| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Interferon gamma is a key cytokine in lung phase immunity to schistosomes but what is its precise role?
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| Autores: |
Wilson,R.A.
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| Data: |
1998-01-01
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| Ano: |
1998
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| Palavras-chave: |
Interferon gamma
Schistosoma mansoni
Lung phase immunity
Nitric oxide
Adhesion molecule
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| Resumo: |
Vaccination of mice with radiation-attenuated cercariae of Schistosoma mansoni induces a high level of protection against challenge with normal larvae. The immune effector mechanism, which operates in the lungs, is a cell-mediated delayed-type hypersensitivity response and involves the formation of a tight focus of mononuclear cells around embolised larvae. CD4+ T cells with Th1 characteristics are a major component of the infiltrate. They secrete abundant interferon gamma (IFN<FONT FACE="Symbol">g</font>) upon antigen stimulation in vitro, whilst in vivo neutralisation of the cytokine results in 90% abrogation of immunity. IFN<FONT FACE="Symbol">g</font> can induce a large number of genes and an attempt has been made to identify the ones which are essential components of the effector mechanism. Inducible nitric oxide synthase (iNOS) is such a candidate and nitric oxide (NO) is produced by cultures of airway leucocytes from the lungs of vaccinated mice post-challenge. However, the continued resistance of mice with a disrupted iNOS gene indicates that NO has only a minor role in the protective response. Mice with a disrupted IFN<FONT FACE="Symbol">g</font> receptor gene have been used to dissect the role of the cytokine. After vaccination and challenge, CD4+ T cells from the pulmonary interstitium have reduced levels of ICAM-1 and LFA-1 expression, compared to wild-type animals, which coincides with a reduced cohesiveness of foci. However, immunity is not significantly impaired in mice with a disrupted ICAM-1 gene, and focus formation is normal. Similarly, a role has not been found for CD2/CD48 interactions in cell aggregation. Possible IFN<FONT FACE="Symbol">g</font>-inducible molecules yet to be fully investigated include other ligand-receptor pairs, chemokines, and tumour necrosis factor <FONT FACE="Symbol">a</font>.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000100022
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X1998000100022
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.31 n.1 1998
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| Direitos: |
info:eu-repo/semantics/openAccess
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