CD14+ regulatory dendritic cells in patients with hepatocellular carcinoma and cirrhosis
Authors: Shiroh Tanoue, David E. Kaplan
Journal: Hepatology (2015)

This work was supported by the National Institutes of Health (R01 CA 166111; to D.E.K.). Potential conflict of interest: Nothing to report. Author names in bold designate shared co‐first authorship. To the Editor: We read with great interest the article by Han et al.,1 who described a population of peripheral CD11bhighCD11chigh dendritic cells (DCs), termed CD14+ DCs, that appeared to be specifically found in hepatocellular carcinoma (HCC) patients, but not from healthy donors. CD11b+CD11c+ DCs have been shown to induce regulatory T cells and secrete interleukin (IL)‐10 and transforming growth factor beta in autoimmune disease models.2 BDCA1+ myeloid DCs with a similar surface phenotype may have immunoregulatory functions in chronic viral hepatitis (CVH).4 Cirrhosis has an important impact on CD14+ monocyte frequency and phenotype,5 but non‐HCC‐bearing patients with cirrhosis were not included as a control group in this study. To confirm the study's findings and determine any association of cirrhosis with the described phenotype, we recruited age‐matched patients with cirrhosis (CIR; n = 20), HCC patients (n = 10), and healthy donors (HD; n = 7) and assessed the distribution of CD14+ DCs (CD11bhighCD11chighHLA‐DR+CD14+ cells) by flow cytometry. Contrasting with Han et al., we could not reproduce the observed results regarding the increased frequency of this novel CD14+ DC subset in liver cancer patients, noncancer patients with cirrhosis, or HDs (Fig. 1A). Furthermore, we found no clear differences of phagocytic ability among monocytes, CD14+DCs, and monocyte‐derived dendritic cells (MoDCs) derived from HDs and patients with cirrhosis (Fig. 1B). Whereas we did identify that cirrhotic monocytes secreted higher levels of IL‐10 than HDs, CD14+ DCs and MoDC were no different in this respect between CIR and HD (Fig. 1C).Figure 1: (A) Frequency of CD14+ CD11bhighCD11chighHLA‐DR+CD14+ (CD14+ DC) cells in peripheral blood mononuclear cells of patients with cirrhosis, liver cancer (HCC), and HDs. Representative dot plots and comparison by Kruskal‐Wallis' testing shown. (B) FITC‐conjugated dextran uptake of monocytes (CD14+), MoDCs, and CD14+ DCs in patients with cirrhosis and HDs. MoDCs were generated by culturing CD14+ monocytes with granulocyte macrophage colony‐stimulating factor 50 ng/mL and IL‐4 1,000 U/mL for 4 days. Purified monocytes, CD14+ DCs, and MoDCs were incubated at 37°C for 4 hours with FITC‐dextran (dark line). Cells incubated with FITC‐dextran at 4°C (light line) and without FITC‐dextran at 37°C (gray shaded). (C) Intracellular IL‐10 expression of monocytes, CD14+ DCs, and MoDCs after stimulation with or without LPS. Abbreviations: FITC, fluorescein isothiocyanate; LPS, lipopolysaccharide; MFI, mean fluorescence intensity.One possible cause for the discrepancy between our findings and those of Han et al. could be the effect of aging. Whereas we recruited age‐matched HDs, the HDs recruited by Han et al. were significantly younger than their HCC patients (median, 27 vs. 49 years old). Age‐related increases in the prevalence of circulating CD11b+CD11c+ DCs was indeed identified in a mouse model of lupus.6 On the other hand, Han et al. did include nonliver cancer controls that were age‐matched and differed in frequency of CD14+ DC from their HCC patients. Though we found no difference in CD14+ DC frequency between chronic hepatitis C‐infected and nonhepatitis C virus‐infected subjects with cirrhosis (data not shown), it is possible that chronic hepatitis B infection could also explain differences in the frequency of CD14+ DCs they observed. In summary, we were unable to reproduce the findings of Han et al. with regard to the association of CD14+CD11bhighCD11chigh DCs with HCC. We recommend further validation of this putative HCC phenotype with the appropriate control populations, specifically age‐matched non‐cancer‐bearing patients with cirrhosis, CVH patients without cirrhosis, and age‐matched HDs.