Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Exp Dermatol ; 34(1): 61-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19018787

RESUMO

BACKGROUND: Although dry skin and T cell-dependent disease exacerbation are characteristic features of atopic dermatitis (AD), the involvement of T cells in the development of dry skin remains unclear. AIMS: We aimed to elucidate the role of T cells in the development of dry skin in DS-Nh mice as a model for AD, and to evaluate this skin condition pharmacologically. METHODS: We prepared DS-Nh mice harbouring a T-cell receptor (TCR)Vbeta(a) haplotype with a central deletion in the TCRBV gene segments, and mice harbouring a TCRVbeta(b) haplotype without any deletion. We analysed the TCRVbeta chain usage and cytokine response to antimouse CD3 monoclonal antibodies in the splenocytes from the two mouse substrains. Transepidermal water loss (TEWL) was measured, and histochemical examination of these mice was carried out. Finally, a pharmacological analysis using loratadine was also performed to evaluate the features of spontaneous dry skin in DS-Nh mice as a model of AD. RESULTS: Although the deletion of TCRBV gene segments in the TCRVbeta(a) haplotype yielded different representations of each TCRVbeta mRNA, this deletion did not evoke distinct cytokine profiles in the splenocytes compared with those of mice with the TCRVbeta(b) haplotype. Furthermore, our results indicated that the onset of dry skin occurred earlier in mice with TCRVbeta(b) than in those with TCRVbeta(a). Pharmacologically, AD-like dry skin in DS-Nh with TCRVbeta(b) mice is susceptible to an H1 blocker. CONCLUSIONS: A specific lymphocyte subpopulation bearing T-cell receptors may be responsible for loratadine-responsive dermatitis in DS-Nh mice.


Assuntos
Dermatite Atópica/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Animais , Citocinas/metabolismo , Dermatite Atópica/genética , Modelos Animais de Doenças , Haplótipos , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos , RNA Mensageiro/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/genética
2.
Immunology ; 118(3): 293-301, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16827890

RESUMO

Itching is one of the major clinical symptoms in atopic dermatitis (AD) and complicates the management of this pathological condition. An animal model of AD-like pruritus would contribute to a better understanding of AD and could lead to the development of safe and effective antipruritic agents. DS non-hair (DS-Nh) mice raised under conventional conditions spontaneously develop pruritus, which is associated with a dermatitis similar to human AD. There is a significant positive correlation between disease severity and the period of scratching behaviour in DS-Nh mice. In the present study, we found that levels of histamine and nerve growth factor (NGF) in serum and/or skin tissue were higher in DS-Nh mice with AD-like dermatitis than in age-matched mice without dermatitis. The histopathological data indicated that nerve fibres extend into and mast cells infiltrate the surrounding area of the skin lesion. NGF production by XB-2 cells, which was derived from mouse keratinocytes, was enhanced by histamine via the H1 receptor. We also found that prolonged treatment with an H1-antagonist was effective against pruritus through depression of the production of NGF, which is thought to be generated by keratinocytes. We conclude that DS-Nh mice can serve as a suitable model for gaining a better understanding of pruritus in AD, and that prolonged treatment with an H1-antagonist may be beneficial in patients with AD-associated pruritus.


Assuntos
Dermatite Atópica/complicações , Modelos Animais de Doenças , Prurido/etiologia , Animais , Antipruriginosos/uso terapêutico , Células Cultivadas , Dermatite Atópica/metabolismo , Dermatite Atópica/patologia , Histamina/metabolismo , Histamina/farmacologia , Antagonistas não Sedativos dos Receptores H1 da Histamina/uso terapêutico , Imunoglobulina E/sangue , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Loratadina/uso terapêutico , Masculino , Mastócitos/patologia , Camundongos , Camundongos Endogâmicos , Fator de Crescimento Neural/biossíntese , Fator de Crescimento Neural/metabolismo , Prurido/tratamento farmacológico , Prurido/metabolismo , Pele/metabolismo , Organismos Livres de Patógenos Específicos
3.
Immunology ; 108(4): 562-9, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12667219

RESUMO

DS-Nh mice raised under conventional conditions spontaneously develop dermatitis similar to human atopic dermatitis (AD), which is associated with staphylococcal infection. In the present study, we show that Staphylococcus aureus producing staphylococcus exotoxin C (SEC) was recovered from the culture of the skin lesions of DS-Nh mice with AD-like dermatitis and that the serum levels of anti-SEC antibodies from these mice were elevated. We describe here how to promote experimental AD by epicutaneous injection with SEC-producing S. aureus to DS-Nh mice. In order to assess the role of SEC in the pathogenesis of AD, the mitogenic activity, TCRBV repertoire analysis and the production of IL-4 and IFN-gamma from spleen mononuclear cells (MNC) from DS-Nh stimulated by SEC were compared with those due to SEA, SEB and TSST. The weakest was the mitogenic activity of SEC, and higher IL-4 responses and lower IFN-gamma responses to SEC showed correlation with TCRBV8S2-positive T cells, which were selectively stimulated by SEC. We also demonstrate that SEC-producing S. aureus was able to survive in DS-Nh after intradermal injection. These results suggest a possible role for SEC in the pathogenesis of AD through host-S. aureus relationships.


Assuntos
Dermatite Atópica/microbiologia , Enterotoxinas/imunologia , Infecções Estafilocócicas/complicações , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/imunologia , Divisão Celular/imunologia , Células Cultivadas , Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Modelos Animais de Doenças , Enterotoxinas/biossíntese , Feminino , Interferon gama/biossíntese , Interleucina-4/biossíntese , Linfonodos/microbiologia , Masculino , Camundongos , Baço/imunologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo , Superantígenos/imunologia
4.
J Dermatol Sci ; 26(3): 209-16, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11390206

RESUMO

High-dose ultraviolet B (UVB) irradiation is known to induce apoptosis of keratinocytes, but low-dose UVB dose not. In this paper we present evidence that low-dose UVB can induce TNF-alpha-dependent apoptosis of keratinocytes. In our study, 5 mJ/cm(2) doses of UVB were not sufficient by themselves to induce apoptosis of cultured human keratinocytes, but 20 mJ/cm(2) doses of UVB were. The combination of 5 mJ/cm(2) doses of UVB and exogenous TNF-alpha (15 ng/ml) induced significant apoptosis of keratinocytes, although exogenous TNF-alpha without UVB did not. This phenomenon was accompanied by enhanced clustering of tumor necrosis factor receptor 1 (TNFR1). TNF-alpha's promotion of the induction of apoptosis by low-dose UVB was seen until 30 min after irradiation but not at 1 h. We confirmed this finding using a skin organ culture system. UVB (20 mJ/cm(2)), which did not induce transformation of epidermal keratinocytes into sunburn cells, induced apoptosis when TNF-alpha was added to the culture medium. These results suggest that one of the possible mechanisms of inducing keratinocyte apoptosis by low-dose UVB and TNF-alpha is that low-dose UVB augments ligand-binding-induced TNFR1 clustering, resulting in increased apoptotic cell death.


Assuntos
Apoptose , Queratinócitos/efeitos dos fármacos , Queratinócitos/efeitos da radiação , Fator de Necrose Tumoral alfa/fisiologia , Raios Ultravioleta , Antígenos CD/efeitos dos fármacos , Antígenos CD/fisiologia , Antígenos CD/efeitos da radiação , Relação Dose-Resposta à Radiação , Humanos , Técnicas de Cultura de Órgãos , Agregação de Receptores , Receptores do Fator de Necrose Tumoral/efeitos dos fármacos , Receptores do Fator de Necrose Tumoral/fisiologia , Receptores do Fator de Necrose Tumoral/efeitos da radiação , Receptores Tipo I de Fatores de Necrose Tumoral , Pele/citologia , Pele/efeitos dos fármacos , Pele/efeitos da radiação
5.
Int Immunol ; 5(12): 1619-27, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8312231

RESUMO

Transgenic mice constitutively expressing IL-7 developed severe dermatitis with erythroderma and alopecia. The skin lesions were characterized by massive infiltration of mononuclear cells. Immunofluorescence staining showed that most of the infiltrating cells were T cells with the majority bearing the gamma delta TCR other than the V gamma 5 moiety. Furthermore, the number of gamma delta T cells had increased in the lymphoid organs of the dermatitis animals. These findings indicate the strong relationship between the expression of IL-7 and the development of gamma delta T cells in vivo and the pathological involvement of proliferated and/or activated gamma delta T cells in skin disease.


Assuntos
Dermatite/imunologia , Interleucina-7/fisiologia , Receptores de Antígenos de Linfócitos T gama-delta/análise , Linfócitos T/fisiologia , Animais , Anticorpos Monoclonais , Sequência de Bases , Movimento Celular , Dermatite/patologia , Citometria de Fluxo , Imuno-Histoquímica , Interleucina-7/biossíntese , Interleucina-7/sangue , Ativação Linfocitária , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular
6.
Thymus ; 21(3): 159-75, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-8236375

RESUMO

The present study investigates the capacity of the MRL104.8a thymic stromal cell clone to modulate T-cell growth. The culture supernatant (SN) from the MRL104.8a stromal cell monolayer was added to cultures of Th-clones with or without T-cell receptor (TCR) stimulation as provided by antigen (Ag) plus splenic antigen-presenting cells (APC). The results demonstrated that the MRL104.8a SN containing IL-7 activity induced dose-dependent proliferation of Th cells when they were not stimulated with Ag/APC. In contrast, addition of the same SN to cultures of Th cells during stimulation with Ag/APC resulted in potent dose-dependent inhibition of their proliferation. IL-7 contained in the SN was neither responsible for, nor involved in the inhibition event, because the inhibition was not observed with rIL-7 and was not neutralized by anti-IL-7 antibody. The growth inhibition of the Th clone in the presence of Ag plus APC was also induced by IL-10 or TGF-beta. However, the MRL104.8a SN-induced growth inhibition was mediated by a factor distinct from these cytokines, because (1) IL-10 cDNA was not amplified in polymerase chain reaction (PCR) products derived from MRL104.8a cells; (2) TGF-beta cDNA was detected in the PCR products, but only marginal levels of TGF-beta activity in an active form were found in the MRL104.8a SN and the SN-induced inhibition was not prevented by anti-TGF-beta antibody; and (3) addition of rIL-7 to antigen-stimulated cultures containing rTGF-beta or rIL-10 induced IL-7 mediated Th proliferation, whereas the MRL104.8a SN-induced inhibition was still observed in the presence of excess rIL-7. Moreover, this factor, designated thymic stroma-derived T-cell inhibitory factor, was found to have a m.w. of 20-25 x 10(3) and to exhibit heparin-binding property. Thus, these results indicate that the MRL104.8a thymic stromal cell clone produces a potentially novel factor that induces inhibition of antigen-stimulated T-cell proliferation.


Assuntos
Inibidores do Crescimento , Ativação Linfocitária/efeitos dos fármacos , Linfocinas/farmacologia , Timo/citologia , Animais , Antígenos/imunologia , Células Clonais , Citocinas/farmacologia , Heparina/metabolismo , Técnicas In Vitro , Interleucina-7/antagonistas & inibidores , Camundongos , Peso Molecular , Linfócitos T Auxiliares-Indutores/imunologia
7.
Proc Natl Acad Sci U S A ; 86(10): 3773-7, 1989 May.
Artigo em Inglês | MEDLINE | ID: mdl-2524833

RESUMO

A thymic stromal cell clone, MRL104.8a, expresses class I as well as class II H-2k antigens after exposure to gamma-interferon. This clone also produces thymic stroma-derived T-cell growth factor (TSTGF), which is distinct from other known interleukins and is capable of promoting the growth of various antigen-specific helper T cell (Th) clones without requiring a specific antigen or interleukin 2. When the keyhole limpet hemocyanin (KLH)-specific, I-Ek-restricted Th clone 9-16 was cultured on an Ia (I-Ak and I-Ek)-expressing MRL104.8a monolayer, potent proliferation of the 9-16 cells was induced by TSTGF produced by the monolayer. In contrast, the addition of KLH resulted in lethal growth inhibition of Th clone 9-16 cells. Another Th clone that is KLH-specific but I-Ab-restricted was capable of proliferating on the Iak-expressing MRL104.8a monolayer whether or not KLH was present. More importantly, death of Th clone 9-16 cells cultured on a MRL104.8a monolayer in the presence of KLH was almost completely prevented by the addition of anti-I-Ek or anti-CD3 monoclonal antibodies, which are capable of blocking antigen recognition by the T-cell receptor. However, when Th clone 9-16 cells were cultured in the presence of KLH but on a monolayer of MRL28.8a cells, another thymic stromal clone that expresses a comparable amount of I-Ek antigen but produces a marginal amount of TSTGF, cells did not die; a lethal effect was induced by adding TSTGF. These results indicate that the TSTGF-producing and Ia-expressing thymic stromal cells induce the continuous proliferation or selective elimination of each T-cell clone, depending on whether the T-cell receptor is stimulated by the relevant antigen associated with Ia molecules expressed on the stromal cell surface.


Assuntos
Antígenos de Histocompatibilidade Classe II/fisiologia , Receptores de Antígenos de Linfócitos T/fisiologia , Timo/citologia , Animais , Anticorpos Monoclonais/farmacologia , Divisão Celular , Células Cultivadas , Células Clonais , Substâncias de Crescimento/fisiologia , Técnicas In Vitro , Camundongos , Modelos Biológicos , Linfócitos T Auxiliares-Indutores/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...