The change of langerhans cells,la+kerationocytes and thy-1+dendritic epidermal cell in allergic contact dermatitis and irritant contact dermatitis / 대한피부과학회지

ABSTRACT

BACKGROUND: Langerhans cells (LC), keratinocytes and Thy-1+ dendritic epidermal cells(DEC) are epidermal cells which are known to have important roles in inflammatory or immunologic skin disorders. Allergic contact dermatitis(ACD) is a prototype of a delayed hypersensitive reaction in which LC, keratinocytes and T lymphocytes play an important role. The role of LC in ACD is well known, but the role of Thy-1+ DEC is not yet fully revealed. Futhermore, the mechanism of irritant contact dermatitis(ICD) is not known and more study is required on the interaction between these epidermal cells in ICD. OBJECTIVE: The aim of this study is to observe the changes of these cells in ACD and ICD and to discuss their possible roles in the disease precess. MEHTODS We evoked ACD with DNFB and ICD with croton oil in BALB/c mice and observed the morphologic changes of LC, Ia+ keratinocytes, and Thy-1+ DEC by immunoperoxidase staining when the inflammation was at its peak and at the resolution state. RESULTS: 1. In the control group, LC were evenly distributed and their average number was 1147+/-132/mm*. Thy-1+ DEC were slightly bigger than LC and showed uneven distribution. The average number of Thy-1+ DEC was 57+/-69/mm* Ia+ keratinocytes did not appeared. 2. On the 1st day of DNFB challenge, the number of LC was significantly decreased and their size and dendritic processes were increased when compared to those of the control group. Most of the keratinocytes showed Ia antigen expression on their surfaces. 3. On the 12th day of DNFB challenge, no significant changes in the number and morphologyof LC were noted when compared to the cotrol group, Ia+ keratinocytes were not observed. 4. there were no significant changes in the number and morphology of Thy-1+ DEC in ACD on the 1st and 12th day after DNFB challenge. 5. On the 2nd day after croton oil application, the number of LC was significantly decreased but the morphology not significantly changed. Ia+ keratinocytes were not observed. 6. On the 20th day after croton oil application, the number of LC was significantly increased but the morphology was not significantly changed. Ia+ keratinocytes were not observed. 7. There were no significant changes in th number and morphology of Thy-1+ DEC in ICD on the 2nd and 20th day after application of croton oil. Ia+ keratinocytes were not observed. CONCLUSION: In can be deduced that the LC have important roles in the mechanisms of both ACD and ICD reactions. Ia+ keratinocytes have an important role mainlyin the inflammatory precess of ACD. In addition, since the changes of the number of Langerhans cells in ACD and ICD showed different time courses and Ia+ keratinocytes appeared only in ACD, we hypothesized that different pathways of inflammation exist in ACD and ICD, and different cytokines may be responsible. It is probable that Thy-1+ DEC does not have any significant role in the inflammatory process of both ACD and ICD.