Role of superallergens in allergic disorders.
A significant percentage of allergic diseases (e.g. certain cases of intrinsic asthma, chronic idiopathic urticaria, and atopic dermatitis) cannot be explained by the classical mechanisms of IgE/allergen-mediated activation of basophils and mast cells. We found that protein Fv, an endogenous protein synthesized in the human liver and increased during viral hepatitis, act as a superallergen by binding to IgE of the VH3 family and activating human basophils and mast cells. Similarly, envelope gp120 of HIV-1 and protein A of Staphylococcus aureus are viral and bacterial superallergens, respectively, because they interact with IgE VH3+. Protein L binds to the V domain of he kappa light chains of IgE. Our results demonstrate that endogenous, viral and bacterial products activate primary effector cells of allergic disorders to release proinflammatory mediators and cytokines thereby acting as immunoglobulin superantigens (superallergens).
Marone
Gianni
G
Department of Clinical Immunology and Allergy, Center for Basic and Clinical Immunology Research (CISI), University of Naples Federico II, School of Medicine, Naples, Italy.
Rossi
Francesca W
FW
Detoraki
Aikaterini
A
Granata
Francescopaolo
F
Marone
Giancarlo
G
Genovese
Arturo
A
Spadaro
Giuseppe
G
D001426:Bacterial Proteins / Q000276:immunology*; D001491:Basophils / Q000502:physiology; D004268:DNA-Binding Proteins / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D006801:Humans; D006967:Hypersensitivity / Q000209:etiology*; D007073:Immunoglobulin E / Q000378:metabolism; D007143:Immunoglobulin Heavy Chains / Q000378:metabolism; D007135:Immunoglobulin Variable Region / Q000378:metabolism; D008222:Lymphokines / Q000276:immunology*; D008407:Mast Cells / Q000502:physiology; D017455:Receptors, IgE / Q000502:physiology; D012795:Sialoglycoproteins / Q000276:immunology*; D013205:Staphylococcal Protein A / Q000276:immunology*; D018089:Superantigens / Q000276:immunology*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C089422:Fv protein, human; D015699:HIV Envelope Protein gp120; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; C116593:L-protein, Peptococcus magnus; D008222:Lymphokines; D017455:Receptors, IgE; D012795:Sialoglycoproteins; D013205:Staphylococcal Protein A; D018089:Superantigens; D007073:Immunoglobulin E