B cell derived IL-10 does not promote viral chronicity and T cell exhaustion.

<p><i>Il-10</i>^−/−, <i>Il-10</i>^fl/flx<i>CD19-Cre</i>⁺, <i>Il-10</i>^fl/flx<i>CD19-Cre</i>⁻ and C57BL/6 mice were infected with Clone 13. Virus titers were determined in (A) spleen, (B) kidney, (C) liver and (D) lung on day 10 or day 12 post infection. (A–D) Each symbol represents one individual mouse; the solid lines represent the geometric means, the dashed line the detection limit. Statistical significance was determined with the Mann-Whitney test. (E and H) TNF-α production by CD8⁺ T cells in lung mononuclear cells was determined after 5 hours stimulation with the peptide gp33. TNF-α secretion by CD4⁺ T cells in (F and I) lung mononuclear cells and (G and J) splenocytes was determined after 5 hours stimulation with the peptide p13. Mean and standard deviation of the (E–G) percentages and (H–J) total numbers are shown. A summary of all mice from three independent experiments with 4–5 mice per group is depicted. Statistical significance was determined with unpaired 2-tailed Student's t test. n.s.: not significant; * p<0.05; ** p<0.01; *** p<0.001; *** p<0.0001.