A PATHWAY FOR ENTRY OF REOVIRUSES INTO THE HOST THROUGH M-CELLS OF THE RESPIRATORY-TRACT

Many microorganisms gain access to the systemic circulation after ente ring the respiratory tract. The precise pathways used to cross the muc osal barriers of the lungs have not been clearly described. We have us ed the mammalian reoviruses in order to determine the pathway that a s ystemic virus uses to penetrate the mucosal barrier and enter the syst emic circulation after entering the airways of the lungs. Reoviruses e nter through pulmonary M cells, which overlie bronchus-associated lymp hoid tissue, and subsequently spread to regional lymph nodes. Thus, th e pathway through M cells represents a strategy by which viruses and p robably other microorganisms can penetrate the mucosal surface of the respiratory tract and thereby enter the systemic circulation.