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Defective adhesion in tumor infiltrating CD8+ T cells.
Koneru, Mythili; Monu, Ngozi; Schaer, David; Barletta, Justine; Frey, Alan B.
Afiliação
  • Koneru M; Department of Cell Biology, and Kaplan Cancer Center, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
J Immunol ; 176(10): 6103-11, 2006 May 15.
Article em En | MEDLINE | ID: mdl-16670319
CD8(+) tumor-infiltrating lymphocytes (TIL) are defective in cytolysis due to tumor-induced inhibition of proximal TCR-mediated signaling, a defect that is relieved upon purification and brief culture. We show in this study that frequency of conjugation in vitro of nonlytic TIL with tumor cells is low in comparison with their lytic counterparts, and the strength of interaction and duration of conjugation are also reduced. Previous reports show that p56(lck) activation is required for TCR-initiated LFA-1 avidity up-regulation, raising the question: is low LFA-1 avidity the basis of reduced TIL conjugation frequency? When stimulated with phorbol ester, nonlytic TIL bind purified ICAM-1 equivalently as lytic TIL, suggesting that LFA-1 can be activated if proximal TCR signaling is bypassed. However, when treated with phorbol ester, the conjugation frequency of nonlytic TIL does not increase. CD2 and CD8 also mediate T cell adhesion to cognate target cells and are both expressed at lower levels in nonlytic TIL in addition to being excluded from the immune synapse formed upon conjugation. Collectively, these results imply that adhesion defects in nonlytic TIL result from a combination of decreased cell surface levels of adhesion molecules, deficient LFA-1 activation, and the failure to recruit essential adhesion receptors to the membrane contact site formed with cognate target cells.
Assuntos
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Base de dados: MEDLINE Assunto principal: Linfócitos do Interstício Tumoral / Linfócitos T CD8-Positivos Limite: Animals Idioma: En Revista: J Immunol Ano de publicação: 2006 Tipo de documento: Article País de afiliação: Estados Unidos
Buscar no Google
Base de dados: MEDLINE Assunto principal: Linfócitos do Interstício Tumoral / Linfócitos T CD8-Positivos Limite: Animals Idioma: En Revista: J Immunol Ano de publicação: 2006 Tipo de documento: Article País de afiliação: Estados Unidos