title: Functionally aberrant dendritic cell subsets and expression of DC-SIGN differentiate acute from chronic HBV infection.
abstract: BACKGROUND
  Dendritic cells (DCs) promote pathogen recognition, uptake and presentation of antigen through DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN) and toll-like receptors (TLRs).
  
  
  OBJECTIVE
  We aimed to study temporal changes in DCs, TLRs and DC-SIGN during acute viral hepatitis B (AVHB) infection and compare them to chronic (CHB) and to investigate the earliest time point of activated pathogen recognition receptors in hepatitis B viral infection.
  
  
  METHODS
  We measured the frequencies of circulating myeloid (mDC) and plasmacytoid (pDC) dendritic cells and IFN-α production along with the expression of DC-SIGN and Toll Like Receptors (TLR's) in HBV patients at different time points. Also investigated in healthy volunteers, the dynamic changes in TLRs expression after receiving hepatitis B vaccine.
  
  
  RESULTS
  On follow-up of AVHB patients, we found the mDC population was significantly higher at week 4 and 6 (p < 0.02, 0.01), whereas the pDC population was unchanged at week 6 compared with week 0. Whereas frequencies of mDCs and pDCs were found to be elevated in AVHB and CHB patients than HC (p < 0.00 and 0.01, respectively) but was comparable among AVHB vs CHB. The DCs in CHB patients were functionally impaired with significantly low IFN-α production and low DCSIGN expression (p < 0.04 and 0.00, respectively). Even after stimulation by TLR agonists, no change was found in IFN-α production in CHB patients. MyD88 and IL-6, IFN-α mRNA levels were also found down-regulated. Interestingly, on follow-up after HBV vaccine, TLRs expression was found high at day 3 after vaccination.
  
  
  CONCLUSIONS
  The initial events of immune activation might be responsible for modulating immune response. These novel observations would pave the way for the development of antiviral strategies for chronic HBV infection.
authors.affiliation: Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Sukriti
authors.initials: S
authors.lastname: Sukriti
authors.affiliation: Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Nirupma
authors.initials: N
authors.lastname: Trehanpati
authors.affiliation: Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Manoj
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Chandana
authors.initials: C
authors.lastname: Pande
authors.affiliation: Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, Delhi, India.
authors.forename: Syed S
authors.initials: SS
authors.lastname: Hissar
authors.affiliation: Department of Molecular and Cellular Medicine, Institute of Liver and Biliary Sciences, Delhi, India. sksarin@ilbs.in.|Department of Hepatology, Institute of Liver and Biliary Sciences, Delhi, India. sksarin@ilbs.in.
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Sarin
mesh_terms: D000328:Adult; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003713:Dendritic Cells / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D006509:Hepatitis B / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000276:immunology*; D006801:Humans; D016898:Interferon-alpha / Q000097:blood / Q000235:genetics; D015850:Interleukin-6 / Q000235:genetics; D037181:Lectins, C-Type / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics; D011956:Receptors, Cell Surface / Q000378:metabolism*; D051193:Toll-Like Receptors; D055815:Young Adult; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015815:Cell Adhesion Molecules; D017325:Hepatitis B Vaccines; D016898:Interferon-alpha; D015850:Interleukin-6; D037181:Lectins, C-Type; D053594:Myeloid Differentiation Factor 88; D011956:Receptors, Cell Surface; D051193:Toll-Like Receptors; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin; C508600:IL6 protein, human; C507779:MYD88 protein, human
keywords: DC-SIGN; Dendritic cell subsets; Hepatitis B; Toll-like receptors