Localization of canine adenovirus capsid antigens in a MDCK cell line by immunoferritin and immunofluorescent techniques

The appearance and development of infectious canine laryngotracheitis adenovirus capsid antigens and their relationship to the viral induced inclusions in a canine cell line was determined using the method of staining thin sections with ferritin-labeled antibody and compared with the fluorescent-staining technique.The adenovirus fiber was the first structural antigen to appear and was detected at 9–10 h after infection in the early initial and ring-form nuclear inclusions by both the immunoferritin and immunofluorescent methods.The hexon and penton base antigens were only detectable about 2 h after the appearance of the fiber antigen. These antigens when visualized with the fluorescent technique appeared to be diffusely scattered throughout the nucleus but the ferritin technique showed that they were associated with the newly formed virus particles.The later appearing light-staining nuclear inclusions examined by ferritin staining were found to contain hexon, penton base, and fiber antigens. The dark-staining inclusion which also appears later in infection was found to contain only the hexon antigen.