Human plasmacytoid dendritic cells from patients with chronic hepatitis B induce the generation of CD4+CD25+Treg in vitro / 中华肝脏病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To compare the ability of plasmacytoid dendritic cells (pDCs) from chronic HBV patients and healthy controls to induce the the generation of CD4+CD25+Treg cells.</p><p><b>METHODS</b>The pDCs were isolated from PBMCs of 46 chronic HBV patients, 10 resolved HBV patients and 25 healthy controls by magnetic cell sorting. Purified CD4+CD45RA+ naive T cells were incubated with allogeneic pDCs from chronic HBV infected patients, resolved HBV patients or healthy controls. The cells were stimulated with HBcAg or tetanus toxin. The proportion of CD4+CD25+Treg in CD4+ T cells primed by pDCs was determined by flow cytometry, the expression of Fox p3 mRNA was detected by RT-PCR, IL-10 and TGFb1 expression was quantified using ELISA kits.</p><p><b>RESULTS</b>Compared with pDC isolated from healthy controls and the resolved HBV patients, pDC from chronic HBV patients was more effective in suppression of CD4+ T cells proliferation and interferon production when CD25-depleted PBMCs were stimulated with HBcAg, (7999.36+/-374.74 vs 11 282.56+/-1174.46; 7999.36+/-374.74 vs 12 304.58+/-1462.81, P less than 0.05 ). Depletion of CD4+CD25+ Treg from CD4+ T cells primed by pDC led to the lose of capability to suppress HBV-specific T-cell responses. When CD25- depleted PBMCs were stimulated with purified tetanus toxin, there was no significantly difference in proliferation between CD25-depleted PBMC co-cultured with pDC-primed CD4+ T cells and CD25-depleted PBMC cultured without pDC-primed CD4+ T cells. A higher percentage of CD4+CD25+ Treg was detected within the population of CD4+ T cells primed by pDC from chronic HBV patients compared with healthy controls and resolved HBV patients (5.99%+/-1.85% vs 3.04%+/-0.79%; 5.99%+/-1.85% vs 3.01%+/-1.53%, P less than 0.05). Accordingly, CD25+Treg from pDC-primed CD4+ T cells displayed a higher Fox P3 mRNA level. The IL-10 and TGFb1 could be also detectable in the supernatants of pDC-primed CD4+ T cells.</p><p><b>CONCLUSION</b>pDCs from chronic hepatitis B induce the generation of a higher proportion of CD4+CD25+ Treg compared with pDCs from healthy controls.</p>