TGF-β2 induces Grb2 to recruit PI3-K to TGF-RII that activates JNK/AP-1-signaling and augments invasiveness of Theileria-transformed macrophages.
Theileria-infected macrophages display many features of cancer cells such as heightened invasive capacity; however, the tumor-like phenotype is reversible by killing the parasite. Moreover, virulent macrophages can be attenuated by multiple in vitro passages and so provide a powerful model to elucidate mechanisms related to transformed macrophage virulence. Here, we demonstrate that in two independent Theileria-transformed macrophage cell lines Grb2 expression is down-regulated concomitant with loss of tumor virulence. Using peptidimer-c to ablate SH2 and SH3 interactions of Grb2 we identify TGF-receptor II and the p85 subunit of PI3-K, as Grb2 partners in virulent macrophages. Ablation of Grb2 interactions reduces PI3-K recruitment to TGF-RII and decreases PIP3 production, and dampens JNK phosphorylation and AP-1-driven transcriptional activity down to levels characteristic of attenuated macrophages. Loss of TGF-R>PI3-K>JNK>AP-1 signaling negatively impacts on virulence traits such as reduced JAM-L/ITG4A and Fos-B/MMP9 expression that contribute to virulent macrophage adhesion and invasiveness.
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, France.|Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014 France.
Malak
M
Haidar
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, France.|Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014 France.
Jessie
J
Whitworth
UF Pharmacocinétique et pharmacochimie Hôpital Cochin, Paris, France Assistance Publique Hôpitaux de Paris.|UMR8638 CNRS, Faculté de Pharmacie, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, France.
Gaelle
G
Noé
UF Pharmacocinétique et pharmacochimie Hôpital Cochin, Paris, France Assistance Publique Hôpitaux de Paris.|UMR8638 CNRS, Faculté de Pharmacie, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, France.
Wang Qing
WQ
Liu
UF Pharmacocinétique et pharmacochimie Hôpital Cochin, Paris, France Assistance Publique Hôpitaux de Paris.|UMR8638 CNRS, Faculté de Pharmacie, Université Paris Descartes, PRES Sorbonne Paris Cité, Paris, France.
Michel
M
Vidal
Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Faculté de Médicine, Université Paris Descartes - Sorbonne Paris Cité, France.|Inserm U1016, Cnrs UMR8104, Cochin Institute, Paris, 75014 France.
Gordon
G
Langsley
D002461:Cell Line, Transformed; D051380:GRB2 Adaptor Protein / Q000378:metabolism*; D006801:Humans; D020935:MAP Kinase Signaling System; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism*; D016794:Theileria; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D053781:Transforming Growth Factor beta2 / Q000378:metabolism*
D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D018125:Receptors, Transforming Growth Factor beta; C509041:TGFB2 protein, human; D018808:Transcription Factor AP-1; D053781:Transforming Growth Factor beta2; D019869:Phosphatidylinositol 3-Kinases