Synchrony of high endothelial venules and lymphatic vessels revealed by immunization

S Liao, NH Ruddle - The Journal of Immunology, 2006 - journals.aai.org
The Journal of Immunology, 2006journals.aai.org
The mature phenotype of peripheral lymph node (LN) high endothelial venules (HEVs),
defined as MAdCAM-1 low PNAd high LTβR high HEC-6ST high, is dependent on signaling
through the lymphotoxin-β receptor (LTβR). Plasticity of PLN HEVs during immunization with
oxazolone was apparent as a reversion to an immature phenotype (MAdCAM-1 high PNAd
low LTβR low HEC-6ST low) followed by recovery to the mature phenotype. The recovery
was dependent on B cells and was inhibited by LTβR-Ig treatment. Concurrent with HEV …
Abstract
The mature phenotype of peripheral lymph node (LN) high endothelial venules (HEVs), defined as MAdCAM-1 low PNAd high LTβR high HEC-6ST high, is dependent on signaling through the lymphotoxin-β receptor (LTβR). Plasticity of PLN HEVs during immunization with oxazolone was apparent as a reversion to an immature phenotype (MAdCAM-1 high PNAd low LTβR low HEC-6ST low) followed by recovery to the mature phenotype. The recovery was dependent on B cells and was inhibited by LTβR-Ig treatment. Concurrent with HEV reversion, at day 4 following oxazolone or OVA immunization, reduced accumulation of Evans blue dye and newly activated DCs in the draining LNs revealed a temporary afferent lymphatic vessel (LV) functional insufficiency. T cell priming to a second Ag was temporarily inhibited. At day 7, lymphangiogenesis peaked in both the skin and draining LN, and afferent LV function was restored at the same time as HEV phenotype recovery. This process was delayed in the absence of B cells. LV and HEV both express the LTβR. During lymphangiogenesis in the draining LN, HEV, and LV were directly apposed; some vessels appeared to express both PNAd and LYVE-1. Pretreatment with LTβR-Ig drastically reduced the number of PNAd+ LYVE-1+ vessels, suggesting a reduction in LV and HEV cross-talk. The concordance in time and function and the close physical contact between LVs and HEVs in the remodeling process after immunization indicate that the two vascular systems are in synchrony and engage in cross-talk through B cells and LTβR.
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