EXPRESSION OF EARLY AND LATE ADENOVIRAL PROTEINS IN FATAL ADENOVIRUS BRONCHOPNEUMONIA

The localization and distribution of three adenoviral proteins, hexon, E1A, and 55-kDa E1B in 16 cases of fatal adenovirus bronchopneumonia in infants and children, are described. The proteins were immunohistoc hemically demonstrated in paraffin sections using monoclonal antibodie s followed by the avidin-biotin-peroxidase method. The hexon antigen w as present in inclusion-bearing bronchial, bronchiolar, and alveolar c ells, mainly in the so-called rosette cells, as well as in necrotic de bris in necrotizing areas. E1A antigen was also recognized in cells wi th nuclear inclusions where the reaction decorated the inclusion, nucl ear chromatin, and cytoplasm but distributed mainly in alveolar cells and to a lesser extent in bronchial and bronchiolar cells. The 55-kDa E1B protein was extensively present in ''activated,'' reactive-appeari ng nuclei of bronchial, bronchiolar, and alveolar epithelial cells and in the cytoplasm of rare cells having nuclear inclusions. These activ ated nuclei did not stain for the other two antigens. ''Smudge '' cell s reacted poorly or not at all with any of the antibodies. The reactiv ity found produced a sort of complementary pattern between the hexon-p ositive, inclusion-containing cells and the 55-kDa E1B-positive, inclu sion-noncontaining cells. The relationships of present findings and vi rologic data are discussed.