Reovirus infection in adult mice: the virus hemagglutinin determines the site of intestinal disease.

Reovirus type 1, strain Lang, and type 3, strain Dearing, induced site-specific intestinal lesions in the adult mouse after intravenous inoculation. Reovirus type 1 caused inflammation and epithelial changes such as loss of nuclear polarity, villus blunting and crypt hyperplasia restricted to the ileum. In contrast, reovirus type 3 induced duodenitis, jejunitis, and ulcerative colitis. In the duodenum and jejunum, the epithelial cells appeared normal, but hemorrhage and inflammation in the lamina propria was present. In the colon, superficial ulceration, crypt abscesses, and intraluminal hemorrhage was observed. Segregation analysis using reassortant clones derived from reoviruses 1 and 3, suggested the viral hemagglutinin, encoded by genome segment S1, to be the major viral determinant of site specific intestinal disease following intravenous inoculation.