摘要:

AbstractIn recent years, it has become apparent that IL‐7, originally characterized as a growth factor for pre‐B lymphocytes. also has important implications for the skin. Keratinocytes have been shown to produce IL‐7, which in turn can elicit a variety of biological responses on several cell types residing in the skin. IL‐7 has been demonstrated to augment the cytolytic activity of cytotoxic T cells (CTL) and natural killer (NK) cells against various neoplastic targets indcluding melanoma cells. Proliferation and long‐term survival of murine dendritic epidermal T lymphocytes (DETC)in vitrois supported by IL‐7. IL‐7 also induces secretion of inflammatory cytokines by monocytes/macrophages and renders these cells to become tumoricidal against melanoma cells. Normal and malignant melanocytes respond to IL‐7 with increased expression of intercellular adhesion molecule (ICAM‐I). In addition, IL‐7 has been shown to act as growth factor for Sczary cells, suggesting a röle of keratinocyte‐derived IL‐7 in the pathogenesis of cutaneous T cell lymphoma. Because of the potentin vitroimmunomodulatory effects of IL‐7 which have been confirmed in mouse tumor models, IL‐7 may become a valuable additional agent to immunotherapeutical regimens currently studied in patients with advanced melanoma. This review summarizes our present knowledge about the molecular and immunological properties of IL7 with emphasis on the effects of that cytokine within the cutaneous compartment and the potentical cli

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00107.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractKeratinocyte growth factor (KGF) and its receptor (KGFR) are thought to play important roles in normal keratinocyte growth and differentiation. Since UVB radiation is known to influence keratinocyte growth, we sought to determine whether UVB would alter the expression of KGF and KGFR. Using a reverse‐transcription coupled polymerase chain reaction (RT‐PCR). the present study examined the expression of KGF and KGFR mRNA in cultured normal human keratinocytes exposed to UVB irradiation. Total cellular RNA was extracted from cultured keratinocytes at various time points after irradiation, reverse transcribed and used for PCR amplification using primers specific for KGF and KGFR. Constitutive expression of KGFR mRNA, but not KGF mRNA, was detected in normal cultured human keratinocytes. After UVB irradiation at 300 J/m2, the KGF mRNA remained undelectable while the KGFR mRNA level was significantly decreased. The downregulation of KGFR mRNA expression was also confirmed by Northern blot analysis. Immunohistochemical studies demonstrated a decreased positive signal of KGFR in human keratinocytes after UVB irradiation. Our results suggest a possible role for the KGF‐KGFR signalling pathway in the skin after exposure to UVB, and that UVB‐induced growth inhibition of keratinocytes in hyperproliferative skin disorders may be related to downregulation

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00108.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractGenerally, many wrinkles form on the human face, and temporary wrinkles eventually become permanent. We evaluated the effects of temporary skin fixation on wrinkle formation after UVB irradiation using the back skin of hairless mice. In the group treated with UVB irradiation immediately after production using cyanoacrylate resin of an artificial groove parallel to the midline, wrinkles formed parallel to the midline, an uncommon direction for wrinkle formation in this mouse model. These wrinkles did not disappear even when the skin was stretched. No such changes were observed in the group in which only the temporary groove alone was produced without UVB irradiation. In 3‐D surface parameter analysis, all roughness parameters in the group treated with UVB irradiation immediately after production of an artificial groove were significantly increased relative to the age‐matched control group. In contrast, no differences were observed between the group in which only the temporary groove alone was produced without UVB irradiation and age‐matched controls. The results of this study suggest that both a temporary groove in the skin and UVB irradiation are necessary for wrinkle formation in the back skin of hairless

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00109.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractEpidermal keratinocytes in culture have been shown to produce many cytokines, and their proteins have been identified in skin tissue samples. It has therefore been assumed that these cytokines are transcribed in vivo by the epidermis in response to contact allergens. In this report, in situ hybridization was used to detect the messenger RNAs for interleukin‐1 alpha (IL‐1α), interleukin‐1 beta (IL‐1β) and tumour necrosis factor‐alpha (TNF‐α) in samples of human skin prior to and at various times after application of urushiol, the immunogenic component of poison ivy/oak. In sensitive subjects, IL‐1α and TNF‐α mRNAs showed a progressive increase in transcript levels that paralleled the clinical and histological features of the inflammatory process. The time–course of the IL‐1β response differed from that of IL‐1α and TNF‐α, in that there was an early (by 6 h after urushiol administration) elevation in IL‐1 β mRNA that occurred before there was evidence of inflammation and had returned to background levels by 72 h when the reaction had reached its peak. In contrast to urushiol‐sensitive subjects, urushiol‐allergic individuals did not exhibit an increase in IL‐1α. IL‐1β or TNF‐α mRNA levels. The data provide evidence for an in vivo role for epidermal IL‐1α, IL‐1β and TNF‐α transcription in the regulation of IL‐lβ and TNF‐α polypeptide level

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00110.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThe exposure of dermal equivalent, i.e., fibroblasts cultured in a 3‐dimensional collagen matrix to realistic doses of UVA (≤ 200 kJ/m2), results in a lipid peroxidation process as evidenced by the release of thiobarbituric acid‐reactive substances in the supernatant. This peroxidalive process is shown to be associated with the presence of libroblasts and is inhibited by pre‐incubation with vitamin E. the well‐known chain‐breaking antioxidant. Moreover, the UVA irradiation triggers cyclotoxic effects which can also be reversed by preincubation with vitamin E. While the peroxidation extent is similar for fibroblasts cultured in monolayers or in dermal equivalent, the cytotoxic response to UVA is more pronounced in dermal

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00111.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractTattooing is an act of permanent marking of the skin with indelible patterns by pricking and inserting pigments. Langerhans cells (LCS) are dendritic cells normally present in suprabasal layers of the epidermis of the skin. To assess whether there were any effects caused by the tattooing on Langerhans cell population and cutaneous nerves, skin from affected areas (n=15) was compared with controls (n=10). Frozen sections were immunostained with antisera to S‐100. No discernible change either in distribution or in number of Langerhans cells and nerves was seen upon comparison with control skin taken from different areas, but all of the specimens taken from affected areas had a significant increase in the number of Langerhans cells (p<0.001) even after several years of tattooing with no change in the cutaneous nerves. Thus, the study shows persistent stimulation of Langerhans cell population in tattooed ski

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00112.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractExposure of mice to UVB radiation down‐regulates the induction of contact hypersensitivity (CHS) responses to haptens applied to the site of irradiation. Concomittantly, the activity of antigen‐presenting cells (APC) in the draining lymph nodes is decreased, and T lymphocytes that suppress the induction of CHS are induced. We assessed the röle of DNA damage in modulation of the CHS response by UV irradiation by applying liposomes containing T4 endonuclease V (T4N5) to the UV‐irradiated skin. Liposomal T4N5. which increases the rate of repair of cyclobutyl pyrimidine dimers (CPD) in DNA. prevented the reduction in the CHS response, the impairment in APC function, and the induction of transferrable immune suppression. Liposomes containing heat‐inactivated T4N5 did not restore immune responsiveness. In this model, hapten‐bearing APC from unirradiated mice also fail to induce CHS upon injection into UV‐irradiated recipients. This systemic effect of UV irradiation on APC function was also prevented by application of liposomes containing active, but not inactive, T4N5. These studies support the hypothesis that DNA damage is an essential initiator of one or more steps leading to impaired immune responsiveness after UV irradiation. They further imply that the release of cytokines that modulate APC function after UV irradiation is triggered b

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00113.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

AbstractThebcl‐2proto‐oncogene, which is involved in the regulation of apoptosis, is expressed in a wide varity of fetal and adult tissues. We and others have demonstrated recently that in the human skin melanocytes, nevus cells and melanoma cells expressbcl‐2constitutively. In the present study, we have analysed the expression ofbcl‐2in Merkel cells and in Merkel cell carcinomas. In 2 colour immunofluorescence staining, normal human Merkel cells as identified by the expression of cytokeratins 8, 18 and 20, were also anti‐bcl‐2positive. Staining of paraffin sections of Merkel cell carcinomas with an anti‐bcl‐2monoclonal antibody revealed strong bcl‐2 protein immunoreactivity in all 5 tumors tested. Serial sections of Merkel cell carcinomas stained with the monoclonal antibodies CK 20. CAM 5.2, anti‐neuron‐specific enolase and anti‐bcl‐2 showed that the anti‐bcl‐2reactive cells were indeed tumor cells. Our data demonstrate for the first lime, that normal human Merkel cells and Merkel cell carcinomas expresshcl‐2constitutively. Considering the biological function of thebcl‐2proto‐oncogene, i.e., its anti‐apoptotic effect, it is conceivable that in the near future, modulations of the expression of this protein may offer a new strategy in the therapy ofbcl‐2express

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00114.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00115.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0906-6705    

DOI:10.1111/j.1600-0625.1996.tb00116.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY