Vitiligo is an acquired, progressive depigmenting disorder of unknown etiology. In this study, to clarify pathogenesis of vitiligo, the marginal skin of actively spreading and stable vitiligo was examined using ICAM-1, HLA-DR, CD4 and CD8 monoclonal antibodies. In immunohistochemical study, ICAM-1 was expressed in four of five epidermis in active lesions, but not in stable lesion. Dermal ICAM-1 was also expressed in all active and stable lesions. HLA-DR was also expressed in all active epidermis in active lesions, but two of five epidermis in stable lesion. Dermal HLA-DR was also expressed in all active and stable lesion. CD4 lymphocytes were expressed more strongly in active lesion, but CD8 lymphocytes were not different in both lesions. There was no significant difference of degree of positivity with CD4 and CD8 in normal control specimens. In conclusion, we think that ICAM-1 and HLA-DR expression, cytokines released from keratinocytes, melanocytes or lymphocytes and infiltration of activated T-lymphocytes play an important role in disease activity.
Antigens, CD4/metabolism ; Antigens, CD8/metabolism ; Comparative Study ; HLA-DR Antigens/metabolism ; Human ; Immunohistochemistry ; Intercellular Adhesion Molecule-1/metabolism ; Skin/immunology ; Vitiligo/*immunology

To compare the difference in tumor immunity and autoimmunity elicited by adenovirus (Ad) encoding human or murine tyrosinase-related protein 2 (AdhTRP2 or AdmTRP2), and to find the most effective way to induce immunity by AdhTRP2 or AdmTRP2, C57BL/6 mice were immunized with AdhTRP2 or AdmTRP2 intramuscularly at different doses of 10(5), 10(6), 10(7) and 10(8) separately (10 mice for each dose). Two weeks after the immunization, in vivo CTL assay and intracellular staining (ICS) of IFN-gamma were carried out to analyze the dose-effect relationship. Tumor growth and vitiligo (as an sign of autoimmunity) were observed until 3 months after challenge with 10(5) B16F10 tumor cells. The results showed that Ad encoding AdmTrp2 induced weak tumor immune response. Similar immunization with AdhTrp-2 elicited stronger protective immunity. CTL activity and IFN-gamma-produced CD8+T cells were directly proportional to dose of AdhTrp2 or AdmTrp2. Moreover, AdhTrp2 group showed tumor rejection in 100% of challenged mice till the end of 3rd month while 60% of mice immunized with AdmTrp2 were protected against tumor. In the whole process of this experiment, no vitiligo was observed in mice immunized either with AdhTrp2 or AdmTrp2. It is concluded that anti-melanoma responses induced by genetic vaccination expressing xenoantigens breaks immune tolerance effectively and is able to elicit strong antigen-specific cytotoxic T cell response without vitiligo.
Adenoviridae/metabolism ; Antineoplastic Agents/*pharmacology ; Cell Line, Tumor ; Cytokines/metabolism ; Immune System ; Immune Tolerance ; Interferon-gamma/metabolism ; Intramolecular Oxidoreductases/*biosynthesis ; Intramolecular Oxidoreductases/*genetics ; Mice, Inbred C57BL ; T-Lymphocytes, Cytotoxic/*metabolism ; Vitiligo/*metabolism

Several chemical compounds can restore pigmentation in vitiligo through mechanisms that vary according to disease etiology. In the present study, we investigated the melanogenic activity of six structurally distinct compounds, namely, scopoletin, kaempferol, chrysin, vitamin D, piperine, and 6-benzylaminopurine. We determined their effectiveness, toxicity, and mechanism of action for stimulating pigmentation in B16F10 melanoma cells and in a zebrafish model. The melanogenic activity of 6-benzylaminopurine, the compound identified as the most potent, was further verified by measuring green fluorescent protein concentration in tyrp1 a: eGFP (tyrosinase-related protein 1) zebrafish and mitfa: eGFP (microphthalmia associated transcription factor) zebrafish and antioxidative activity. All the tested compounds were found to enhance melanogenesis responses both in vivo and in vitro at their respective optimal concentration by increasing melanin content and expression of TYR and MITF. 6-Benzyamino-purine showed the strongest re-pigmentation action at a concentration of 20 μmol·Lin vivo and 100 μmol·Lin vitro, and up-regulated the strong fluorescence expression of green fluorescent protein in tyrp1a: eGFP and mitfa: eGFP zebrafish in vitro. However, its relative anti-oxidative activity was found to be very low. Overall, our results indicated that 6-benzylaminopurine stimulated pigmentation through a direct mechanism, by increasing melanin content via positive regulation of tyrosinase activity in vitro, as well as up-regulating the expression of the green fluorescent protein in transgenic zebrafish in vivo.
Alkaloids ; chemistry ; pharmacology ; Animals ; Benzodioxoles ; chemistry ; pharmacology ; Benzyl Compounds ; chemistry ; pharmacology ; Cholecalciferol ; chemistry ; pharmacology ; Flavonoids ; chemistry ; pharmacology ; Humans ; Kaempferols ; chemistry ; pharmacology ; Melanins ; genetics ; metabolism ; Monophenol Monooxygenase ; genetics ; metabolism ; Pigmentation ; drug effects ; Piperidines ; chemistry ; pharmacology ; Polyunsaturated Alkamides ; chemistry ; pharmacology ; Purines ; chemistry ; pharmacology ; Scopoletin ; chemistry ; pharmacology ; Vitiligo ; drug therapy ; enzymology ; metabolism ; Zebrafish