title: Pityrosporum orbiculare-reactive T-cell lines in atopic dermatitis patients and healthy individuals.
abstract: The yeast Pityrosporum orbiculare is one of the factors that may contribute to atopic dermatitis (AD). In the present study we compared the T-cell response to P. orbiculare in 12 AD patients with specific immunoglobulin (Ig)E antibodies (Ab) in serum against P. orbiculare with that of six non-atopic healthy controls. Freshly isolated peripheral blood mononuclear cells (PBMC) were cultured for 3 days in the presence of P. orbiculare extract. The proliferative response as measured by [3H]-thymidine incorporation was significantly higher in the AD patients than in the healthy controls (P < 0.05). Furthermore, significantly higher levels of interleukin (IL)-5 (P < 0.05), as analyzed by ELISA, were produced by PBMC from the AD patients compared to the healthy controls. Pityrosporum orbiculare-reactive T-cell lines (TCL) established by P. orbiculare stimulation of PBMC for 11 days produced significantly higher levels of IL-4 and IL-5 after stimulation with anti-CD3 Ab and showed a higher IL-4/interferon (IFN)-gamma ratio (P < 0.05) in the AD patients compared to the healthy controls. The higher proliferative PBMC response to P. orbiculare and the Th2-like cytokine production by P. orbiculare-stimulated TCL from AD patients indicate that P. orbiculare may play a role in maintaining skin inflammation in AD.
authors.affiliation: Department of Laboratory Medicine, Karolinska Institute and Hospital, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Tengvall Linder
authors.forename: C
authors.initials: C
authors.lastname: Johansson
authors.forename: A
authors.initials: A
authors.lastname: Bengtsson
authors.forename: L
authors.initials: L
authors.lastname: Holm
authors.forename: B
authors.initials: B
authors.lastname: Härfast
authors.forename: A
authors.initials: A
authors.lastname: Scheynius
mesh_terms: D000293:Adolescent; D000328:Adult; D002455:Cell Division; D002460:Cell Line; D002478:Cells, Cultured; D003876:Dermatitis, Atopic / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D015848:Interleukin-5 / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008290:Malassezia / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D015848:Interleukin-5; D015847:Interleukin-4; D007371:Interferon-gamma