Leveraging Vγ9Vδ2 T cells against prostate cancer through a VHH-based PSMA-Vδ2 bispecific T cell engager.

Vγ9Vδ2 T cells constitute a homogeneous effector T cell population that lyses tumors of different origin, including the prostate. We generated a bispecific T cell engager (bsTCE) to direct Vγ9Vδ2 T cells to PSMA prostate cancer (PCa) cells. The PSMA-Vδ2 bsTCE triggered healthy donor and PCa patient-derived Vγ9Vδ2 T cells to lyse PSMA PCa cell lines and patient-derived tumor cells while sparing normal prostate cells and enhanced Vγ9Vδ2 T cell antigen cross-presentation to CD8 T cells.

Vδ2 T-cell engagers bivalent for Vδ2-TCR binding provide anti-tumor immunity and support robust Vγ9Vδ2 T-cell expansion.

Background: Vγ9Vδ2 T-cells are antitumor immune effector cells that can detect metabolic dysregulation in cancer cells through phosphoantigen-induced conformational changes in the butyrophilin (BTN) 2A1/3A1 complex. In order to clinically exploit the anticancer properties of Vγ9Vδ2 T-cells, various approaches have been studied including phosphoantigen stimulation, agonistic BTN3A-specific antibodies, adoptive transfer of expanded Vγ9Vδ2 T-cells, and more recently bispecific antibodies. While Vγ9Vδ2 T-cells constitute a sizeable population, typically making up ~1-10% of the total T cell population, lower numbers have been observed with increasing age and in the context of disease.

An organotypic human melanoma-in-skin model as an tool for testing Vγ9Vδ2-T cell-based immunotherapy.

Background: Despite considerable advancements in cancer immunotherapy, advanced melanoma still presents a substantial clinical challenge. In an effort to explore treatment options, we examined the immunotherapeutic potential of effector Vγ9Vδ2-T cells in a three-dimensional (3D) human organotypic melanoma-in-skin (Mel-RhS) model.

Materials And Methods: Vγ9Vδ2-T cells were introduced into Mel-RhS via intradermal injection and cultured within the tissue microenvironment for up to 3 days.

Enhanced CD1d phosphatidylserine presentation using a single-domain antibody promotes immunomodulatory CD1d-TIM-3 interactions.

Background: CD1d is a monomorphic major histocompatibility complex class I-like molecule that presents lipid antigens to distinct T-cell subsets and can be expressed by various malignancies. Antibody-mediated targeting of CD1d on multiple myeloma cells was reported to induce apoptosis and could therefore constitute a novel therapeutic approach.

Methods: To determine how a CD1d-specific single-domain antibody (VHH) enhances binding of the early apoptosis marker annexin V to CD1d tumor cells we use in vitro cell-based assays and CRISPR-Cas9-mediated gene editing, and to determine the structure of the VHH1D17-CD1d(endogenous lipid) complex we use X-ray crystallography.

A Bispecific γδ T-cell Engager Targeting EGFR Activates a Potent Vγ9Vδ2 T cell-Mediated Immune Response against EGFR-Expressing Tumors.

Vγ9Vδ2 T cells are effector cells with proven antitumor efficacy against a broad range of cancers. This study aimed to assess the antitumor activity and safety of a bispecific antibody directing Vγ9Vδ2 T cells to EGFR-expressing tumors. An EGFR-Vδ2 bispecific T-cell engager (bsTCE) was generated, and its capacity to activate Vγ9Vδ2 T cells and trigger antitumor activity was tested in multiple in vitro, in vivo, and ex vivo models.