RESUMEN
In mice, γδ-T lymphocytes that express the co-stimulatory molecule, CD27, are committed to the IFNγ-producing lineage during thymic development. In the periphery, these cells play a critical role in host defense and anti-tumor immunity. Unlike αß-T cells that rely on MHC-presented peptides to drive their terminal differentiation, it is unclear whether MHC-unrestricted γδ-T cells undergo further functional maturation after exiting the thymus. Here, we provide evidence of phenotypic and functional diversity within peripheral IFNγ-producing γδ T cells. We found that CD27+ Ly6C- cells convert into CD27+Ly6C+ cells, and these CD27+Ly6C+ cells control cancer progression in mice, while the CD27+Ly6C- cells cannot. The gene signatures of these two subsets were highly analogous to human immature and mature γδ-T cells, indicative of conservation across species. We show that IL-27 supports the cytotoxic phenotype and function of mouse CD27+Ly6C+ cells and human Vδ2+ cells, while IL-27 is dispensable for mouse CD27+Ly6C- cell and human Vδ1+ cell functions. These data reveal increased complexity within IFNγ-producing γδ-T cells, comprising immature and terminally differentiated subsets, that offer new insights into unconventional T-cell biology.
Asunto(s)
Antígenos Ly , Receptores de Antígenos de Linfocitos T gamma-delta , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral , Animales , Ratones , Antígenos Ly/metabolismo , Antígenos Ly/genética , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/genética , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/inmunología , Humanos , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Interferón gamma/metabolismo , Interferón gamma/inmunología , Interleucina-27/metabolismo , Interleucina-27/genética , Diferenciación Celular/inmunología , Ratones Endogámicos C57BL , Linfocitos T Citotóxicos/inmunología , Linfocitos T Citotóxicos/metabolismoRESUMEN
The contribution of γδ T cells to immune responses is associated with rapid secretion of interferon-γ (IFN-γ). Here, we show a perinatal thymic wave of innate IFN-γ-producing γδ T cells that express CD8αß heterodimers and expand in preclinical models of infection and cancer. Optimal CD8αß+ γδ T cell development is directed by low T cell receptor signaling and through provision of interleukin (IL)-4 and IL-7. This population is pathologically relevant as overactive, or constitutive, IL-7R-STAT5B signaling promotes a supraphysiological accumulation of CD8αß+ γδ T cells in the thymus and peripheral lymphoid organs in two mouse models of T cell neoplasia. Likewise, CD8αß+ γδ T cells define a distinct subset of human T cell acute lymphoblastic leukemia pediatric patients. This work characterizes the normal and malignant development of CD8αß+ γδ T cells that are enriched in early life and contribute to innate IFN-γ responses to infection and cancer.
Asunto(s)
Inmunidad Innata , Interferón gamma , Receptores de Antígenos de Linfocitos T gamma-delta , Receptores de Interleucina-7 , Factor de Transcripción STAT5 , Timo , Animales , Interferón gamma/metabolismo , Interferón gamma/inmunología , Ratones , Humanos , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Timo/inmunología , Receptores de Interleucina-7/metabolismo , Factor de Transcripción STAT5/metabolismo , Transducción de Señal/inmunología , Ratones Endogámicos C57BL , Linfocitos T CD8-positivos/inmunología , Ratones Noqueados , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Antígenos CD8/metabolismo , Femenino , Linfocitos Intraepiteliales/inmunología , Linfocitos Intraepiteliales/metabolismo , Interleucina-7/metabolismoRESUMEN
Intraepithelial lymphocytes (IEL) expressing γδ T-cell receptors (γδTCR) play key roles in elimination of colon cancer. However, the precise mechanisms by which progressing cancer cells evade immunosurveillance by these innate T cells are unknown. Here, we investigated how loss of the Apc tumor suppressor in gut tissue could enable nascent cancer cells to escape immunosurveillance by cytotoxic γδIELs. In contrast with healthy intestinal or colonic tissue, we found that γδIELs were largely absent from the microenvironment of both mouse and human tumors, and that butyrophilin-like (BTNL) molecules, which can critically regulate γδIEL through direct γδTCR interactions, were also downregulated in tumors. We then demonstrated that ß-catenin activation through loss of Apc rapidly suppressed expression of the mRNA encoding the HNF4A and HNF4G transcription factors, preventing their binding to promoter regions of Btnl genes. Reexpression of BTNL1 and BTNL6 in cancer cells increased γδIEL survival and activation in coculture assays but failed to augment their cancer-killing ability in vitro or their recruitment to orthotopic tumors. However, inhibition of ß-catenin signaling via genetic deletion of Bcl9/Bcl9L in either Apc-deficient or mutant ß-catenin mouse models restored Hnf4a, Hnf4g, and Btnl gene expression and γδ T-cell infiltration into tumors. These observations highlight an immune-evasion mechanism specific to WNT-driven colon cancer cells that disrupts γδIEL immunosurveillance and furthers cancer progression.
Asunto(s)
Neoplasias del Colon , Linfocitos Intraepiteliales , Ratones , Animales , Humanos , beta Catenina/genética , beta Catenina/metabolismo , Linfocitos Intraepiteliales/metabolismo , Butirofilinas/genética , Butirofilinas/metabolismo , Neoplasias del Colon/genética , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Microambiente TumoralRESUMEN
IL-17A-producing γδ T cells in mice consist primarily of Vγ6+ tissue-resident cells and Vγ4+ circulating cells. How these γδ T cell subsets are regulated during homeostasis and cancer remains poorly understood. Using single-cell RNA sequencing and flow cytommetry, we show that lung Vγ4+ and Vγ6+ cells from tumor-free and tumor-bearing mice express contrasting cell surface molecules as well as distinct co-inhibitory molecules, which function to suppress their expansion. Vγ6+ cells express constitutively high levels of PD-1, whereas Vγ4+ cells upregulate TIM-3 in response to tumor-derived IL-1ß and IL-23. Inhibition of either PD-1 or TIM-3 in mammary tumor-bearing mice increased Vγ6+ and Vγ4+ cell numbers, respectively. We found that genetic deletion of γδ T cells elicits responsiveness to anti-PD-1 and anti-TIM-3 immunotherapy in a mammary tumor model that is refractory to T cell checkpoint inhibitors, indicating that IL-17A-producing γδ T cells instigate resistance to immunotherapy. Together, these data demonstrate how lung IL-17A-producing γδ T cell subsets are differentially controlled by PD-1 and TIM-3 in steady-state and cancer.
Asunto(s)
Receptor 2 Celular del Virus de la Hepatitis A , Interleucina-17 , Neoplasias , Receptor de Muerte Celular Programada 1 , Subgrupos de Linfocitos T , Animales , Ratones , Receptor de Muerte Celular Programada 1/metabolismo , Receptor 2 Celular del Virus de la Hepatitis A/metabolismoRESUMEN
γδT cells are unconventional T cells particularly abundant in mucosal tissues that play an important role in tissue surveillance, homeostasis, and cancer. γδT cells recognize stressed cells or cancer cells through the NKG2D receptor to kill these cells and maintain normality. Contrary to the well-established anti-tumor function of these NKG2D-expressing γδT cells, we show here that, in mice, NKG2D regulates a population of pro-tumor γδT cells capable of producing IL-17A. Germline deletion of Klrk1, the gene encoding NKG2D, reduced the frequency of γδT cells in the tumor microenvironment and delayed tumor progression. We further show that blocking NKG2D reduced the capability of γδT cells to produce IL-17A in the pre-metastatic lung and that co-culture of lung T cells with NKG2D ligand-expressing tumor cells specifically increased the frequency of γδT cells. Together, these data support the hypothesis that, in a tumor microenvironment where NKG2D ligands are constitutively expressed, γδT cells accumulate in an NKG2D-dependent manner and drive tumor progression by secreting pro-inflammatory cytokines, such as IL-17A.
RESUMEN
Unconventional T cells and their involvement in cancer are understudied in comparison to conventional T cells, but recent findings indicate that these cells play important roles in both cancer progression and inhibition. Here, we briefly review the dichotomous role of three unconventional T cell lineages: γδ T cells, MAIT cells and NKT cells. Studies using mouse models of cancer show how this unconventional trilogy interacts with cancer epithelial cells and other immune cell populations during tumour evolution. These reports highlight various potential avenues for therapeutic intervention that may be exploited for cancer immunotherapy.
Asunto(s)
Células T Invariantes Asociadas a Mucosa , Células T Asesinas Naturales , Neoplasias , Animales , Linaje de la Célula , Inmunoterapia , Ratones , Neoplasias/terapiaRESUMEN
Current nutritional recommendations are focused on energy, fat, carbohydrate, protein and vitamins. Less attention has been paid to the nutritional demand of one-carbon units for nucleotide and methionine synthesis. Here, we investigated the impact of sodium formate supplementation as a nutritional intervention to increase the dietary intake of one-carbon units. A cohort of six female and six male mice received 125 mM of sodium formate in the drinking water for three months. A control group of another six female and six male mice was also followed up for the same period of time. Tail vein blood samples were collected once a month and profiled with a haematology analyser. At the end of the study, blood and tissues were collected for metabolomics analysis and immune cell profiling. Formate supplementation had no significant physiological effect on male mice, except for a small decrease in body weight. Formate supplementation had no significant effect on the immune cell counts during the intervention or at the end of the study in either gender. In female mice, however, the body weight and spleen wet weight were significantly increased by formate supplementation, while the blood plasma levels of amino acids were decreased. Formate supplementation also increased the frequency of bifidobacteria, a probiotic bacterium, in the stools of female mice. We conclude that formate supplementation induces physiological changes in a gender-specific manner.
Asunto(s)
Aminoácidos/sangre , Peso Corporal/efectos de los fármacos , Suplementos Dietéticos , Formiatos/farmacología , Animales , Bifidobacterium/efectos de los fármacos , Bifidobacterium/metabolismo , Femenino , Formiatos/sangre , Microbioma Gastrointestinal , Sistema Inmunológico/metabolismo , Masculino , Ratones , Filogenia , Tamaño de la MuestraRESUMEN
MYC is implicated in the development and progression of pancreatic cancer, yet the precise level of MYC deregulation required to contribute to tumor development has been difficult to define. We used modestly elevated expression of human MYC, driven from the Rosa26 locus, to investigate the pancreatic phenotypes arising in mice from an approximation of MYC trisomy. We show that this level of MYC alone suffices to drive pancreatic neuroendocrine tumors, and to accelerate progression of KRAS-initiated precursor lesions to metastatic pancreatic ductal adenocarcinoma (PDAC). Our phenotype exposed suppression of the type I interferon (IFN) pathway by the combined actions of MYC and KRAS, and we present evidence of repressive MYC-MIZ1 complexes binding directly to the promoters of the genes encodiing the type I IFN regulators IRF5, IRF7, STAT1, and STAT2. Derepression of IFN regulator genes allows pancreatic tumor infiltration by B and natural killer (NK) cells, resulting in increased survival. SIGNIFICANCE: We define herein a novel mechanism of evasion of NK cell-mediated immunity through the combined actions of endogenously expressed mutant KRAS and modestly deregulated expression of MYC, via suppression of the type I IFN pathway. Restoration of IFN signaling may improve outcomes for patients with PDAC.This article is highlighted in the In This Issue feature, p. 747.