Fetal rhesus monkeys of either immune or nonimmune dams were given dual intraamniotic and subcutaneous inoculations of simian adenovirus SV-20 (AdSV-20). Fetuses of nonimmune dams were in two approximate age groups, 90 to 100 (n = 12) or 120 to 130 (n = 7) days gestation when inoculated. In 90- to 100-day fetuses, no AdSV-20-induced lesions were evident 3 days postinoculation, but on days 6 and 7 there was necrotizing bronchiolitis. Diffuse necrosis was present in the developing regions of the lung on days 10 and 12; however, an inflammatory cell response was limited. From 6 to 12 days, AdSV-20 antigens were demonstrable in pulmonary epithelial cells by indirect immunofluorescence staining. Paracrystalline arrays of adenoviruses were demonstrated by electron microscopy, always within undifferentiated epithelial cells. One fetus inoculated at 100 days died following delivery at term because of gross pulmonary hypoplasia which was characterized histologically by massive necrosis of pulmonary parenchyma. Fetuses of nonimmune dams inoculated between 120 and 130 days of gestation developed bronchiolar pneumonia with similar distribution of AdSV-20 antigens and virions as noted in those inoculated at 90 to 100 days. Lesions in these older fetuses were characterized by presence of more neutrophils than those in 90- to 100-day fetuses. Additionally, lymphoid hyperplasia with precocious development of germinal centers in bronchial lymph nodes was noted. Peribronchial lymphoid aggregates were present in one fetus at 145 days gestation, 24 days after inoculation. AdSV-20 was isolated with greatest frequency from lung, followed in decreasing prevalence, from tonsil, amniotic fluid, kidney, liver, spleen, and placenta of nonimmune fetuses. Seven fetuses of immune dams were inoculated with AdSV-20 at various ages ranging from 90 to 126 days of age. Of the two fetuses which developed pneumonia, neither contained widespread pulmonary necrosis, nor was AdSV-20 isolated from the lung. AdSV-20 was isolated from the morphologically normal lung of one immune fetus 7 days postinoculation. AdSV-20 infection of 90- to 130-day rhesus fetuses represents a model for study of the pathogenesis of fetal pneumonia and, potentially, virus-induced pulmonary hypoplasia. Both lesions appear to be based on the selective tropism of AdSV-20 for the undifferentiated epithelial cell of the fetal lung.
|Original language||English (US)|
|Number of pages||9|
|State||Published - Dec 27 1979|
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Molecular Biology
- Cell Biology