title: Stronger proliferative response to membrane versus cell-wall Streptococcal proteins by peripheral blood T cells in chronic plaque psoriasis.
abstract: Proliferative responses of peripheral blood mononuclear cells (PBMC) to group A streptococcal (GAS) antigens have been studied in 24 patients with psoriasis and 15 disease controls. Extracts of cell wall (including M protein) from types M4 and M12 GAS, recombinant M6 protein, and both cell-wall and cell-membrane extracts from type M6 (M6+) GAS and its corresponding M gene deletion mutant (M6-) were tested. PBMC from psoriatic patients proliferated more strongly to cell-wall extracts from M12 versus M4 (P = 0.0348), and to M6+ versus M6- (P = 0.0019) GAS with, in most cases, moderate proliferation to recombinant M6 protein. The psoriatic response to M12 cell wall was significantly increased compared to the controls (P = 0.0032). In psoriatics, M6+ membrane extracts induced a markedly greater proliferation than those of cell wall (P = 0.0002); responses to M6+ (P = 0.0039) and M6- (P = 0.0114) membrane extracts were higher than those of the control PBMC. Both groups showed a decreased response to the M6- versus M6+ membrane extracts (P = 0.0030; P = 0.0181, respectively). This study has demonstrated that patients with psoriasis have a heightened circulating T-cell response to cell wall M protein and to non-M proteins present on the cell wall and membrane of GAS.
authors.affiliation: Department of Dermatology Faculty of Medicine, Imperial College of Science, Technology & Medicine, St Mary's Campus, London, UK. b.baker@ic.ac.uk
authors.forename: B S
authors.initials: BS
authors.lastname: Baker
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: V A
authors.initials: VA
authors.lastname: Fischetti
authors.forename: J M
authors.initials: JM
authors.lastname: Ovigne
authors.forename: W
authors.initials: W
authors.lastname: Porter
authors.forename: A
authors.initials: A
authors.lastname: Powles
authors.forename: L
authors.initials: L
authors.lastname: Fry
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017951:Antigen Presentation; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology; D016022:Case-Control Studies; D002455:Cell Division; D002473:Cell Wall / Q000276:immunology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008213:Lymphocyte Activation; D008297:Male; D008565:Membrane Proteins / Q000276:immunology; D008875:Middle Aged; D011565:Psoriasis / Q000276:immunology*; D013297:Streptococcus pyogenes / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D008565:Membrane Proteins; C014689:streptococcal M protein