title: T helper type 17 cells contribute to anti-tumour immunity and promote the recruitment of T helper type 1 cells to the tumour.
abstract: T helper type 17 (Th17) lymphocytes are found in high frequency in tumour-burdened animals and cancer patients. These lymphocytes, characterized by the production of interleukin-17 and other pro-inflammatory cytokines, have a well-defined role in the development of inflammatory and autoimmune pathologies; however, their function in tumour immunity is less clear. We explored possible opposing anti-tumour and tumour-promoting functions of Th17 cells by evaluating tumour growth and the ability to promote tumour infiltration of myeloid-derived suppressor cells (MDSC), regulatory T cells and CD4(+)  interferon-γ(+) cells in a retinoic acid-like orphan receptor γt (RORγt) -deficient mouse model. A reduced percentage of Th17 cells in the tumour microenvironment in RORγt-deficient mice led to enhanced tumour growth, that could be reverted by adoptive transfer of Th17 cells. Differences in tumour growth were not associated with changes in the accumulation or suppressive function of MDSC and regulatory T cells but were related to a decrease in the proportion of CD4(+) T cells in the tumour. Our results suggest that Th17 cells do not affect the recruitment of immunosuppressive populations but favour the recruitment of effector Th1 cells to the tumour, thereby promoting anti-tumour responses.
authors.affiliation: Departamento de Biologia, Facultad de Ciencias, Universidad de Chile, Santiago, Chile.
authors.forename: Sarah
authors.initials: S
authors.lastname: Nuñez
authors.forename: Juan Jose
authors.initials: JJ
authors.lastname: Saez
authors.forename: Dominique
authors.initials: D
authors.lastname: Fernandez
authors.forename: Felipe
authors.initials: F
authors.lastname: Flores-Santibañez
authors.forename: Karla
authors.initials: K
authors.lastname: Alvarez
authors.forename: Gabriela
authors.initials: G
authors.lastname: Tejon
authors.forename: Paulina
authors.initials: P
authors.lastname: Ruiz
authors.forename: Paula
authors.initials: P
authors.lastname: Maldonado
authors.forename: Yessia
authors.initials: Y
authors.lastname: Hidalgo
authors.forename: Valeria
authors.initials: V
authors.lastname: Manriquez
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Bono
authors.forename: Mario
authors.initials: M
authors.lastname: Rosemblatt
authors.forename: Daniela
authors.initials: D
authors.lastname: Sauma
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D007108:Immune Tolerance; D051379:Mice; D008817:Mice, Mutant Strains; D009369:Neoplasms / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3 / Q000235:genetics / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology* / Q000473:pathology; D058504:Th17 Cells / Q000276:immunology* / Q000473:pathology
chemical_list: D057132:Nuclear Receptor Subfamily 1, Group F, Member 3