| First Author | Aichberger KJ | Year | 2005 |
| Journal | J Immunol | Volume | 175 |
| Issue | 2 | Pages | 1286-94 |
| PubMed ID | 16002733 | Mgi Jnum | J:100757 |
| Mgi Id | MGI:3589505 | Doi | 10.4049/jimmunol.175.2.1286 |
| Citation | Aichberger KJ, et al. (2005) Hom s 4, an IgE-reactive autoantigen belonging to a new subfamily of calcium-binding proteins, can induce Th cell type 1-mediated autoreactivity. J Immunol 175(2):1286-94 |
| abstractText | Skin inflammation in atopic dermatitis starts with Th2 and IgE-mediated responses against exogenous allergens and, for unknown reasons, resembles features of a Th1-driven reaction in the chronic stages. We report the characterization of a human protein, Hom s 4, recognized by IgE autoantibodies from atopic dermatitis patients. The complete Hom s 4 cDNA codes for a 54-kDa basic protein containing two typical calcium-binding domains separated by an unusually long alpha-helical domain. Therefore, Hom s 4 and homologous proteins found by sequence comparison in mice, fruit flies, and nematodes constitute a novel subfamily of calcium-binding proteins. Using Hom s 4-specific Abs, it is demonstrated that the protein is strongly expressed within epidermal keratinocytes and dermal endothelial cells. Purified Hom s 4 showed IgE cross-reactivity with exogenous calcium-binding allergens from plants and fish but, in contrast to the exogenous allergens, induced only weak histamine release from patient basophils. However, the analysis of Hom s 4-specific cytokine and humoral immune responses indicated that Hom s 4 strongly induces Th1 responses which are accompanied by the release of IFN-gamma, a cytokine implicated in epithelial cell damage. Hom s 4-induced IFN-gamma production was found in normal individuals, in patients with chronic inflammatory skin diseases and in Th2-prone atopic persons, suggesting that Hom s 4 represents a protein with an intrinsic property to induce Th1-mediated autoreactivity. It may thus contribute to chronic skin inflammation in atopic as well as in nonatopic persons. |
