title: Quantitative whole-cell MALDI-TOF MS fingerprints distinguishes human monocyte sub-populations activated by distinct microbial ligands.
abstract: BACKGROUND
  Conventionally, human monocyte sub-populations are classified according to surface marker expression into classical (CD14(++)CD16(-)), intermediate (CD14(++)CD16(+)) and non-classical (CD14(+)CD16(++)) lineages. The involvement of non-classical monocytes, also referred to as proinflammatory monocytes, in the pathophysiology of diseases including diabetes mellitus, atherosclerosis or Alzheimer's disease is well recognized. The development of novel high-throughput methods to capture functional states within the different monocyte lineages at the whole cell proteomic level will enable real time monitoring of disease states.
  
  
  RESULTS
  We isolated and characterized (pan-) monocytes, mostly composed of classical CD16(-) monocytes, versus autologous CD16(+) subpopulations from the blood of healthy human donors (n = 8) and compared their inflammatory properties in response to lipopolysaccharides and M.tuberculosis antigens by multiplex cytokine profiling. Following resting and in vitro antigenic stimulation, cells were recovered and subjected to whole-cell mass spectrometry analysis. This approach identified the specific presence/absence of m/z peaks and therefore potential biomarkers that can discriminate pan-monocytes from their CD16 counterparts. Furthermore, we found that semi-quantitative data analysis could capture the subtle proteome changes occurring upon microbial stimulation that differentiate resting, from lipopolysaccharides or M. tuberculosis stimulated monocytic samples.
  
  
  CONCLUSIONS
  Whole-cell mass spectrometry fingerprinting could efficiently distinguish monocytic sub-populations that arose from a same hematopoietic lineage. We also demonstrate for the first time that mass spectrometry signatures can monitor semi-quantitatively specific activation status in response to exogenous stimulation. As such, this approach stands as a fast and efficient method for the applied immunology field to assess the reactivity of potentially any immune cell types that may sustain health or promote related inflammatory diseases.
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss TPH, Basel, Switzerland. damien.portevin@unibas.ch.|University of Basel, 4002, Basel, Switzerland. damien.portevin@unibas.ch.
authors.forename: Damien
authors.initials: D
authors.lastname: Portevin
authors.affiliation: Mabritec AG, Riehen, Switzerland. valentin.pflueger@mabritec.com.
authors.forename: Valentin
authors.initials: V
authors.lastname: Pflüger
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss TPH, Basel, Switzerland. patriciaotieno@rocketmail.com.|University of Basel, 4002, Basel, Switzerland. patriciaotieno@rocketmail.com.
authors.forename: Patricia
authors.initials: P
authors.lastname: Otieno
authors.affiliation: Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich, Switzerland. rene.brunisholz@fgcz.ethz.ch.
authors.forename: René
authors.initials: R
authors.lastname: Brunisholz
authors.affiliation: Mabritec AG, Riehen, Switzerland. Guido.Vogel@mabritec.com.
authors.forename: Guido
authors.initials: G
authors.lastname: Vogel
authors.affiliation: Department of Medical Parasitology and Infection Biology, Swiss TPH, Basel, Switzerland. Claudia.Daubenberge@unibas.ch.|University of Basel, 4002, Basel, Switzerland. Claudia.Daubenberge@unibas.ch.
authors.forename: Claudia
authors.initials: C
authors.lastname: Daubenberger
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology; D018929:Cell Culture Techniques; D002469:Cell Separation / Q000379:methods*; D002478:Cells, Cultured; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology; D009000:Monocytes / Q000737:chemistry / Q000145:classification* / Q000166:cytology / Q000276:immunology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000942:Antigens, Bacterial; D008070:Lipopolysaccharides