ABSTRACT
BACKGROUND: Allergic contact dermatitis (ACD), which is accelerated by interferon (IFN)-γ and suppressed by interleukin (IL)-10 as regulators, is generally self-limited after removal of the contact allergen. Adipose tissue-derived multipotent mesenchymal stem cells (ASCs) potentially exert immunomodulatory effects. Considering that subcutaneous adipose tissue is located close to the site of ACD and includes mesenchymal stem cells (MSCs), the MSCs in adipose tissue could contribute to the self-limiting course of ACD. OBJECTIVE: The aims of the present study were to elucidate the effects of MSCs in adipose tissue on ACD and to examine any cytokine-mediated mechanisms involved. METHODS: Ear thickness in a C57BL/6 mouse model of ACD using contact hypersensitivity (CHS) elicited by 2,4,6-trinitro-1-chlorobenzene was evaluated as a marker of inflammation level. Five and nine mice were injected with ASCs and phosphate-buffered saline (PBS), respectively. After ASC or PBS injection, real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were performed. RESULTS: Histology showed that CHS was self-limited and ear thickness was suppressed by ASCs in a dose-dependent manner. IFN-γ expression in the elicited skin site and regional lymph nodes was significantly lower in ASC-treated mice than in control mice. IL-10 expression did not differ between treated and control mice. The suppressive effects of ASCs on CHS response did not differ between IL-10 knock-out C57BL/6 mice and wild-type mice. CONCLUSION: The present findings suggest that MSCs in adipose tissue may contribute to the self-limiting course of ACD through decreased expression of IFN-γ, but not through increased expression of IL-10.
Subject(s)
Animals , Mice , Adipose Tissue , Dermatitis, Allergic Contact , Dermatitis, Contact , Ear , Enzyme-Linked Immunosorbent Assay , Inflammation , Interferons , Interleukin-10 , Interleukins , Lymph Nodes , Mesenchymal Stem Cells , Picryl Chloride , Skin , Subcutaneous FatABSTRACT
BACKGROUND: The type 2 deviated immunological state is predominant in lepromatous leprosy. Erythema nodosum leprosum (ENL) is an immune-complex mediated reaction that typically occurs in lepromatous leprosy. To date, the serum levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-2 receptor, IL-10, IL-1beta, IL-1 receptor antagonist and monocyte chemoattractant protein-1 (MCP-1) were reported to be higher in lepromatous leprosy. TNF-alpha is also known to be higher in ENL, which is reduced after thalidomide treatment. However the serum type 2 chemokine levels in lepromatous leprosy patients have not been reported. METHODS: The serum levels of the type 2 chemokines such as thymus and activation-regulated chemokine (TARC), macrophage-derived chemokine (MDC) and eotaxin together with IL-12 and IL-10 in the sera from leprosy patients were detected using an enzyme-linked solvent assay (ELISA) method. RESULTS: The Serum TARC, MDC, eotaxin, IL-10 and IL-12 levels in lepromatous leprosy patients were not significantly different from the normal control levels. The serum levels were not significantly different between the paucibacillary group and multibacillary group. The serum TARC or MDC levels in the ENL patients were more reduced after a treatment containing thalidomide. CONCLUSION: The type 2 chemokines are not related to the severity of lepromatous leprosy. The larger reducing effect of the TARC or MDC levels in ENL patients by a treatment containing thalidomide suggests the potential role of these chemokines in the development of ENL and the therapeutic mechanism of thalidomide.