INDUCTION OF APOPTOSIS IN HT-29 CELLS INFECTED WITH SA-11 ROTAVIRUS

Rotavirus infection is associated both in vivo and in vitro with a ser ies of subcellular pathological alterations leading to cell lysis. it has been suggested that these modifications can play a key role in the pathogenesis of rotavirus-associated diarrheal disease. We describe t he effects of SA-11 rotavirus infection in HT-29 cells, a human entero cyte-like cell line. Cytological analyses suggested that the viral-ind uced cytopathic process, including chromatin clumping, can be referred to as apoptosis, the cell death pathway alternative to necrosis. A ti me course of the process was performed to investigate whether rotaviru s-associated cell death showed specific injury signs. HT-29-infected c ells were analyzed by scanning and transmission electron microscopy an d features of apoptosis such as blebbing of the plasma membrane, perip heral condensation of chromatin, and fragmentation of the nucleus were observed. Specific changes occurring in cell-substrate adhesion and i n some organelles relevant for viral maturation, i.e., rough endoplasm ic reticulum, were detected. These findings indicate a role for apopto sis in the rotavirus infection process and its related cytopathology, and also suggested that specific histological alterations such as dera ngement of enterocytes are associated with the pathogenesis of rotavir us-induced diarrheal disease and could be a direct consequence of vira l-triggered apoptosis. (C) 1996 Wiley-Liss, Inc.