Biology subjects

Kilbey, A.

Publications and source records attributed to Kilbey, A..

6 recordsLinked to original sources

bioRxiv2023

IL-27 maintains cytotoxic Ly6C+ gamma delta T cells that arise from immature precursors

In mice, {gamma}{delta} T cells that express the co-stimulatory molecule, CD27, are committed to the IFN{gamma}-producing lineage in the thymus, and in the periphery, these cells play a critical role in host defence and anti-tumor immunity. Unlike {beta} T cells that rely on MHC-presented peptides to drive their terminal differentiation, it is unclear whether MHC-unrestricted {gamma}{delta} T cells undergo further functional maturation after exiting the thymus. Here, we provide evidence of phenotypic and functional diversity within peripheral IFN{gamma}-producing {gamma}{delta} T cells. We found that immature CD27+Ly6C-- cells convert into mature CD27+Ly6C+ cells, and these mature cells control cancer progression while the immature cells cannot. The gene signatures of these two subsets were highly analogous to human immature and mature {gamma}{delta} 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 V{delta}2+ cells, while IL-27 is dispensable for mouse CD27+Ly6C-- cells and human V{delta}1+ cells. These data reveal increased complexity within IFN{gamma}-producing {gamma}{delta} T cells, comprising of immature and terminally differentiated subsets, that offer new insights into unconventional T cell biology.

immunology↗

bioRxiv2022

Specialized Tfh cell subsets driving type-1 and type-2 humoral responses in lymphoid tissue

Effective antibody responses are essential to generate protective humoral immunity. Different inflammatory signals polarize T cells towards an appropriate effector phenotype during an infection or immunization. Th1 and Th2 cells have been associated with the polarization of humoral responses for several decades. However, it is now established that T follicular helper cells (Tfh) have a unique ability to access the B cell follicle and support the Germinal Centre (GCs) responses by providing help to B cells. We investigated the specialization of Tfh cells induced under type-1 and type-2 conditions. We first studied homogenous Tfh cell populations generated by adoptively transferred TCR-transgenic T cells in mice immunized with type-1 and type-2 adjuvants. Using a machine learning approach, we established a gene expression signature that discriminates Tfh cells polarized towards type-1 and type-2 response, defined as Tfh1 and Tfh2 cells. The Tfh1 and Tfh2 distinct signature was validated against datasets of Tfh cells induced following LCMV or helminth infection. Using single-cell transcriptomics, we also dissected the heterogeneity of Tfh cells from the two immunizing conditions. Our results show that Tfh cells acquire a specialized function under distinct types of immune responses, but with the coexistence of a small population of Tfh cells of the alternative type. Furthermore, the specific molecular hallmarks of Tfh1 and Tfh2 cells identified herein offer putative new targets for tuning humoral responses.

immunology↗

bioRxiv2022

β-catenin obstructs γδ T cell immunosurveillance in colon cancer through loss of BTNL expression

WNT/{beta}-catenin signaling endows cancer cells with proliferative capacity and immune-evasive functions that impair anti-cancer immunosurveillance by conventional, cytoxtoic T cells. However, the impact of dysregulated WNT signalling on unconventional, tissue-resident T cells, specifically in colon cancer is unknown. Here, we show that cancer cells in Apc-mutant mouse models escape immunosurveillance from gut-resident intraepithelial lymphocytes (IELs) expressing {gamma}{delta} T cell receptors ({gamma}{delta}TCRs). Analysis of late-stage tumors from mice and humans revealed that {gamma}{delta}IELs are largely absent from the tumor microenvironment, and that butyrophilin-like (BTNL) molecules, which can critically regulate {gamma}{delta}IEL through direct {gamma}{delta}TCR-interactions, are also downregulated. We could attribute this to {beta}-catenin stabilization, which rapidly decreased expression of the transcription factors, HNF4A and HNF4G, that we found to bind promoter regions of Btnl genes, thereby driving their expression in normal gut epithelial cells. Indeed, inhibition of {beta}-catenin signaling restored Btnl1 gene expression and {gamma}{delta} T cell infiltration into tumors. These observations highlight an immune-evasion mechanism specific to WNT-driven colon cancer cells that disrupts {gamma}{delta}IEL immunosurveillance and furthers cancer progression.

cancer biology↗

bioRxiv2021

Single-cell analysis uncovers differential regulation of lung γδ T cell subsets by the co-inhibitory molecules, PD-1 and TIM-3

IL-17A-producing {gamma}{delta} T cells within the lung consist of both V{gamma}6+ tissue-resident cells and V{gamma}4+ circulating cells that play important roles in homeostasis, inflammation, infection, tumor progression and metastasis. How these {gamma}{delta} T cell subsets are regulated in the lung environment during homeostasis and cancer remains poorly understood. Using single-cell RNA sequencing and flow cytometry, we show that lung V{gamma}6+ cells express a repertoire of cell surface molecules distinctive from V{gamma}4+ cells, including PD-1 and ICOS. We found that PD-1 functions as a co-inhibitory molecule on V{gamma}6+ cells to reduce IL-17A production, whereas manipulation of ICOS signaling fails to affect IL-17A in V{gamma}6+ cells. In a mammary tumor model, ICOS and PD-1 expression on lung V{gamma}6+ cells remained stable. However, V{gamma}6+ and V{gamma}4+ cells within the lung pre-metastatic niche increased expression of IL-17A, IL-17F, amphiregulin (AREG) and TIM-3 in response to tumor-derived IL-1{beta} and IL-23, where the upregulation of TIM-3 was specific to V{gamma}4+ cells. Inhibition of either PD-1 or TIM-3 in mammary tumor-bearing mice further increased IL-17A by V{gamma}6+ and V{gamma}4+ cells, indicating that both PD-1 and TIM-3 function as negative regulators of IL-17A-producing {gamma}{delta} T cell subsets. Together, these data demonstrate how lung {gamma}{delta} T cell subsets are differentially controlled by co-inhibitory molecules in steady-state and cancer.

immunology↗

bioRxiv2020

Ly6C defines a subset of memory-like CD27+ γδ T cells with inducible cancer-killing function

In mice, IFN{gamma}-producing {gamma}{delta} T cells that express the co-stimulatory molecule, CD27, play a critical role in host defence and anti-tumour immunity. However, their phenotypic diversity, composition in peripheral and secondary lymphoid organs, similarity to {beta} T cells as well as homology with human {gamma}{delta} T cells is poorly understood. Here, using single cell RNA sequencing, we show that CD27+ {gamma}{delta} T cells consist of two major clusters, which are distinguished by expression of Ly6C. We demonstrate that CD27+Ly6C-- {gamma}{delta} T cells exhibit a naive T cell-like phenotype, whereas CD27+Ly6C+ {gamma}{delta} T cells display a memory-like phenotype, produce several NK cell-related and cytotoxic molecules and are highly similar to both mouse CD8+ T cells and mature human {gamma}{delta} T cells. In a breast cancer mouse model, depletion of CD27+ {gamma}{delta} T cells failed to affect tumour growth, but these cells could be coerced into killing cancer cells after expansion ex vivo. These results identify novel subsets of {gamma}{delta} T cells in mice that are comparable to human {gamma}{delta} T cells, opening new opportunities for {gamma}{delta} T cell-based cancer immunotherapy research.

immunology↗

bioRxiv2020

The MSP-RON axis stimulates cancer cell growth in models of triple negative breast cancer

Triple negative breast cancer is the most aggressive subtype of breast cancer with poor prognosis and high rates of relapse. The lack of actionable targets for TNBC has contributed to the high mortality rates of this disease, and new candidate molecules for potential manipulation are urgently required. Here, we show that macrophage-stimulating protein (MSP) and its tyrosine kinase receptor, RON, are potent drivers of cancer cell growth and tumor progression in a mouse model of TNBC driven by the loss of Trp53 and Brca1. After comparison of two genetically engineered mouse models of TNBC, we found that mammary tumors from K14-Cre;Brca1F/F;Trp53F/F (KB1P) mice exhibit high endogenous levels of MSP and RON expression. We show that MSP stimulates AKT and ERK1/2 activation as well as cancer cell growth in KB1P cell lines, while genetic and pharmacological inhibition of RON prevents these effects. Similarly, KB1P tumor progression in mice was robustly attenuated by treatment with a RON inhibitor with accompanied reduction in the proliferation marker, Ki-67. Our findings in a mouse model where MSP and RON expression are naturally increased provide evidence that this receptor and its ligand are viable candidate molecules for targeted treatment of TNBC.

cancer biology↗