title: Increased Toll-like receptor 9 expression by B cells from inflammatory bowel disease patients.
abstract: BACKGROUND
  Toll-like receptors (TLRs) are important mediators of the innate immune response. Our aim was to evaluate TLR9 expression in peripheral B cells, taken from inflammatory bowel disease (IBD) patients before and after anti-inflammatory treatment. Nineteen patients with IBD (12-crohn's disease, 7-ulcerative colitis) and 18 healthy controls were included in the study. Disease severity was assessed using the Pediatric/Adults crohn's disease activity index and the ulcerative colitis activity index as needed. Accordingly, patients were classified as mild, moderate or severe disease. Peripheral B cells isolated from IBD patients, before and after anti-inflammatory treatment, and from the control group, were cultured for 24 h with and without CpG oligodeoxynucleotides (ODN-CpG) 0.5 μM. TLR9 expression by memory B cells (CD19+CD27+) was assessed by flow cytometry.
  
  
  RESULTS
  We found that TLR9 expression by peripheral B cells was significantly higher in IBD patients than that in healthy controls (12.42 ± 9.5 MFI vs. 6.0 ± 2.6 MFI p = 0.02). The addition of ODN-CpG to B cells resulted in a significantly increase of TLR9 expression in B cells from healthy controls (6.5 ± 3.2 MFI vs. 8.8 ± 4.2 MFI p = 0.007). On the contrary, B cells from IBD patients only partly respond to the addition of ODN-CpG after anti-inflammatory treatment (6.3 ± 3.8 vs. 7.3 ± 3.7, p = 0.1). TLR9 expression was positively correlated with IBD disease severity (r = 0.681, p < 0.0001).
  
  
  CONCLUSIONS
  TLR9 expression in memory B from IBD patients is elevated and associated with disease severity.
authors.affiliation: Division of Pediatric Gastroenterology, Bnai Zion Medical Center, Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Drora
authors.initials: D
authors.lastname: Berkowitz
authors.forename: Regina
authors.initials: R
authors.lastname: Peri
authors.forename: Alexandra
authors.initials: A
authors.lastname: Lavy
authors.forename: Aharon
authors.initials: A
authors.lastname: Kessel
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D016175:B-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D051940:B7-2 Antigen / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D015212:Inflammatory Bowel Diseases / Q000175:diagnosis / Q000276:immunology* / Q000378:metabolism* / Q000628:therapy; D037181:Lectins, C-Type / Q000378:metabolism; D008297:Male; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology; D012720:Severity of Illness Index; D051217:Toll-Like Receptor 9 / Q000378:metabolism*; D055815:Young Adult; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D051940:B7-2 Antigen; D000949:Histocompatibility Antigens Class II; D037181:Lectins, C-Type; D009838:Oligodeoxyribonucleotides; D051217:Toll-Like Receptor 9; D000099192:CD69 Antigens; C408982:CPG-oligonucleotide