Tumor-infiltrating γδ T cells as targets of immune checkpoint blockade in melanoma.

Melanoma is one of the most sensitive tumors to immune modulation, and the major challenge for melanoma patients' survival is immune checkpoint inhibitor (ICI) therapy. γδ T lymphocytes play an antitumoral role in a broad variety of tumors including melanoma and they are optimal candidates for cellular immunotherapy. Thus, a comprehensive analysis of the correlation between γδ T cells and immune checkpoint receptors in the context of melanoma was conducted, with the aim of devising an innovative combined immunotherapeutic strategy. In this study, using the GEPIA2.0 database, a significant positive correlation was observed between the expression of γδ T cell-related genes (TRGC1, TRGC2, TCRD) and immune checkpoint genes (PDCD1, HAVCR2, LAG3), highlighting the potential role of γδ T cells in the immune response within melanoma. Moreover, flow cytometry analysis unveiled a significant augmentation in the population of γδ T cells within melanoma lesions, which exhibited the expression of immune checkpoint receptors including LAG3, TIM3, and PD1. Analysis of single-cell RNA sequencing data revealed a significant enrichment and functional reprogramming of γδ T cell clusters in response to ICIs. Interestingly, the effects of ICI therapy varied between Vδ1 and Vδ2 γδ T cell subsets, with distinct changes in gene expression patterns. Last, a correlation analysis between γδ T cell abundance, immune checkpoint gene expression, and clinical outcomes in melanoma patients showed that low expression of immune checkpoint genes, including LAG3, HAVCR2, and PDCD1, was associated with improved 1-year overall survival, emphasizing the significance of these genes in predicting patient outcomes, potentially outweighing the impact of γδ T cell abundance. This study offers critical insights into the dynamic interaction between γδ T cells, immune checkpoint receptors, and melanoma, providing valuable perspectives for potential therapeutic avenues and predictive markers in this intricate interplay.

γδ T cells and their clinical application in colon cancer.

In recent years, research has focused on colorectal cancer to implement modern treatment approaches to improve patient survival. In this new era, γδ T cells constitute a new and promising candidate to treat many types of cancer because of their potent killing activity and their ability to recognize tumor antigens independently of HLA molecules. Here, we focus on the roles that γδ T cells play in antitumor immunity, especially in colorectal cancer. Furthermore, we provide an overview of small-scale clinical trials in patients with colorectal cancer employing either in vivo activation or adoptive transfer of ex vivo expanded γδ T cells and suggest possible combinatorial approaches to treat colon cancer.

Monoclonal Gammopathies and the Bone Marrow Microenvironment: From Bench to Bedside and Then Back Again.

Multiple myeloma (MM) is an incurable hematologic malignancy characterized by a multistep evolutionary pathway, with an initial phase called monoclonal gammopathy of undetermined significance (MGUS), potentially evolving into the symptomatic disease, often preceded by an intermediate phase called "smoldering" MM (sMM). From a biological point of view, genomic alterations (translocations/deletions/mutations) are already present at the MGUS phase, thus rendering their role in disease evolution questionable. On the other hand, we currently know that changes in the bone marrow microenvironment (TME) could play a key role in MM evolution through a progressive shift towards a pro-inflammatory and immunosuppressive shape, which may drive cancer progression as well as clonal plasma cells migration, proliferation, survival, and drug resistance. Along this line, the major advancement in MM patients' survival has been achieved by the introduction of microenvironment-oriented drugs (including immunomodulatory drugs and monoclonal antibodies). In this review, we summarized the role of the different components of the TME in MM evolution from MGUS as well as potential novel therapeutic targets/opportunities.

Metabolic Changes in Tumor Microenvironment: How Could They Affect γδ T Cells Functions?

The metabolic changes that occur in tumor microenvironment (TME) can influence not only the biological activity of tumor cells, which become more aggressive and auto sustained, but also the immune response against tumor cells, either producing ineffective responses or polarizing the response toward protumor activity. γδ T cells are a subset of T cells characterized by a plasticity that confers them the ability to differentiate towards different cell subsets according to the microenvironment conditions. On this basis, we here review the more recent studies focused on altered tumor metabolism and γδ T cells, considering their already known antitumor role and the possibility of manipulating their effector functions by in vitro and in vivo approaches. γδ T cells, thanks to their unique features, are themselves a valid alternative to overcome the limits associated with the use of conventional T cells, such as major histocompatibility complex (MHC) restriction, costimulatory signal and specific tumor-associated antigen recognition. Lipids, amino acids, hypoxia, prostaglandins and other metabolic changes inside the tumor microenvironment could reduce the efficacy of this important immune population and polarize γδ T cells toward IL17 producing cells that play a pro tumoral role. A deeper knowledge of this phenomenon could be helpful to formulate new immunotherapeutic approaches that target tumor metabolisms.

Cell quality evaluation with gene expression analysis of spheroids (3D) and adherent (2D) adipose stem cells.

Adipose stem cells (ASCs) represent a reliable source of stem cells with a widely demonstrated potential in regenerative medicine and tissue engineering applications. New recent insights suggest that three-dimensional (3D) models may closely mimic the native tissue properties; spheroids from adipose derived stem cells (SASCs) exhibit enhanced regenerative abilities compared with those of 2D models. Stem cell therapy success is determined by "cell-quality"; for this reason, the involvement of stress signals and cellular aging need to be further investigated. Here, we performed a comparative analysis of genes connected with stemness, aging, telomeric length and oxidative stress, in 3D and 2D primary cultures. The expression levels of stemness-related markers and anti-aging Sirtuin1 were significantly up-regulated (P < 0.001) in SASCs-3D while gene expression of aging-related p16INK4a was increased in ASCs-2D (P < 0.001). The 3D and 2D cultures also had a different gene expression profile for genes related to telomere maintenance (Shelterin complex, RNA Binding proteins and DNA repair genes) (P < 0.01 and P < 0.001) and oxidative stress (aldehyde dehydrogenase class1 and 3) (P < 0.05, P < 0.01 and P < 0.001) and presented a striking large variation in their cellular redox state. Based on our findings, we propose a "cell quality" model of SASCs, highlighting a precise molecular expression of several genes involved with stemness (SOX2, POU5F1 and NANOG), anti-aging (SIRT1), oxidative stress (ALDH3) and telomeres maintenance.

Analysis of colon-infiltrating γδ T cells in chronic inflammatory bowel disease and in colitis-associated cancer.

Inflammatory bowel disease (IBD) remains a global health problem with a significant percentage of patients progressing to chronic inflammation and colitis-associated cancer (CAC). Whether or not γδ T cells contribute to initiation and maintenance of inflammation in IBD and in the development of CAC is not known. We have evaluated the frequency, phenotype, and functions of γδ T cells among tissue-infiltrating lymphocytes in healthy donors and IBD and CAC patients. Results show that Vδ1 T cells are the dominant γδ T-cell population in healthy tissue, whereas Vδ2 T significantly abound in chronic IBD. Vδ2 T cells produce more IFN-γ, TNF-α, and IL-17 than Vδ1 T cells in chronic inflamed IBD. In CAC patients no significant cytokine production was detected in tissue-resident Vδ1 T cells, but Vδ2 T cells produced remarkable amounts of IFN-γ and TNF-α; these data were confirmed by the analysis of an independent cohort of IBD transcriptomes. Moreover, transcriptomes of IBD patients revealed a clear-cut clusterization of genes related with the maintenance of the inflammatory status. In conclusion, our results demonstrating that Vδ2 T cells have a proinflammatory profile in chronic IBD are suggestive of their participation in IBD and CAC pathogenesis.