%0 Journal Article %T IL4I1: an inhibitor of the CD8(+) antitumor T-cell response in vivo. %T IL4I1 and tumor immunoresistance %+ Institut Mondor de Recherche Biomédicale (IMRB) %+ Institut Cochin (IC UM3 (UMR 8104 / U1016)) %+ Service d'Anatomo-Pathologie %+ Service d'immunologie biologique %A Lasoudris, Fanette %A Cousin, Céline %A Prevost-Blondel, Armelle %A Martin-Garcia, Nadine %A Abd-Alsamad, Issam %A Ortonne, Nicolas %A Farcet, Jean-Pierre %A Castellano, Flavia %A Molinier-Frenkel, Valérie %Z Grants support: ARC subvention fixe 4883 (FC) and the French association for therapeutic, genetic and immunologic research on lymphoma (ARTGIL) granted by Roche and Amgen (CC). %< avec comité de lecture %@ 0014-2980 %J European Journal of Immunology %I Wiley-VCH Verlag %V 41 %N 6 %P 1629-38 %8 2011-06 %D 2011 %R 10.1002/eji.201041119 %M 21469114 %K IL4I1 %K tumor escape %K mice %K immunoediting %K phenylalanine oxidase %Z Life Sciences [q-bio]/Biochemistry, Molecular BiologyJournal articles %X The L-phenylalanine oxidase IL4I1 inhibits T-cell proliferation in vitro through H(2) O(2) production, and is highly expressed in tumor-associated macrophages. IL4I1 is also detected by immunohistochemistry in neoplastic cells from several B-cell lymphomas and some non-lymphoid tumors. To evaluate IL4I1's effect on tumor growth, we developed a mouse melanoma model constitutively coexpressing IL4I1 and the GP33 epitope. After GP33 vaccination, tumors developed more frequently in mice injected with IL4I1-expressing cells in comparison with mice receiving control cells. Tumor escape was preceded by a rapid diminution of IFN-γ-producing cytotoxic antitumor CD8(+) T cells. Moreover, tumor incidence was already increased when only 20% of the injected cells expressed IL4I1. The minimal IL4I1 activities leading to tumor escape were close to those detected in human melanoma and mesothelioma. Thus, we demonstrate the immunosuppressive functions of IL4I1 in vivo and suggest that IL4I1 facilitates human tumor growth by inhibiting the CD8(+) antitumor T-cell response. %G English %2 https://inserm.hal.science/inserm-00604898/document %2 https://inserm.hal.science/inserm-00604898/file/Figures-eji-HAL.pdf %2 https://inserm.hal.science/inserm-00604898/file/HAL-INSERM280611.pdf %2 https://inserm.hal.science/inserm-00604898/file/inserm-00604898_edited.pdf %L inserm-00604898 %U https://inserm.hal.science/inserm-00604898 %~ INSERM %~ UNIV-PARIS5 %~ CNRS %~ APHP %~ IMRB %~ UPEC %~ UNIV-PARIS %~ UP-SANTE