CD277 agonist enhances the immunogenicity of relapsed/refractory acute myeloid leukemia towards Vδ2+ T cell cytotoxicity

γδ T cells in hematological malignancies: mechanisms and therapeutic strategies

γδ T cells are a unique subset of lymphocytes with both innate and adaptive features. They recognize and eradicate various hematological malignancies through different mechanisms, employing factors including γδ TCR, NKR, NKG2D, TRAIL, and perforin/granzyme. They also modulate other immune cells to enhance their antitumor activity. Moreover, γδ T cells have potent antiviral functions after hematopoietic stem cell transplantation (HSCT), which may improve the outcome of patients with hematological malignancies. In this review, we summarize the current knowledge on γδ T cell biology and function in hematological malignancies and HSCT complications. We also discuss the challenges and limitations of the clinical application of γδ T cells, such as their low frequency in peripheral blood and heterogeneity among different subsets. We then highlight some promising strategies for γδ T cell-based therapy, such as using agonist antibodies, cell engagers, or genetic modification technology. Furthermore, we review the recent clinical trials evaluating the safety and efficacy of γδ T-cell therapy in different hematological malignancies. In conclusion, γδ T cells represent a promising immunotherapeutic tool for hematological malignancies that deserves further exploration.

Landscape of unconventional γδ T cell subsets in cancer

T cells are broadly categorized into two groups, namely conventional and unconventional T cells. Conventional T cells are the most prevalent and well-studied subset of T cells. On the other hand, unconventional T cells exhibit diverse functions shared between innate and adaptive immune cells. During recent decades, γδ T cells have received attention for their roles in cancer immunity. These cells can detect various molecules, such as lipids and metabolites. Also, they are known for their distinctive ability to recognize and target cancer cells in the tumor microenvironment (TME). This feature of γδ T cells could provide a unique therapeutic tool to fight against cancer. Understanding the role of γδ T cells in TME is essential to prepare the groundwork to use γδ T cells for clinical purposes. Here, we provide recent knowledge regarding the role γδ T cell subsets in different cancer types.

Recent advance in phytonanomedicine and mineral nanomedicine delivery system of the treatment for acute myeloid leukemia

Acute myeloid leukemia (AML) is an invasive hematopoietic malignancy caused by excessive proliferation of myeloblasts. Classical chemotherapies and cell transplantation therapies have remarkable efficacy in AML treatment; however, 30-40% of patients relapsed or had refractory disease. The resistance of AML is closely related to its inherent cytogenetics or various gene mutations. Recently, phytonanomedicine are found to be effective against resistant AML cells and have become a research focus for nanotechnology development to improve their properties, such as increasing solubility, improving absorption, enhancing bioavailability, and maintaining sustained release and targeting. These novel phytonanomedicine and mineral nanomedicine, including nanocrystals, nanoemulsion, nanoparticles, nanoliposome, and nanomicelles, offer many advantages, such as flexible dosages or forms, multiple routes of administration, and curative effects. Therefore, we reviewed the application and progress of phytomedicine in AML treatment and discussed the limitations and future prospects. This review may provide a solid reference to guide future research on AML treatment.

Improved Vδ2+ T cells recovery correlates to reduced incidences of mortality and relapse in acute myeloid leukemia after hematopoietic transplantation

Acute myeloid leukemia (AML) patients can benefit from allogeneic hematopoietic cell transplantation (alloHCT) and achieve long-term remission. Recovery of T cell quantity and quality is critical to reduce the incidences of life-threatening complications after alloHCT. Although the general recovery level of γδ T cells is recognized to be associated with outcomes of patients who suffered from various hematological diseases and received alloHCT, the correlation between γδ T cell subsets and the prognosis in AML patients following transplantation remains to be investigated. In the current study, the recoveries of T cell subpopulations in 103 AML patients were dissected at different time points after haploidentical HCT (haploHCT). Statistical analyses showed that the absolute number of Vδ2⁺ T cells on day 90 was an independent risk factor for predicting 2-year OS in AML patients following haploHCT. The survival advantage from the improved recovery of day-90 Vδ2⁺ T cells was attributed to reducing the infection-related mortality. Consistently, lower 2-year non-relapse mortality was found in recipients with higher day-90 levels of Vδ2⁺ T cells. Notably, day-270 Vδ2⁺ T cell numbers reversely correlated to both 2-year and 5-year probabilities of relapse in this scenario. These results highlighted the significant correlation of Vδ2⁺ T cells recovery with long-term survival and relapse after alloHCT, suggesting that Vδ2⁺ T cells-based immune strategies may help control infectious complications and leukemia recurrence in AML patients.

The emerging roles of γδ T cells in cancer immunotherapy

Current cancer immunotherapies are primarily predicated on αβ T cells, with a stringent dependence on MHC-mediated presentation of tumour-enriched peptides or unique neoantigens that can limit their efficacy and applicability in various contexts. After two decades of preclinical research and preliminary clinical studies involving very small numbers of patients, γδ T cells are now being explored as a viable and promising approach for cancer immunotherapy. The unique features of γδ T cells, including their tissue tropisms, antitumour activity that is independent of neoantigen burden and conventional MHC-dependent antigen presentation, and combination of typical properties of T cells and natural killer cells, make them very appealing effectors in multiple cancer settings. Herein, we review the main functions of γδ T cells in antitumour immunity, focusing on human γδ T cell subsets, with a particular emphasis on the differences between Vδ1⁺ and Vδ2⁺ γδ T cells, to discuss their prognostic value in patients with cancer and the key therapeutic strategies that are being developed in an attempt to improve the outcomes of these patients.