title: The Wiskott-Aldrich syndrome protein regulates CTL cytotoxicity and is required for efficient killing of B cell lymphoma targets.
abstract: WAS is a primary immunodeficiency as a result of mutations in the gene encoding the WASP, a key actin regulator of hematopoietic cells. Whether killing defects in CD8(+) CTLs contribute to WAS-associated immunodeficiency and susceptibility to tumor development remains to be explored. CTL lines from WAS patients, generated by repeated stimulation with SAg-loaded B-EBV, displayed reduced production of cytokines (IL-2, IFN-γ, and TNF-α) but almost normal proliferation upon SAg stimulation. Although WAS CTLs killed target B cells in a SAg dose-dependent manner, their efficiency was reduced, especially at a low SAg dose. The cytotoxic efficiency of WAS CTLs was particularly reduced against tumoral B cell lines. WAS CTLs expressed normal levels of lytic molecules and demonstrated efficient exocytosis upon target cell encounter. However, the lytic granules appeared not to fully polarize toward the center of the CTL/tumor target cell contact area. Importantly, the use of a gene therapy lentiviral vector was sufficient to restore efficient cytotoxic activity. Our study suggests that CTL dysfunction contributes to the development of hematological malignancies in WAS patients.
authors.affiliation: INSERM U563, and Université Toulouse III Paul-Sabatier, Purpan University Hospital, Toulouse, France.
authors.forename: Julie
authors.initials: J
authors.lastname: De Meester
authors.forename: Ronan
authors.initials: R
authors.lastname: Calvez
authors.forename: Salvatore
authors.initials: S
authors.lastname: Valitutti
authors.forename: Loïc
authors.initials: L
authors.lastname: Dupré
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D002051:Burkitt Lymphoma / Q000235:genetics / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002460:Cell Line; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D015536:Down-Regulation; D005434:Flow Cytometry; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000276:immunology; D018613:Microscopy, Confocal; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology; D014923:Wiskott-Aldrich Syndrome / Q000235:genetics / Q000276:immunology; D051316:Wiskott-Aldrich Syndrome Protein / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology
chemical_list: D016207:Cytokines; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D014409:Tumor Necrosis Factor-alpha; D051316:Wiskott-Aldrich Syndrome Protein