PI3Kgamma is the dominant isoform involved in migratory responses of human T lymphocytes: effects of ex vivo maintenance and limitations of non-viral delivery of siRNA.
Cell Signal
; 19(12): 2528-39, 2007 Dec.
Article
em En
| MEDLINE
| ID: mdl-17900864
ABSTRACT
Use of mice in which individual PI3K isoforms have been deleted or mutated by gene targeting, has determined that PI3Kgamma provides a key migratory signal for T lymphocyte migration. Since PI3Kgamma can be a dispensable signal for directional migration of human T cells, we have adopted a pharmacological and siRNA strategy to assess the contribution of individual PI3K isoforms to chemokine-stimulated migration of human T cells. The broad spectrum PI3K isoform inhibitor Ly294002 inhibits CXCL12-stimulated migration of freshly isolated T lymphocytes. Use of second generation inhibitors that can discriminate between individual PI3K isoforms, revealed that PI3Kgamma was the major contributor to CXCL12-induced migration and PI3K/Akt signaling (as assessed by S6 phosphorylation). Non-viral delivery of siRNA targeting class I (PI3Kgamma), class II (PI3KC2alpha and PI3KC2beta) and class III PI3Ks, followed by 3 days ex vivo culture, reduces the levels of isoform mRNA, but is insufficient to impact on cell migration responses. However, ex vivo maintenance of T cells alone, independently of siRNA treatment, resulted in the migratory response of T cells toward CXCL12 becoming insensitive to Ly294002. Remarkably, random migration remains sensitive to Ly294002. This study therefore, highlights that the migratory response of freshly isolated human T cells is dependent on PI3K signals that are provided predominantly by PI3Kgamma. However, the role of PI3K in cell migration is context-dependent and diminishes during ex vivo maintenance.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Linfócitos T
/
Transfecção
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Quimiotaxia de Leucócito
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Técnicas de Cultura de Células
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Fosfatidilinositol 3-Quinases
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RNA Interferente Pequeno
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Interferência de RNA
Limite:
Humans
Idioma:
En
Revista:
Cell Signal
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Reino Unido