title: The protooncogene Vav1 regulates murine leukemia virus-induced T-cell leukemogenesis.
abstract: Vav1 is expressed exclusively in hematopoietic cells and is required for T cell development and activation. Vav1-deficient mice show thymic hypocellularity due to a partial block during thymocyte development at the DN3 stage and between the double positive (DP) and single positive (SP) transition. Vav1 has been shown to play a significant role in several non-hematopoietic tumors but its role in leukemogenesis is unknown. To address this question, we investigated the role of Vav1 in retrovirus-induced T cell leukemogenesis. Infection of Vav1-deficient mice with the Moloney strain of murine leukemia virus (M-MuLV) significantly affected tumor phenotype without modulating tumor incidence or latency. M-MuLV-infected Vav1-deficient mice showed reduced splenomegaly, higher hematocrit levels and hypertrophic thymi. Notably, Vav1-deficient mice with M-MuLV leukemias presented with markedly lower TCRβ/CD3 levels, indicating that transformation occurred at an earlier stage of T cell development than in WT mice. Thus, impaired T cell development modulates the outcome of retrovirus-induced T cell leukemias, demonstrating a link between T cell development and T cell leukemogenesis.
authors.affiliation: Institut de Génétique Moléculaire de Montpellier; UMR 5535; CNRS; Montpellier, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Kaminski
authors.forename: Oumeya
authors.initials: O
authors.lastname: Adjali
authors.forename: Chantal
authors.initials: C
authors.lastname: Jacquet
authors.forename: Johan
authors.initials: J
authors.lastname: Garaude
authors.forename: Anne
authors.initials: A
authors.lastname: Keriel
authors.forename: Adeline
authors.initials: A
authors.lastname: Lassaux
authors.forename: Robert
authors.initials: R
authors.lastname: Hipskind
authors.forename: Marc
authors.initials: M
authors.lastname: Sitbon
authors.forename: Naomi
authors.initials: N
authors.lastname: Taylor
authors.forename: Martin
authors.initials: M
authors.lastname: Villalba