Transcriptome Signature of Vγ9Vδ2 T Cells Treated With Phosphoantigens and Notch Inhibitor Reveals Interplay Between TCR and Notch Signaling Pathways.

Ayush Madhok,Sanjeev Galande,Chinna Susan Philip,Shalini Kashipathi Sureshbabu,Shubhada Chiplunkar,Sajad Ahmad Bhat

doi:10.3389/fimmu.2021.660361

Abstract

Gamma delta (γδ) T cells, especially the Vγ9Vδ2 subtype, have been implicated in cancer therapy and thus have earned the spotlight in the past decade. Although one of the most important properties of γδ T cells is their activation by phosphoantigens, which are intermediates of the Mevalonate and Rohmer pathway of isoprenoid biosynthesis, such as IPP and HDMAPP, respectively, the global effects of such treatments on Vγ9Vδ2 T cells remain elusive. Here, we used the high-throughput transcriptomics approach to elucidate the transcriptional changes in human Vγ9Vδ2 T cells upon HDMAPP, IPP, and anti-CD3 treatments in combination with interleukin 2 (IL2) cytokine stimulation. These activation treatments exhibited a dramatic surge in transcription with distinctly enriched pathways. We further assessed the transcriptional dynamics upon inhibition of Notch signaling coupled with activation treatments. We observed that the metabolic processes are most affected upon Notch inhibition via GSI-X. The key effector genes involved in gamma–delta cytotoxic function were downregulated upon Notch blockade even in combination with activation treatment, suggesting a transcriptional crosstalk between T-cell receptor (TCR) signaling and Notch signaling in Vγ9Vδ2 T cells. Collectively, we demonstrate the effect of the activation of TCR signaling by phosphoantigens or anti-CD3 on the transcriptional status of Vγ9Vδ2 T cells along with IL2 stimulation. We further show that the blockade of Notch signaling antagonistically affects this activation.

Highlights

Human gd T cells get activated and proliferate in response to non-peptidic compounds derived from pathogenic microbes including Mycobacterium tuberculosis [9,10,11]. gd T cells recognize non-peptide phosphoantigens produced via mevalonate pathway such as isopentenyl pyrophosphate (IPP) [12]
The present study reveals the transcriptional dynamics during gd T cell activation
We showed that stimulations of T-cell receptor (TCR) using phosphoantigen (IPP and HDMAPP) and anti-CD3 antibody treatments in vitro can lead to the induction of both distinct and similar transcriptional programs in Vg9Vd2 T cells, the effector molecules such as IFN-g, Perforin-1 (PRF1), and tumor necrosis factor receptor superfamily (TNFRSF) members are positively regulated across various activation methods

Summary

INTRODUCTION

Gd T cells are a small subgroup of T cells, accounting for about 1%– 5% of peripheral T-cell populations [1]. gd T cells express different T-cell receptors (TCRs)—g and d chains—unlike the classical ab T cells [2]. Vg9Vd2 T cells show dramatic plasticity, antigen presentation, and abundant inflammatory-cytokine production [8] In light of these features, Vg9Vd2 T cells are being studied extensively for cancer immunotherapy. Upon hyperactivation of the mevalonate pathway, IPP is overproduced, and activation of Vg9Vd2 T cells by IPP is dependent on the transmembrane butyrophillin molecules [15, 19, 20]. Sensitivity of these tumors to lysis by Vg9Vd2 T cells increases upon treatment with aminobisphosphonates, which leads to accumulation of intracellular IPP [21, 22]. This study provides important cues towards designing better combinations of target-specific molecules along with the current gd T cell-based immunotherapies

MATERIALS AND METHODS

RESULTS

DISCUSSION

DATA AVAILABILITY STATEMENT