Bovine adenovirus type 3 pneumonia in dexamethasone-treated calves.
The effects of immunosuppression were examined in 1.5-month-old calves that were given dexamethasone (DM) before endobronchial inoculation with bovine adenovirus type 3 (BAV-3). Immunohistopathologically, severe necrotizing bronchiolitis with eosinophilic and basophilic intranuclear inclusion bodies was observed both in DM-treated 1.5-month-old infected calves and in non-DM-treated 7-day-old infected calves. These inclusion bodies were correlated with the detection of BAV-3 antigen and viral particles. The presence of inclusion bodies in the desquamated epithelial cells or of BAV-3 antigen, or both, correlated well with the isolated level of BAV-3 in bronchoalveolar lavage (BAL) fluid. Few immunoglobulin (IgG, IgM, and IgA)-containing B lymphocytes or CD8+ T lymphocytes infiltrated the pneumonic lesion in both the 7-day-old and the DM-treated 1.5-month-old infected calves. Thus, depletion of CD8+ T lymphocytes in calves might influence the clearance of BAV-3 from respiratory tissues.
Narita
M
M
National Institute of Animal Health, Shichinohe, Kamikita, Aomori 039-2586, Japan. mnarita@affrc.go.jp.
Yamada
M
M
Tsuboi
T
T
Kawashima
K
K
D000257:Adenoviridae Infections / Q000276:immunology / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000378:metabolism; D000956:Antigens, Viral / Q000378:metabolism; D001990:Bronchiolitis, Viral / Q000276:immunology / Q000473:pathology / Q000662:veterinary*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000821:virology; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology / Q000473:pathology / Q000821:virology*; D003907:Dexamethasone / Q000494:pharmacology*; D016867:Immunocompromised Host; D007150:Immunohistochemistry / Q000662:veterinary; D002479:Inclusion Bodies / Q000473:pathology / Q000648:ultrastructure / Q000821:virology; D008168:Lung / Q000473:pathology / Q000648:ultrastructure / Q000821:virology; D008297:Male; D017921:Mastadenovirus / Q000254:growth & development*; D008854:Microscopy, Electron / Q000662:veterinary; D011024:Pneumonia, Viral / Q000276:immunology / Q000473:pathology / Q000662:veterinary* / Q000821:virology
D000914:Antibodies, Viral; D000956:Antigens, Viral; D003907:Dexamethasone