OBJECTIVE: The effect of oral cadmium (Cd) intake to influence contact skin allergies was examined, since it is known that Cd is a heavy metal that affects many tissues, including the skin, in which it disturbs homeostasis, thus resulting in inflammation and injury. METHODS: Male rats were evoked with experimental contact hypersensitivity reaction (CHS) to hapten dinitrochlorobenzene (DNCB), after prolonged (30 day) oral exposure to an environmentally relevant Cd dose (5 ppm). The ear cell population was analyzed with flow cytometry. Cytokine production by ear skin cells and the activity of skin-draining lymph node (DLN) cells were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Orally acquired Cd (5 ppm) increased CHS intensity only in Dark Agouti (DA) rats by affecting inflammatory responses in both the sensitization (an increase of IFN-γ and IL-17 cytokine production) and challenge (an increase of CD8 ⁺ and CD4 ⁺ cell number and TNF, IFN-γ and IL-17 cytokine production) phases. An increased CHS reaction was seen in Albino Oxford (AO) rats only at a high Cd dose (50 ppm), during the challenge phase (an increase of CD8 ⁺ and CD4 ⁺ cell number and TNF, IFN-γ and IL-17 cytokine production). CONCLUSION These novel data indicate that oral Cd intensifies the skin response to sensitizing chemicals such as DNCB.
Male ; Rats ; Animals ; Allergens/toxicity* ; Cadmium/toxicity* ; Dinitrochlorobenzene/toxicity* ; Interleukin-17 ; Cytokines

OBJECTIVESTo study the contact allergenic activities of trichloroethylene (TCE) and its three metabolites trichloroacetic acid, trichloroethanol and chloral hydrate.

METHODSA modified guinea pig maximization test (GPMT) was adopted. The skin sensitization (edema and erythema) was observed in trichloroethylene, trichloroacetic acid, trichloroethanol, chloral hydrate and 2,4-dinitrochlorobenzene.

RESULTSThe allergenic rate of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 71.4%, 58.3% and 100.0% respectively, and that of trichloroethanol and chloral hydrate was 0%. The mean response score of TCE, trichloroacetic acid and 2,4-dinitrochlorobenzene was 2.3, 1.1, 6.0 respectively. The histopathological analysis also showed an induction of allergenic transformation in guinea pig skin by both TCE and trichloroacetic acid.

CONCLUSIONTCE appears to be a strong allergen while trichloroacetic acid a moderate one. On the other hand, both trichloroethanol and chloral hydrate are weak sensitization potentials. Immunologic reaction induced by TCE might be postulated as the pathological process of this illness. Consequently, it is suggested that in the mechanism of Occupational Dermatitis Medicamentose-Like (ODML) induced by TCE, the chemical itself might be the main cause of allergy. As one of its metabolic products, trichloroacetic acid might be a subordinate factor.

Allergens ; toxicity ; Animals ; Chloral Hydrate ; toxicity ; Dermatitis, Allergic Contact ; etiology ; immunology ; Dermatitis, Irritant ; etiology ; immunology ; Ethylene Chlorohydrin ; analogs & derivatives ; toxicity ; Guinea Pigs ; Skin ; drug effects ; immunology ; Toxicity Tests ; Trichloroacetic Acid ; toxicity ; Trichloroethylene ; metabolism ; toxicity

OBJECTIVETo compare the sensitivity of Brown Norway rats (BN) with Guinea pigs (GP) as allergen assessment animal models.

METHODBN rats and GP were randomly assigned to 1 control group, 2 Bovine serum albumin group (BSA), respectively. Animals in BSA groups of BN rats and GPs were sensitized by intraperitoneal injection of 0.6% BSA 1 ml on day 1, 3, 5, respectively, and irritated by intravenous injection of 2.4% BSA 1 ml on day 7 and day 14 after the last sensitization, while the same volume of normal saline was given to control group on each time point mentioned above. The allergic reactions were scored within 1 h after each irritation treatment, and the sera of both BN rats and GPs were collected to detect IgE concentration by using ELISA. The sera were also applied for passive cutaneous anaphylaxis test (PCA test) in SD rats.

RESULTNo obvious allergic reactions were observed in BSA group of GPs after each irritation treat, however, the score of allergic response in BSA group of BN rats was evidently higher than that in control group after first irritation. PCA test by using sera from BSA group of BN rats after both irritations showed the strong positive result characterized as large amount of subcutaneous effusions of Evans blue in SD rats, however, the sera from BSA group of GP were negative in PCA test. Serum IgE concentration did not increase after each irritation in BSA group of both BN rats and GP.

CONCLUSIONBN rats were more sensitive than GPs on initiative systemic anaphylaxis test and passive cutaneous anaphylaxis test. Meanwhile, BN rats has an advantage in experimental treatment compared with Guinea pigs.

Allergens ; administration & dosage ; toxicity ; Anaphylaxis ; chemically induced ; Animals ; Guinea Pigs ; Hypersensitivity ; etiology ; Male ; Models, Animal ; Rats ; Rats, Inbred BN ; Rats, Sprague-Dawley

OBJECTIVETo investigate whether cellular immunity and humoral immunity are involved in trichlorethylene (TCE)-induced mixed allergy, then provide the scientific basis for the mechanism of this disease.

METHODSGuinea pigs and rats were tested for this study by application of guinea pig maximization test (GPMT), the animals were randomly divided into negative control, positive control and TCE treatment groups. Animals of these groups were administrated with olive oil, 2, 4-dinitrochlorobenzene (DNCB), and TCE, respectively, by intradermal injection. After TCE administration, rat peripheral blood samples were collected by flow cytometry to detect lymphocytes CD3⁺, CD4⁺, CD8⁺. Guinea pig peripheral blood samples were collected to detect the levels of IgG, IgA, IgM, C3, C4, and the spleens were taken out from guinea pigs after various treatment, mRNA expression of GATA3, T-bet, CTLA4 and Foxp3 in lymphocytes of guinea pig spleen was detected by real-time fluorescent PCR assay. Additionally, TCE allergic dermatitis patients were selected for the study, the peripheral blood samples were collected from the TCE patients group and control group, quantitative PCR was applied to detect mRNA expression of immune-related genes Foxp3, GATA3, CTLA4, T-bet.

RESULTSTCE induced obvious skin allergic reaction in guinea pigs, the sensitization rate was 83.3%, IgG levels in TCE group and positive control increased significantly. Additionally, mRNA expression levels of GATA3, T-bet, CTLA4 significantly elevated in TCE group and positive control, but Foxp3 mRNA levels decreased. The lymphocytes CD3⁺ ratio in TCE group and positive control of rats was higher than that in negative control, we found that there was no statistical difference of CD4⁺, CD8⁺, CD4⁺/CD8⁺ between TCE group and negative control of rats. The mRNA expression levels of Foxp3, GATA3, CTLA4 in TCE patients increased by 115%, 97%, 241%, respectively as compared with the control, T-bet levels decreased by 47%when compared with the control.

CONCLUSIONSTCE could induce obvious changes of cellular immunity and humoral immunity in guinea pigs, rats, and TCE patients, these findings indicated that TCE-induced immunological disorder belongs to the mixed allergy with involvment of cellular immunity and humoral immunity, the mixed allergy might be type IV and type II allergy.

Allergens ; Animals ; CTLA-4 Antigen ; Guinea Pigs ; Humans ; Hypersensitivity ; Immunity, Cellular ; drug effects ; Immunity, Humoral ; drug effects ; Lymphocytes ; RNA, Messenger ; Rats ; Spleen ; Trichloroethylene ; toxicity

Gap junction channels formed with connexins directly link to the cytoplasm of adjacent cells and have been implicated in intercellular signaling. Connexin 37 (Cx37) is expressed in the gas-exchange region of the lung. Recently, Cx37 has been reported to be involved in the pathogenesis of inflammatory disease. However, no data are available on the role of Cx37 in allergic airway inflammatory disease. In the present study, we used a murine model of ovalbumin (OVA)-induced allergic airway disease and primary murine epithelial cells to examine the change of Cx37 in allergic airway disease. These mice develop the following typical pathophysiological features of asthma: airway hyperresponsiveness, airway inflammation, and increased IL-4, IL-5, IL-13, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, eotaxin, and RANTES levels in lungs. Cx37 protein and mRNA expression were decreased in OVA-induced allergic airway disease. Immunoreactive Cx37 localized in epithelial layers around the bronchioles in control mice, which dramatically disappeared in allergen-induced asthmatic lungs. Moreover, the levels of Cx37 protein in lung tissues showed significantly negative correlations with airway inflammation, airway responsiveness, and levels of Th2 cytokines in lungs. These findings indicate that change of Cx37 may be associated with the asthma phenotype.
Airway Resistance ; Allergens/toxicity ; Animals ; Asthma/etiology/genetics/immunology/*metabolism ; Base Sequence ; Bronchoalveolar Lavage Fluid/cytology ; Cell Adhesion Molecules/metabolism ; Cells, Cultured ; Chemokines/metabolism ; Connexins/genetics/*metabolism ; Cytokines/metabolism ; DNA Primers/genetics ; Disease Models, Animal ; Epithelial Cells/metabolism ; Female ; Lung/immunology/metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Ovalbumin/immunology/toxicity ; RNA, Messenger/genetics/metabolism ; Trachea/metabolism