Psoriasis: a T-cell-mediated autoimmune disease induced by streptococcal superantigens?
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.
Valdimarsson
H
H
Dept of Immunology, National University Hospital, Reykjavík, Iceland.
Baker
B S
BS
Jónsdóttir
I
I
Powles
A
A
Fry
L
L
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*
D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens