title: Surface Antigen Profiling of Helicobacter pylori-Infected and -Uninfected Gastric Cancer Cells Using Antibody Microarray.
abstract: BACKGROUND
  Comprehensive immunophenotyping cluster of differentiation (CD) antigens in gastric adenocarcinoma, specifically between Helicobacter pylori-infected and -uninfected gastric cancer patients by using DotScan(™) antibody microarray has not been conducted. Current immunophenotyping techniques include flow cytometry and immunohistochemistry are limited to the use of few antibodies for parallel examination. We used DotScan(™) antibody microarray consisting 144 CD antibodies to determine the distribution of CD antigens in gastric adenocarcinoma cells and to elucidate the effect of H. pylori infection toward CD antigen expression in gastric cancer.
  
  
  METHODS
  Mixed leukocytes population derived from gastric adenocarcinoma patients were immunophenotyped using DotScan(™) antibody microarray. AGS cells were infected with H. pylori strains and cells were captured on DotScan(™) slides.
  
  
  RESULTS
  Cluster of differentiation antigens involved in perpetuating the tolerance of immune cells to tumor cells was upregulated in gastric adenocarcinoma cells compared to normal cells. CD279 which is essential in T cells apoptosis was found to be upregulated in normal cells. Remarkably, H. pylori-infected gastric cancer patients exhibited upregulated expression of CD27 that important in maintenance of T cells. Infection of cagA+ H. pylori with AGS cells increased CD antigens expression which involved in cancer stem cell while cagA- H. pylori polarized AGS cells to express immune-regulatory CD antigens. Increased CD antigens expression in AGS cells infected with cagA+ H. pylori were also detected in H. pylori-infected gastric cancer patients.
  
  
  CONCLUSIONS
  This study suggests the tolerance of immune system toward tumor cells in gastric cancer and distinct mechanisms of immune responses exploited by different H. pylori strains.
authors.affiliation: Department of Medical Microbiology & Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Kuala Lumpur, Malaysia.
authors.forename: Asif
authors.initials: A
authors.lastname: Sukri
authors.affiliation: Department of Medical Microbiology & Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Kuala Lumpur, Malaysia. alfizah@ppukm.ukm.edu.my.
authors.forename: Alfizah
authors.initials: A
authors.lastname: Hanafiah
authors.affiliation: Department of Surgery, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Kuala Lumpur, Malaysia.
authors.forename: Nik Ritza
authors.initials: NR
authors.lastname: Kosai
authors.affiliation: Department of Surgery, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Kuala Lumpur, Malaysia.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Mohamed Taher
authors.affiliation: Department of Pathology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Kuala Lumpur, Malaysia.
authors.forename: Isa
authors.initials: I
authors.lastname: Mohamed Rose
mesh_terms: D000906:Antibodies / Q000276:immunology; D000954:Antigens, Surface / Q000032:analysis*; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000737:chemistry* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D007108:Immune Tolerance; D016130:Immunophenotyping; D007962:Leukocytes / Q000737:chemistry; D040081:Protein Array Analysis
chemical_list: D000906:Antibodies; D000954:Antigens, Surface
keywords: Antibody microarray; CD antigens; Gastric cancer; Helicobacter pylori; cagA-positive