Virus-associated innate immune activation does not alter lymphocyte numbers in the intestinal lamina propria. Mice were treated with poly(I:C) as in Figure 1. (A) Absolute lymphocyte numbers in the intestinal lamina propria were determined by flow cytometry. Each data point represents 1 individual mouse, and the mean of n = 5 poly(I:C)-stimulated and n = 3 untreated mice per group is depicted as a bar. (B) Distribution of B220⁺ B cells (red) in the intestinal lamina propria was analyzed by immunohistochemistry. (C) Serum levels of IgA and IgG were determined by enzyme-linked immunosorbent assay. Each data point represents 1 individual mouse, and the mean of n = 10 mice per group is depicted as a bar. All data are representative of at least 2 independent experiments.