Decreased Patrolling Efficiency and Decreased ConA Hepatitis Severity in CXCR6-Deficient Mice

<div><p>(A) Serum transaminase levels in <i>cxcr6^gfp/gfp</i>, <i>cxcr6^gfp/+</i>, and <i>cxcr6^+/+</i> littermates 12 h after a challenge with 20 mg/kg ConA IP. Results are pooled from two independent experiments. The horizontal line represents the upper limit for normal serum transaminase levels, as measured in unchallenged mice. Asterisk indicates a two-tailed student's <i>t</i>-test with a <i>p</i> < 0.05 in comparison with littermates.</p> <p>(B) Hematoxylin and eosin staining of paraffin-embedded liver sections from <i>cxcr6^gfp/+</i> and <i>cxcr6^gfp/gfp</i> mice sacrificed 12 h after a challenge with 20 mg/kg ConA IP.</p> <p>(C) Reduced sinusoid patrolling by NKT cells in <i>cxcr6^gfp/gfp</i> mice. By measuring the average inter-nuclei distance of hepatocytes in high-magnification images, the average sinusoidal length of a hepatocyte was determined to be 28.6 μm (data not shown). Utilizing the lymphocyte velocity data (left panel) and assuming that a CD1d-reactive T cell can contact only one hepatocyte at a time, we calculated that each CD1d-reactive T cell can visit 0.58 hepatocytes/min in the <i>cxcr6^gfp/+</i> mice, and 0.64 hepatocytes/min in the CXCR6-deficient mice. The density of GFP⁺ cells in <i>cxcr6^gfp/+</i> and <i>cxcr6^gfp/gfp</i> mice (middle panel) was calculated from the intravital videos used in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030113#pbio-0030113-g003" target="_blank">Figure 3</a> and the flow cytometry data in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030113#pbio-0030113-g002" target="_blank">Figure 2</a>. Combining the similar crawling velocities with the different steady-state densities, we show decreased rate of patrolling by GFP⁺ lymphocytes, expressed as the average time between “visitation” of any single hepatocyte (right panel).</p>