AUTHOR=Sharma Shreya , Khosla Ritu , David Paul , Rastogi Archana , Vyas Ashish , Singh Dileep , Bhardwaj Ankit , Sahney Amrish , Maiwall Rakhi , Sarin Shiv K., Trehanpati Nirupma 

TITLE=CD4+CD25+CD127low regulatory T cells play predominant anti-tumor suppressive role in hepatitis B virus associated hepatocellular carcinoma

JOURNAL=Frontiers in Immunology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2015.00049

DOI=10.3389/fimmu.2015.00049

ISSN=1664-3224

ABSTRACT=<p><bold>Background:</bold> Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide and hepatitis B is one of the commonest causes. T regulatory cells (Tregs) are strong immunomodulators and are likely to play a major role in HCC development. HBV infection is reported to induce expansion of Tregs. We investigated the CD4+CD25+CD127<sup>−ve</sup>FoxP3+ Tregs in HBV-related HCC as compared to non-HBV-HCC.</p><p><bold>Patients and Methods:</bold> Whole blood immunophenotyping was analyzed by multicolor flow cytometry in patients with HBV-related HCC (HBV-HCC, <italic>n</italic> = 17), non-HBV-HCC (<italic>n</italic> = 22; NASH = 16, alcohol-related = 6), and chronic hepatitis B infection (CHBV; <italic>n</italic> = 10). Tregs functionality was checked by <italic>in vitro</italic> suppression assays using CD4+ CD25+ CD127<sup>low</sup> Tregs. Levels of serum alpha-fetoprotein (AFP), expression of FoxP3, IL-10, PD1, TGF-β, and Notch in Tregs, and liver explants were analyzed by flow cytometry, immunohistochemistry, and quantitative RT-PCR.</p><p><bold>Results:</bold> CD4+CD25+<sup>hi</sup> and Foxp3 expression in CD4+CD25+<sup>hi</sup>CD127<sup>low</sup> was significantly increased (<italic>P</italic> = 0.04, <italic>P</italic> = 0.007) in HBVHCC compared to non-HBVHCC and CHBV patients. HBVHCC also showed high IL-10 and TGF-β secreting CD4 + CD25 + <sup>hi</sup>Tregs. The PD1 expression in CD4 + CD25+<sup>hi</sup> was significantly decreased in the HBVHCC than non-HBVHCC. In HBVHCC, AFP levels were significantly high (median 941, range 2–727940) than non-HBVHCC (median 13.5, range 2–18,900). In HBVHCC, patients with high AFP (range; 3982–727940 ng/ml) showed positive correlation with Foxp3 expression in CD4+CD25+<sup>hi</sup> CD127<sup>low</sup> (<italic>r</italic> = 0.857, <italic>P</italic> = 0.014). Reduced PD1 expression in HBVHCC also had negative correlation with FOXP3 in CD4+CD25+<sup>hi</sup> CD127<sup>low</sup> (<italic>r</italic> = −0.78, <italic>P</italic> = 0.04). However, AFP levels in non-HBVHCC showed negative correlation with (<italic>R</italic> = −0.67, <italic>P</italic> = 0.005) with CD4+CD25+<sup>hi</sup> Tregs.</p><p><bold>Conclusion:</bold> Our results demonstrate that CD4+ CD25+<sup>hi</sup> Tregs from HBVHCC patients have decreased expression of PD1, resulting in higher IL-10 and TGF-β secretion. Increased suppressive ability of Tregs in HBV-related HCC confers increased anti-tumor suppressive response than in non-HBV-HCC. Modulation of Tregs and PD1 may serve as useful therapeutic targets.</p>