title: Development of an Evaluation Device for Phagocytic Activity of New Phagocytes Using Simple and pH-sensitive Particles that Do Not Require Pre-treatment.
abstract: OBJECTIVE
  Phagocytic activity is affected by a number of different stress and age-dependent factors. An easy measurement of phagocytic activity is thought to allow an indicator of an individual's health. In this study, we investigated conditions of measurement to easily evaluate the activity of phagocytosis of phagocytic cells (macrophages and neutrophils) using an easy-to-use prototype, which was improved from the device by Hamamatsu Photonics K.K., to detect neutrophil activity using subtle fluorescence.
  
  
  METHODS
  pH-sensitive fluorescent particles (pHrodo-Green E. coli Bio particles, GE particles) were added to mouse-derived macrophage cell lines (J774.1) and then incubated for 2 h at 37°C. For negative control, the phagocytosis inhibitor cytochalasin D (CyD), was added prior to culture. Next, fluorescence intensity was measured by the Prototype to evaluate the phagocytic activity of macrophages and neutrophils. Phagocytosis was also confirmed by flow cytometry.
  
  
  RESULTS
  The Prototype detected a steady fluorescence increase in 5 sec in J774.1 after phagocytosis, using GE particles as a negative control in the presence of CyD. Furthermore, detection was possible at 10(4) cells/test, a concentration where the flow cytometer had difficulty for detection.
  
  
  CONCLUSIONS
  The Prototype enables measurement of the phagocytic activity within a short period of time, even with a small sample amount, thus establishing the basic conditions of measurements of phagocytosis.
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan zhang@shizenmeneki.org.
authors.forename: Ran
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Faculty of Medicine, Kagawa University, Kagawa, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Kimiko
authors.initials: K
authors.lastname: Kazumura
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuchiya
authors.affiliation: Electron Tube Division, Hamamatsu Photonics K.K., Hamamatsu, Japan.
authors.forename: Naokazu
authors.initials: N
authors.lastname: Morishita
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inagawa
authors.affiliation: Control of Innate Immunity, Technology Research Association, Kagawa, Japan Faculty of Medicine, Kagawa University, Kagawa, Japan Niigata University of Pharmacy and Applied Life Sciences, Niigata, Japan.
authors.forename: Gen-Ichiro
authors.initials: G
authors.lastname: Soma
mesh_terms: D006801:Humans; D006863:Hydrogen-Ion Concentration; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation; D016215:Macrophage-Activating Factors / Q000494:pharmacology* / Q000502:physiology; D008264:Macrophages / Q000187:drug effects / Q000502:physiology*; D010587:Phagocytosis; D020298:U937 Cells
chemical_list: D008070:Lipopolysaccharides; D016215:Macrophage-Activating Factors
keywords: Macrophages; pH-sensitive fluorescent particle; phagocytosis