title: Psoriasis: a T-cell-mediated autoimmune disease induced by streptococcal superantigens?
abstract: Psoriasis is a T-cell-mediated disease that can be triggered by infection with group A beta-haemolytic streptococci. It is proposed that psoriatic skin lesions are initiated by exotoxin-activated T cells, and persist because of specific T cells that react both with streptococcal M protein and a skin determinant, possibly a variant of keratin. As discussed here by Helgi Valdimarsson and colleagues, cytokines released by the superantigen (SAg)-stimulated T cells could induce or enhance the expression of the crossreactive autoantigen, leading to the rescue and activation of autoreactive T cells. In this way, the SAg-determined T-cell receptor V beta phenotype would be maintained by T cells in psoriatic lesions.
authors.affiliation: Dept of Immunology, National University Hospital, Reykjavík, Iceland.
authors.forename: H
authors.initials: H
authors.lastname: Valdimarsson
authors.forename: B S
authors.initials: BS
authors.lastname: Baker
authors.forename: I
authors.initials: I
authors.lastname: Jónsdóttir
authors.forename: A
authors.initials: A
authors.lastname: Powles
authors.forename: L
authors.initials: L
authors.lastname: Fry
mesh_terms: D001327:Autoimmune Diseases / Q000276:immunology*; D006801:Humans; D015603:Keratinocytes / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D011565:Psoriasis / Q000276:immunology*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000276:immunology; D013290:Streptococcal Infections / Q000276:immunology*; D013292:Streptococcus agalactiae / Q000276:immunology*; D018089:Superantigens / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens