title: HLA-C expression pattern is spatially different between psoriasis and eczema skin lesions.
abstract: Interactions between genetic and environmental factors underlie the immune dysregulation and keratinocyte abnormalities that characterize psoriasis. Among known psoriasis susceptibility loci (PSORS), PSORS1 on chromosome 6 has the strongest association to disease. Altered expression of some PSORS1 candidate genes has been reported but little is known about HLA-C expression in psoriasis. This study compared expression of major histocompatibility complex class Ia and HLA-C in psoriasis, allergic contact eczema, and normal skin. Although HLA-C was abundant in protein extracts from both eczema and psoriasis, a consistent and intriguing difference in the expression pattern was observed; strong immunoreactivity in the basal cell layer, polarized towards the basement membrane in psoriasis, whereas in eczema lesions HLA-C immunostaining was present mostly in suprabasal cells. Inflammatory cells in the dermis were strongly stained in both diseases. Normal skin epithelium showed less intense but similar HLA-C staining as eczema lesions. HLA class Ia expression overall resembled that of HLA-C in all samples. The distinct HLA-C expression patterns in psoriasis and eczema suggest a functional role in the specific psoriasis immune response and not only a general feature of inflammation.
authors.affiliation: Dermatology and Venereology Unit, Department of Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Lina
authors.initials: L
authors.lastname: Carlén
authors.forename: Kazuko
authors.initials: K
authors.lastname: Sakuraba
authors.forename: Mona
authors.initials: M
authors.lastname: Ståhle
authors.forename: Fabio
authors.initials: F
authors.lastname: Sánchez
mesh_terms: D015153:Blotting, Western; D002460:Cell Line; D003106:Colon / Q000196:embryology / Q000378:metabolism; D017449:Dermatitis, Allergic Contact / Q000150:complications*; D004485:Eczema / Q000209:etiology* / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry; D005333:Fetus / Q000378:metabolism; D015236:HLA-C Antigens / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007413:Intestinal Mucosa / Q000196:embryology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D014066:Palatine Tonsil / Q000378:metabolism; D011565:Psoriasis / Q000378:metabolism*; D012867:Skin / Q000378:metabolism; D013194:Staining and Labeling; D014018:Tissue Distribution; D014162:Transfection
chemical_list: D015236:HLA-C Antigens; C038653:HLA-C*03 antigen; D015395:Histocompatibility Antigens Class I; D008070:Lipopolysaccharides