Requirements for Vav guanine nucleotide exchange factors and Rho GTPases in FcgammaR- and complement-mediated phagocytosis.
Immunity
; 24(3): 305-16, 2006 Mar.
Article
en En
| MEDLINE
| ID: mdl-16546099
Vav guanine nucleotide exchange factors (GEFs) have been implicated in cell adhesion by integrin and immune response receptors through the regulation of Rho GTPases. Here, we examine the role of Vav and Rho GTPases in phagocytosis by using primary murine macrophages. The genetic deletion of Rac1 and Rac2 prevents phagocytosis mediated by integrin and Fcgamma receptors (FcgammaR), whereas the genetic deletion of Vav1 and Vav3 only prevents integrin-mediated phagocytosis through the complement receptor alpha(M)beta(2). In addition, a Rac1/2 or Vav1/3 deficiency blocks Arp2/3 recruitment and actin polymerization at the complement-induced phagosome, indicating that these proteins regulate early steps in phagocytosis. Moreover, constitutively active Rac is able to rescue actin polymerization and complement-mediated phagocytosis in Vav-deficient macrophages. These studies indicate that Rac is critical for complement- and FcgammaR-mediated phagocytosis. In contrast, Vav is specifically required for complement-mediated phagocytosis, suggesting that Rac is regulated by GEFs other than Vav downstream of the FcgammaR.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fagocitosis
/
Antígeno de Macrófago-1
/
Receptores de IgG
/
Proteínas de Unión al GTP rho
/
Factores de Intercambio de Guanina Nucleótido
/
Proteínas Proto-Oncogénicas c-vav
Límite:
Animals
Idioma:
En
Revista:
Immunity
Asunto de la revista:
ALERGIA E IMUNOLOGIA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos