title: Analysis of the immune response of human dendritic cells to Mycobacterium tuberculosis by quantitative proteomics.
abstract: BACKGROUND
  The cellular immune response for Mycobacterium tuberculosis (M. tuberculosis) infection remained incompletely understood. To uncover membrane proteins involved in this infection mechanism, an integrated approach consisting of an organic solvent-assisted membrane protein digestion, stable-isotope dimethyl labeling and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used to comparatively profile the membrane protein expression of human dendritic cells upon heat-killed M. tuberculosis (HKTB) treatment.
  
  
  RESULTS
  Organic solvent-assisted trypsin digestion coupled with stable-isotope labeling and LC-MS/MS analysis was applied to quantitatively analyze the membrane protein expression of THP-1 derived dendritic cells. We evaluated proteins that were upregulated in response to HKTB treatment, and applied STRING website database to analyze the correlations between these proteins. Of the investigated proteins, aminopeptidase N (CD13) was found to be largely expressed after HKTB treatment. By using confocal microscopy and flow cytometry, we found that membranous CD13 expression was upregulated and was capable of binding to live mycobacteria. Treatment dendritic cell with anti-CD13 antibody during M. tuberculosis infection enhanced the ability of T cell activation.
  
  
  CONCLUSIONS
  Via proteomics data and STRING analysis, we demonstrated that the highly-expressed CD13 is also associated with proteins involved in the antigen presenting process, especially with CD1 proteins. Increasing expression of CD13 on dendritic cells while M. tuberculosis infection and enhancement of T cell activation after CD13 treated with anti-CD13 antibody indicates CD13 positively involved in the pathogenesis of M. tuberculosis.
authors.affiliation: Division of Chest Medicine, Department of Internal Medicine, Mackay Memorial Hospital, 92, Sec 2, Chungshan North Road, Taipei, Taiwan.
authors.forename: Chiu-Ping
authors.initials: CP
authors.lastname: Kuo
authors.affiliation: Department of Emergency Medicine, Mackay Memorial Hospital, Taipei, Taiwan.|Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan.
authors.forename: Kuo-Song
authors.initials: KS
authors.lastname: Chang
authors.affiliation: Graduate Institute of Biotechnology, National Pingtung University of Science and Technology, Pingtung, 91201 Taiwan.
authors.forename: Jue-Liang
authors.initials: JL
authors.lastname: Hsu
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: I-Fang
authors.initials: IF
authors.lastname: Tsai
authors.affiliation: Biology Department, Case Western Reserve University, Cleveland, OH USA.
authors.forename: Andrew Boyd
authors.initials: AB
authors.lastname: Lin
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Tsai-Yin
authors.initials: TY
authors.lastname: Wei
authors.affiliation: Division of Chest Medicine, Department of Internal Medicine, Mackay Memorial Hospital, 92, Sec 2, Chungshan North Road, Taipei, Taiwan.|Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan.
authors.forename: Chien-Liang
authors.initials: CL
authors.lastname: Wu
authors.affiliation: Division of Chest Medicine, Department of Internal Medicine, Mackay Memorial Hospital, 92, Sec 2, Chungshan North Road, Taipei, Taiwan.|Department of Medicine, Mackay Medical College, New Taipei City, Taiwan.
authors.forename: Yen-Ta
authors.identifier: 0000-0002-9798-8355
authors.initials: YT
authors.lastname: Lu
keywords: Antigen presentation; CD13; M. tuberculosis; Membrane proteomics