Butyrophilin molecules govern γδ T cell reactivity against phosphoantigens

Owing to their antitumor and major histocompatibility complex (MHC)-independent capacities, γδ T cells have gained popularity in adoptive T-cell immunotherapy in recent years. However, many unknowns still exist regarding γδ T cells, and few clinical data have been collected. Therefore, this review aims to describe all the main features of the applications of γδ T cells and provide a systematic view of current γδ T-cell immunotherapy. Specifically, this review will focus on how γδ T cells performed in treating cancers in clinics, on the γδ T-cell clinical trials that have been conducted to date, and the role of γδ T cells in the pharmaceutical industry.

Section: Gd T-cell Immunotherapy In Cancermentioning

confidence: 99%

A close look at current γδ T-cell immunotherapy

Yang

Zhou

2023

“…First, we have shown that Vd2+ T-cells in circulation express various activation markers. Vd2+ T-cell recognition has been widely documented to be due to recognition of phosphoantigens via BTN3A1 and the TCR (6)(7)(8). Recognition also occurs via NKG2D and the recognition of stress ligands MICA/B and ULBPs (11,65,66).…”

Section: Discussionmentioning

confidence: 99%

“…This cell population has also been implicated in anti-tumour responses due to their ability to recognise phosphoantigens from dysregulated mevalonate pathways. Full activation occurs via the recruitment of butyrophilin 3A1 (BTN3A1), which together with BTN2A1 engages the T-cell receptor (TCR) (6)(7)(8)(9)(10). In addition to recognising phosphoantigens, Vg9Vd2 T-cells can also recognise upregulated cell stress ligands through expression of various NK associated activatory receptors (11).…”

Section: Introductionmentioning

confidence: 99%

Releasing the restraints of Vγ9Vδ2 T-cells in cancer immunotherapy

Ridgley

Caron²,

Dalgleish³

et al. 2023

ObjectivesVγ9Vδ2 T-cells are a subset of T-cells with a crucial role in immunosurveillance which can be activated and expanded by multiple means to stimulate effector responses. Little is known about the expression of checkpoint molecules on this cell population and whether the ligation of these molecules can regulate their activity. The aim of this study was to assess the expression of both activatory and inhibitory receptors on Vγ9Vδ2 T-cells to assess potential avenues of regulation to target with immunotherapy.MethodsExpression of various activatory and inhibitory receptors was assessed on Vγ9Vδ2 T-cells by flow cytometry following activation and expansion using zoledronic acid (ZA) and Bacillus Calmette-Guérin (BCG). Expression of these markers and production of effector molecules was also examined following co-culture with various tumour cell targets. The effect of immune checkpoint blockade on Vγ9Vδ2 T-cells was also explored.ResultsVγ9Vδ2 T-cells expressed high levels of activatory markers both at baseline and following stimulation. Vγ9Vδ2 T-cells expressed variable levels of inhibitory checkpoint receptors with many being upregulated following stimulation. Expression of these markers is further modulated upon co-culture with tumour cells with changes reflecting activation and effector functions. Despite their high expression of inhibitory receptors when cultured with tumour cells expressing cognate ligands there was no effect on Vδ2+ T-cell cytotoxic capacity or cytokine production with immune checkpoint blockade.ConclusionsOur work suggests the expression of checkpoint receptors present on Vγ9Vδ2 T-cells which may provide a mechanism with the potential to be utilised by tumour cells to subvert Vγ9Vδ2 T-cell cytotoxicity. This work suggests important candidates for blockade by ICI therapy in order to increase the successful use of Vγ9Vδ2 T-cells in immunotherapy.

“…This concept is based on the anti-tumor activity of g9d2 T cells, which are important players in the recognition of foreign pathogens, virally infected cells, and also cancer cells (14). Vg9d2 T cells, a specific gdT cell subset mainly found in the blood, recognize members of the butyrophilin (BTN) family, namely BTN2A1, through the gamma chain of their Vg9d2TCR, and additionally require BTN3A1 expression on the tumor cells for full activation (15)(16)(17). Recognition of the BTN2A1-BTN3A1 complex is induced by an intra-cellular accumulation of phosphoantigens (pAg) that can bind to the intracellular B30.2 domain of BTN3A1, which is modulated by RhoB (18,19).…”

Section: Introductionmentioning

confidence: 99%

“…Critical for the GAB concept remains the rather low affinity of the Vg9d2 TCR for its ligands, which has been reported in the µM range (15,16), a couple of magnitudes lower than the high affinity antibody derived domains generally used for tumor binding in TCEs. For abTCR based TCEs, like Tebentafusp, the consensus is that affinity maturation of the abTCR from µM to pM is required to create a functional TCE (26).…”

Section: Introductionmentioning

confidence: 99%

The making of multivalent gamma delta TCR anti-CD3 bispecific T cell engagers

Diest

Nicolasen²,

Kramer³

et al. 2023

IntroductionWe have recently developed a novel T cell engager concept by utilizing γ9δ2TCR as tumor targeting domain, named gamma delta TCR anti-CD3 bispecific molecule (GAB), targeting the phosphoantigen-dependent orchestration of BTN2A1 and BTN3A1 at the surface of cancer cells. GABs are made by the fusion of the ectodomains of a γδTCR to an anti-CD3 single chain variable fragment (scFv) (γδECTO-αCD3), here we explore alternative designs with the aim to enhance GAB effectivity.MethodsThe first alternative design was made by linking the variable domains of the γ and δ chain to an anti-CD3 scFv (γδVAR-αCD3). The second alternative design was multimerizing γδVAR-αCD3 proteins to increase the tumor binding valency. Both designs were expressed and purified and the potency to target tumor cells by T cells of the alternative designs was compared to γδECTO-αCD3, in T cell activation and cytotoxicity assays.Results and discussionThe γδVAR-αCD3 proteins were poorly expressed, and while the addition of stabilizing mutations based on finding for αβ single chain formats increased expression, generation of meaningful amounts of γδVAR-αCD3 protein was not possible. As an alternative strategy, we explored the natural properties of the original GAB design (γδECTO-αCD3), and observed the spontaneous formation of γδECTO-αCD3-monomers and -dimers during expression. We successfully enhanced the fraction of γδECTO-αCD3-dimers by shortening the linker length between the heavy and light chain in the anti-CD3 scFv, though this also decreased protein yield by 50%. Finally, we formally demonstrated with purified γδECTO-αCD3-dimers and -monomers, that γδECTO-αCD3-dimers are superior in function when compared to similar concentrations of monomers, and do not induce T cell activation without simultaneous tumor engagement. In conclusion, a γδECTO-αCD3-dimer based GAB design has great potential, though protein production needs to be further optimized before preclinical and clinical testing.