J A
Veterinary Diagnostic Laboratory, Iowa State University, Ames, USA.
Vet Pathol. 1996 Mar;33(2):159-70. doi: 10.1177/030098589603300205.
One hundred 4-week-old cesarean-derived colostrum-deprived pigs were inoculated with one of two different US porcine reproductive and respiratory syndrome virus (PRRSV) isolates (VR2385, VR2431) or the European Lelystad virus to detect and compare the location and amount of virus antigen. Interstitial pneumonia, myocarditis, lymphadenopathy, and encephalitis were consistently seen in all three groups; however, disease and lesions were more severe in the VR2385 group. Immunohistochemical evaluation of formalin-fixed tissues revealed virus antigen in alveolar macrophages in lungs of 22/25, 14/25, 14/25, and 0/25 of the VR2385, VR2431, Lelystad, and control pigs, respectively. Follicular macrophages and dendritic cells in the lymph nodes of 14/25, 10/25, 10/25, and 0/25 pigs from the VR2385, VR2431, Lelystad, and control groups, respectively, stained positive for virus antigen. Similar cells in the tonsils from 25/25, 21/25, 23/25, and 0/25 pigs from the VR2385, VR2431, Lelystad, and control groups, respectively, stained positive for virus antigen. Other tissues and cells in which virus antigen was detected included macrophages and endothelial cells in the heart, macrophages, and interdigitating cells in the thymus, macrophages and dendritic cells in the spleen and Peyer's patches, and macrophages in hepatic sinusoids, renal medullary interstitium, and adrenal gland. PRRSV persisted in macrophages in the lung, tonsil, lymph node, and spleen for at least 28 days. Significantly more PRRSV antigen was detected in the lung (P < 0.01), lymph nodes (P < or = 0.05), and tonsils (P < 0.05) of the VR2385 pigs than was detected in the same tissues of the VR2431 and Lelystad pigs. The cell types in which PRRSV antigen was detected and the distribution of PRRSV antigen-positive cells within particular tissues and organs were generally similar for the different virus inoculation groups despite differences in virulence of the isolates.
将100头4周龄剖腹产且未摄入初乳的仔猪接种两种不同的美国猪繁殖与呼吸综合征病毒（PRRSV）分离株（VR2385、VR2431）或欧洲莱利斯塔德病毒中的一种，以检测和比较病毒抗原的位置和数量。在所有三组中均持续观察到间质性肺炎、心肌炎、淋巴结病和脑炎；然而，VR2385组的疾病和病变更为严重。对福尔马林固定组织的免疫组织化学评估显示，VR2385组、VR2431组、莱利斯塔德组和对照组猪肺中肺泡巨噬细胞内病毒抗原的检出率分别为22/25、14/25、14/25和0/25。VR2385组、VR2431组、莱利斯塔德组和对照组猪中分别有14/25、10/25、10/25和0/25的猪淋巴结中的滤泡巨噬细胞和树突状细胞病毒抗原染色呈阳性。VR2385组、VR2431组、莱利斯塔德组和对照组猪中分别有25/25、21/25、23/25和0/25的猪扁桃体中的类似细胞病毒抗原染色呈阳性。检测到病毒抗原的其他组织和细胞包括心脏中的巨噬细胞和内皮细胞、胸腺中的巨噬细胞和交错突细胞、脾脏和派伊尔结中的巨噬细胞和树突状细胞，以及肝血窦、肾髓质间质和肾上腺中的巨噬细胞。PRRSV在肺、扁桃体、淋巴结和脾脏的巨噬细胞中持续存在至少28天。与VR2431组和莱利斯塔德组猪的相同组织相比，VR2385组猪的肺（P < 0.01）、淋巴结（P ≤ 0.05）和扁桃体（P < 0.
