Reovirus type I infection of small intestinal epithelium in suckling mice and its effect on M cells.
In 10-day-old mice, reovirus serotype I (reo I) selectively adheres to the apical surface of M cells and penetrates the intestinal epithelium via M cells overlying Peyer's patches before causing disseminated infection. Recently, reo I enteritis has been described in adult mice. We wished to determine if reo I enteritis also occurs in suckling mice and, if so, to determine which major epithelial cell types become infected and where the virus enters epithelial cells other than M cells. Transmission electron microscopy revealed that after oral inoculation of 10-day-old mice, peak infection of M cells preceded that of absorptive and undifferentiated crypt cells. The percentage of M cells in the dome epithelial cell population was reduced more than 4-fold between 4 and 72 hours after reo I inoculation compared with saline-inoculated mice. By 6 days after inoculation, reo I replication was no longer observed and there was a more than 2-fold increase in M cells overlying Peyer's patches domes of reo I-inoculated mice compared with saline controls. By 13 days, control and infected mice had similar percentages of M cells. When incubated with isolated intestinal epithelial sheets, reo I adhered selectively to and was endocytosed via the basal plasma membrane of absorptive cells. Thus, reo I initially penetrates the intestinal epithelium via the apical surface of M cells which become infected. Virions subsequently enter absorptive and crypt cells via their basal surfaces. During the first 3 days of enteritis, the M cell population becomes markedly depleted which may affect the permeability of the mucosal barrier to microorganisms and other antigens as well as influence the host immune response.
Bass
D M
DM
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts.
Trier
J S
JS
Dambrauskas
R
R
Wolf
J L
JL
D000818:Animals; D000833:Animals, Suckling; D002448:Cell Adhesion; D004705:Endocytosis; D004751:Enteritis / Q000382:microbiology* / Q000473:pathology; D004848:Epithelium / Q000382:microbiology / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000382:microbiology / Q000648:ultrastructure; D007583:Jejunum / Q000382:microbiology* / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D010581:Peyer's Patches / Q000382:microbiology* / Q000648:ultrastructure; D012087:Reoviridae / Q000502:physiology* / Q000648:ultrastructure; D012088:Reoviridae Infections / Q000382:microbiology* / Q000473:pathology