metallothionein and Dermatitis--Allergic-Contact

Two principal types of stress protein, heat shock proteins (hsps) and metallothionein (MT), are induced in cells responding to a variety of stresses. They play an important role in protecting cells from these stresses. However, many reports indicate that antibodies to hsps are present in human serum and are associated with several autoimmunity diseases. Metals, which are commonly allergenic to humans, induce both MT and hsp70 (one of the hsps family). Until now, there has been no report of any antibody to MT in human serum. In the present study, serum samples from healthy controls (Group I), and patients suffering from atopic dermatitis without (Group II) or with (Group III) metal allergy, were measured for antibodies to MT and hsp70, using an enzyme-linked immunosorbent assay (ELISA). Metal allergy was confirmed by patch testing. We first found that antibody to MT exists in human serum. We also found a high positive frequency of antibody to MT (51.3%) and to hsp70 (43.6%) in the sera of Group III, compared to those of Group I (3.8% and 5.1%) or Group II (6.4% and 5.1%). Furthermore, there was a strong positive correlation between antibody to MT and antibody to hsp70 in Group III (P = 0.0013), but not in Group I and Group II. Our results indicate that antibody to MT exists in human serum, as do antibodies to hsps, and suggest that elevated levels of MT and hsp70 antibodies are associated with metal allergy in atopic patients.

Topics: Adult; Autoantibodies; Dermatitis, Allergic Contact; Female; HSP70 Heat-Shock Proteins; Humans; Male; Metallothionein; Metals; Middle Aged; Patch Tests

To investigate the chronic hypersensitivity (CHS) to dinitrofluorobenzene (DNFB) in metallothionein gene knocked-out (MT -/-) mice and wild mice (MT +/+) with homologous genes.. Mice were sensitized by applying DNFB on abdominal skin and CHS was induced on right ears. The CHS was observed by ear swelling.. In comparison with metallothionein--null mice, the ear swelling of normal control wild mice was significantly greater. (P < 0.05, Students t test).. Metallothioneins play an important role in the CHS. Metallothionein gene knocked-out (MT -/-) mice express less inflammation of CHS.

Topics: Animals; Dermatitis, Allergic Contact; Dinitrofluorobenzene; Inflammation; Metallothionein; Mice; Mice, Knockout; Skin

The expression and the distribution of metallothioneins (MT)-I and II isoforms were evaluated in 5 healthy volunteers and in 16 subjects with positive patch test reactions to various compounds. Skin specimens taken both from the healthy skin of the back and at positive patch test sites (at 48 h), were treated using a 3-step indirect immunoperoxidase procedure with a mouse monoclonal IgG1 antibody reactive against I and II isoforms of human, rat and horse MT. MT were expressed in the basal layer of the healthy skin of both controls and sensitive subjects, without any significant difference. At positive patch test sites, there was an overexpression of MT in basal and suprabasal layers of the epidermis. Overexpression of MT, related to the degree of the inflammatory reactions elicited by the penetrating compounds was observed in the dermis. The cells expressing MT in the dermis were mostly T lymphocytes and cells with dendritic morphology which positively stained in part for CD34 and in part for XIIIa markers and negatively for KP1, S100 and HLA-DR. Taken together, these results seem to indicate that MT represent a constitutive mechanism of defence expressed by different types of cells in the skin, which is triggered by contact with both metallic and non-metallic compounds. The biological significance of MT in the skin remains to be elucidated. Our preliminary findings do not permit evaluation of whether these nearly ubiquitous proteins exert their cytoprotective effects in the skin acting simultaneously as antioxidant, metal binding or zinc suppliers, or if they display these activities mainly depending on the nature of the penetrating substances.

Topics: Adolescent; Adult; Antibodies, Monoclonal; Dermatitis, Allergic Contact; Humans; Immunoenzyme Techniques; Male; Metallothionein; Middle Aged; Patch Tests; Protein Isoforms; Skin; Up-Regulation