ARTÍCULO

Inhibition of FOXP3/NFAT interaction enhances T cell function after TCR stimulation

Autores: Lozano Moreda, Teresa; Villanueva Legarda, Lorea; Durántez Delgado, María del Carmen; Gorraiz Ayala, Marta; Ruiz Egozcue, Marta; Belsúe Urquizu, Virginia; Riezu Boj, José Ignacio; Hervas Stubbs, Sandra; Oyarzabal Santamarina, Julen; Bandukwala, H.; Lourenço, A. R.; Coffer, P. J.; Sarobe Ugarriza, Pablo; Prieto Valtueña, Jesús María; Casares Lagar, Noelia; Lasarte Sagastibelza, Juan José
Título de la revista: JOURNAL OF IMMUNOLOGY
ISSN: 0022-1767
Volumen: 195
Número: 7
Páginas: 3180 - 3189
Fecha de publicación: 2015
Resumen:
Regulatory T cell (Treg) activity is modulated by a cooperative complex between the transcription factor NFAT and FOXP3, a lineage specification factor for Tregs. FOXP3/NFAT interaction is required to repress expression of IL-2, upregulate expression of the Treg markers CTLA4 and CD25, and confer suppressor function to Tregs. However, FOXP3 is expressed transiently in conventional CD4+ T cells upon TCR stimulation and may lead to T cell hyporesponsiveness. We found that a short synthetic peptide able to inhibit FOXP3/NFAT interaction impaired suppressor activity of conventional Tregs in vitro. Specific inhibition of FOXP3/NFAT interaction with this inhibitory peptide revealed that FOXP3 downregulates NFAT-driven promoter activity of CD40L and IL-17. Inhibition of FOXP3/NFAT interaction upregulated CD40L expression on effector T cells and enhanced T cell proliferation and IL-2, IFN-¿, IL-6, or IL-17 production in response to TCR stimulation. The inhibitory peptide impaired effector T cell conversion into induced Tregs in the presence of TGF-ß. Moreover, in vivo peptide administration showed antitumor efficacy in mice bearing Hepa129 or TC1 tumor cells when combined with sorafenib or with an antitumor vaccine, respectively. Our results suggest that inhibition of NFAT/FOXP3 interaction might improve antitumor immunotherapies.