Optimization of methods for peripheral blood mononuclear cells isolation and expansion of human gamma delta T cells

Advancements in γδT cell engineering: paving the way for enhanced cancer immunotherapy

Comprising only 1-10% of the circulating T cell population, γδT cells play a pivotal role in cancer immunotherapy due to their unique amalgamation of innate and adaptive immune features. These cells can secrete cytokines, including interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), and can directly eliminate tumor cells through mechanisms like Fas/FasL and antibody-dependent cell-mediated cytotoxicity (ADCC). Unlike conventional αβT cells, γδT cells can target a wide variety of cancer cells independently of major histocompatibility complex (MHC) presentation and function as antigen-presenting cells (APCs). Their ability of recognizing antigens in a non-MHC restricted manner makes them an ideal candidate for allogeneic immunotherapy. Additionally, γδT cells exhibit specific tissue tropism, and rapid responsiveness upon reaching cellular targets, indicating a high level of cellular precision and adaptability. Despite these capabilities, the therapeutic potential of γδT cells has been hindered by some limitations, including their restricted abundance, unsatisfactory expansion, limited persistence, and complex biology and plasticity. To address these issues, gene-engineering strategies like the use of chimeric antigen receptor (CAR) T therapy, T cell receptor (TCR) gene transfer, and the combination with γδT cell engagers are being explored. This review will outline the progress in various engineering strategies, discuss their implications and challenges that lie ahead, and the future directions for engineered γδT cells in both monotherapy and combination immunotherapy.

Re-generation of cytotoxic γδT cells with distinctive signatures from human γδT-derived iPSCs

For a long time, ex vivo-expanded peripheral-blood-derived γδT cell (PBγδT)-based immunotherapy has been attractive, and clinical trials have been undertaken. However, the difficulty in expanding cytotoxic γδT cells to an adequate number has been a major limitation to the efficacy of treatment in most cases. We successfully re-generated γδT cells from γδT cell-derived human induced pluripotent stem cells (iPSCs). The iPSC-derived γδT cells (iγδTs) killed several cancer types in a major histocompatibility complex (MHC)-unrestricted manner. Single-cell RNA sequencing (scRNA-seq) revealed that the iγδTs were identical to a minor subset of PBγδTs. Compared with a major subset of PBγδTs, the iγδTs showed a distinctive gene expression pattern: lower CD2, CD5, and antigen-presenting genes; higher CD7, KIT, and natural killer (NK) cell markers. The iγδTs expressed granzyme B and perforin but not interferon gamma (IFNγ). Our data provide a new source for γδT cell-based immunotherapy without quantitative limitation.

Human Vδ2 T Cells and Their Versatility for Immunotherapeutic Approaches

Gamma/delta (γδ) T cells are innate-like immune effectors that are a critical component linking innate and adaptive immune responses. They are recognized for their contribution to tumor surveillance and fight against infectious diseases. γδ T cells are excellent candidates for cellular immunotherapy due to their unique properties to recognize and destroy tumors or infected cells. They do not depend on the recognition of a single antigen but rather a broad-spectrum of diverse ligands through expression of various cytotoxic receptors. In this manuscript, we review major characteristics of the most abundant circulating γδ subpopulation, Vδ2 T cells, their immunotherapeutic potential, recent advances in expansion protocols, their preclinical and clinical applications for several infectious diseases and malignancies, and how additional modulation could enhance their therapeutic potential.

γδ T Cell-Based Adoptive Cell Therapies Against Solid Epithelial Tumors

ABSTRACT

Conventionally, adoptive cell therapies have been developed and optimized using αβ T cells. However, the understudied and less abundant γδ T cells offer unique advantages to the immunotherapy field especially for therapies against solid tumors. Recently, γδ T-cell potential against a broad spectrum of malignant cells has been demonstrated in the preclinical setting. In the clinic, γδ T-cell-based immunotherapies have proven to be safe; however, their efficacy needs improvement. Considering the growing body of literature reflecting the increasing interest in γδ T cells, we sought to capture the current topics of discussion in the field, pertaining to their use in adoptive immunotherapy. We aimed to compile information about γδ T-cell enhancement in terms of expansion, phenotype, and inhibitory receptors, in addition to the latest advances in preclinical and clinical research using γδ T cells specifically against solid epithelial tumors.

Combinational therapeutics to combat cancer

Mono-therapeutics is rarely effective as a treatment option, which limits the survival of patients in advanced grade aggressive cancers. Combinational therapeutics (multiple drugs for multiple targets) to combat cancer is gaining momentum in recent years. Hence, it is of interest to document known data for combinational therapeutics in cancer treatment. An amalgamation of therapeutic agents enhances the efficacy and potency of the therapy. Combinational therapy can potentially target multiple pathways that are necessary for the cancer cells to proliferate, and/or target molecules, which may help cancer to become more aggressive and metastasize. In this review, we discuss combinational therapeutics, which include human γδ T cells in combinations with biologically active anti-cancer molecules, which synergistically may produce promising combinational therapeutics.