title: Novel identification and characterisation of Transient receptor potential melastatin 3 ion channels on Natural Killer cells and B lymphocytes: effects on cell signalling in Chronic fatigue syndrome/Myalgic encephalomyelitis patients.
abstract: BACKGROUND
  Transient receptor potential melastatin 3 (TRPM3) cation channels are ubiquitously expressed by multiple cells and have an important regulatory role in calcium-dependent cell signalling to help maintain cellular homeostasis. TRPM3 protein expression has yet to be determined on Natural Killer (NK) cells and B lymphocytes. Multiple single nucleotide polymorphisms have been reported in TRPM3 genes from isolated peripheral blood mononuclear cells, NK and B cells in Chronic fatigue syndrome/Myalgic encephalomyelitis (CFS/ME) patients and have been proposed to correlate with illness presentation. The object of the study was to assess TRPM3 surface expression on NK and B lymphocytes from healthy controls, followed by a comparative investigation examining TRPM3 surface expression, and cytoplasmic and mitochondrial calcium influx in CD19(+) B cells, CD56(bright) and CD56(dim) cell populations from CFS/ME patients.
  
  
  RESULTS
  TRPM3 cell surface expression was identified for NK and B lymphocytes in healthy controls (CD56(bright) TRPM3 35.72 % ± 7.37; CD56(dim) 5.74 % ± 2.00; B lymphocytes 2.05 % ± 0.19, respectively). There was a significant reduction of TRPM3 surface expression on CD19(+) B cells (1.56 ± 0.191) and CD56(bright) NK cells (17.37 % ± 5.34) in CFS/ME compared with healthy controls. Anti-CD21 and anti-IgM conjugated biotin was cross-linked with streptavidin,and subsequently treatment with thapsigargin. This showed a significant reduction in cytoplasmic calcium ion concentration in CD19(+) B lymphocytes. CD56(bright) NK cells also had a significant decrease in cytoplasmic calcium in the presence of 2-APB and thapsigargin in CFS/ME patients.
  
  
  CONCLUSIONS
  The results from this preliminary investigation identify, for the first time, TRPM3 surface expression on both NK and B lymphocytes in healthy controls. We also report for the first time, significant reduction in TRPM3 cell surface expression in NK and B lymphocytes, as well as decreased intracellular calcium within specific conditions in CFS/ME patients. This warrants further examination of these pathways to elucidate whether TRPM3 and impaired calcium mobilisation has a role in CFS/ME.
authors.affiliation: The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute, Griffith University, Parklands Drive, Southport, Mailbox 68, Gold Coast, 4222, Australia. thao.nguyen2@griffithuni.edu.au.|School of Medical Science, Griffith University, Gold Coast, Australia. thao.nguyen2@griffithuni.edu.au.
authors.forename: T
authors.initials: T
authors.lastname: Nguyen
authors.affiliation: The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute, Griffith University, Parklands Drive, Southport, Mailbox 68, Gold Coast, 4222, Australia.|School of Medical Science, Griffith University, Gold Coast, Australia.
authors.forename: D
authors.initials: D
authors.lastname: Staines
authors.affiliation: Department of Molecular Cell Biology, Laboratory of Ion Channel Research, KU Leuven University, 49 Herestraat, Leuven, B-3000, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Nilius
authors.affiliation: The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute, Griffith University, Parklands Drive, Southport, Mailbox 68, Gold Coast, 4222, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Smith
authors.affiliation: The National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute, Griffith University, Parklands Drive, Southport, Mailbox 68, Gold Coast, 4222, Australia.|School of Medical Science, Griffith University, Gold Coast, Australia.
authors.forename: S
authors.initials: S
authors.lastname: Marshall-Gradisnik
mesh_terms: D000704:Analysis of Variance; D001402:B-Lymphocytes / Q000378:metabolism*; D015220:Calcium Channels / Q000097:blood; D016022:Case-Control Studies; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000188:drug therapy; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016130:Immunophenotyping / Q000379:methods; D007694:Killer Cells, Natural / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D050053:TRPM Cation Channels / Q000378:metabolism*; D019284:Thapsigargin / Q000627:therapeutic use
chemical_list: D015220:Calcium Channels; D004791:Enzyme Inhibitors; D050053:TRPM Cation Channels; C475667:TRPM3 protein, human; D019284:Thapsigargin
keywords: Calcium signalling; Chronic fatigue syndrome; Myalgic encephalomyelitis; Transient receptor potential