Effect of Influenza Virus on Cilia and Epithelial Cells in the Bronchi of Mice

Abstract

A study of bronchial cilia in mice was carried out in order to obtain evidence as to how influenza viral infection of the mouse lung lowers rcsistancc to secondary pneumococcal pneumonia. Earlier work had shown that this effect is associated with the viral lesion rather than the presence of the virus per se and had suggested that viral infection damages antibacterial mechanisms of the lung (I). Particular attention was given to cilia because of the histologic evidence that influenza viral infection of the mouse causes necrosis of the bronchial epithelium (I-8). In addition, it has bccn shown that ciliary action removes foreign particles from the respiratory passages and therefore probably serves as an important mechanism of nativc resistance to bacterial infection of the respiratory tract (9-20). I When severe infection with influenza virus was induced in mice, it was found that active ciliary beat persisted in the bronchi of involved lungs and that cilia could be shown to be present in stained sections of the viral lesion. = These findings were unexpected because it was thought that this viral infection causes destruction of bronchial epithelial cells. For this reason, further experiments were done to clarify the nature of the viral lesion. The result of this investigation has revealed no evidence that actual destruction of the epithelium takes place. Instead of nuclear changes in the early viral lesion, basophilic intracytoplasmic inclusion bodies have bccn found. Evidence has also been obtained to indicate that portions of the cytoplasm of non-ciliated cells become detached and are shed into the lumen. EXPERIMENTAL METHODS AND RESULTS Wave-Like Movements of the Bronch~ ~In order to ascertain the effect of viral infection on broncial cilia, it was necessary to have a method for evaluation of ciliary action. A technique frequently

Electron Microscopy of Early Cytoplasmic Changes Due to Influenza Virus

“…Strains of Virus.--Weiss and swine strains of mouse-adapted Type A influenza virus were the same as those used in previous studies (1). A PR8 strain of mouse-adapted Type A virus was obtained from the American Type Culture Collection.…”

The Clara cell: a “Third Reich eponym”?

“…It seems that the eponym was then promoted, at least in Germany, by Erich Schiller, a pupil of Clara [47]. None of these publications or others from that period which quote Clara's paper [48,49] contain any indication of a critical stance towards Clara himself or the source of his research material. And while his former colleagues from Munich, in their statement of 1948 (see previous, and [18*]) were very critical of Clara's National Socialist engagement, they did not mention his research either.…”

Influenza Virus Receptor Specificity and Cell Tropism in Mouse and Human Airway Epithelial Cells

“…In addition to in vitro approaches, it is also critical to extend findings to an in vivo model. The mouse has historically been used for studying influenza viruses (19,57), and genetically engineered mice have been particularly valuable for understanding adaptive immune responses (49,58). However, mice differ in their susceptibilities to human virus strains (25,48).…”