Search results for "δ"

Vγ9Vδ2 T Cells as Strategic Weapons to Improve the Potency of Immune Checkpoint Blockade and Immune Interventions in Human Myeloma

2018

The advent of immune checkpoint (ICP) blockade has introduced an unprecedented paradigm shift in the treatment of cancer. Though very promising, there is still a substantial proportion of patients who do not respond or develop resistance to ICP blockade. In vitro and in vivo models are eagerly needed to identify mechanisms to maximize the immune potency of ICP blockade and overcome primary and acquired resistance to ICP blockade. Vγ9Vδ2 T cells isolated from the bone marrow (BM) from multiple myeloma (MM) are excellent tools to investigate the mechanisms of resistance to PD-1 blockade and to decipher the network of mutual interactions between PD-1 and the immune suppressive tumor microenvir…

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

2019

Abstract 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 inflame…

CD3ε Expression Defines Functionally Distinct Subsets of Vδ1 T Cells in Patients With Human Immunodeficiency Virus Infection

2018

Human γδ T cells expressing the Vδ1 T cell receptor (TCR) recognize self and microbial antigens and stress-inducible molecules in a major histocompatibility complex -unrestricted manner and are an important source of innate interleukin-17. Vδ1 T cells are expanded in the circulation and intestines of patients with human immunodeficiency virus (HIV) infection. In the present study, we show that patients with HIV have elevated frequencies, but not absolute numbers, of circulating Vδ1 T cells compared to control subjects. This increase was most striking in the patients with Candida albicans co-infection. Using flow cytometry and confocal microscopy, we identify two populations of Vδ1 T cells, …

PPARδ Modulation by GW501516: An Unsuccessful Exercise Mimetic.

2017

Chemotherapy accelerates immune-senescence and functional impairments of Vδ2pos T cells in elderly patients affected by liver metastatic colorectal c…

2019

Abstract Human (gamma delta) γδ T cells are unconventional innate-like lymphocytes displaying a broad array of anti-tumor activities with promising perspectives in cancer immunotherapy. In this context, Vδ2pos T cells represent the preferential target of several immunotherapy protocols against solid tumors. However, the impact of both aging and chemotherapy (CHT) on Vδ2pos T cells is still unknown. The present study evaluates with multi-parametric flow cytometry the frequencies, terminal differentiation, senescence and effector-functions of peripheral blood and tumor infiltrating Vδ2pos T cells purified from liver metastases (CLM) of patients affected by colorectal cancer (CRC) compared to …

Activation and selective IL-17 response of human Vγ9Vδ2 T lymphocytes by TLR-activated plasmacytoid dendritic cells.

2016

// Elena Lo Presti 1,2 , Nadia Caccamo 1,2 , Valentina Orlando 1,2 , Francesco Dieli 1,2 and Serena Meraviglia 1,2 1 Central Laboratory of Advanced Diagnosis and Biomedical Research (CLADIBIOR), University of Palermo, Palermo, Italy 2 Department of Biopathology and Medical Biotechnologies (DIBIMED), University of Palermo, Palermo, Italy Correspondence to: Serena Meraviglia, email: // Keywords : γδ T cells, plasmacytoid dendritic cells, IL-17, TLR activation, proliferation, Immunology and Microbiology Section, Immune response, Immunity Received : July 20, 2016 Accepted : August 02, 2016 Published :August 31, 2016 Abstract Vγ9Vδ2 T cells and plasmacytoid dendritic cells (pDCs) are two distinc…

Deciphering human γδ T cell response in cancer: Lessons from tumor‐infiltrating γδ T cells

2020

The finding that γδ T cells are present among tumor-infiltrating lymphocytes in humans suggests they participate in tumor immune surveillance, but their relevance is unclear because the relative abundance of tumor-infiltrating γδ T cells correlates with positive or negative, or even do not correlate with prognosis. This likely depends on the fact that tumor-infiltrating γδ T cells may play substantially different effector or regulatory functions, and correlation with patient's prognosis relies on distinct γδ T cell subsets in the context of the tumor. There is interest to exploit γδ T cells in tumor immunotherapy, but to make this approach successful there is urgent need to fully understand…

Current advances in γδ T cell-based tumor immunotherapy

2017

γδ T cells are a minor population (~5%) of CD3 T cells in the peripheral blood, but abound in other anatomic sites such as the intestine or the skin. There are two major subsets of γδ T cells: those that express Vd1 gene, paired with different Vγ elements, abound in the intestine and the skin, and recognize the major histocompatibility complex (MHC) class I-related molecules such as MHC class I-related molecule A, MHC class I-related molecule B, and UL16-binding protein expressed on many stressed and tumor cells. Conversely, γδ T cells expressing the Vδ2 gene paired with the Vγ9 chain are the predominant (50-90%) γδ T cell population in the peripheral blood and recognize phosphoant…

Human Vδ1+ T Cells in the Immune Response to Plasmodium falciparum Infection

2019

Naturally acquired protective immunity to Plasmodium falciparum malaria is mainly antibody-mediated. However, other cells of the innate and adaptive immune system also play important roles. These include so-called unconventional T cells, which express a γδ T-cell receptor (TCR) rather than the αβ TCR expressed by the majority of T cells-the conventional T cells. The γδ T-cell compartment can be divided into distinct subsets. One expresses a TCR involving Vγ9 and Vδ2, while another major subset uses instead a TCR composed of Vδ1 paired with one of several types of γ chains. The former of these subsets uses a largely semi-invariant TCR repertoire and responds in an innate-like fashion to pyro…

Myeloid-Derived Suppressor Cells Specifically Suppress IFN-γ Production and Antitumor Cytotoxic Activity of Vδ2 T Cells.

2018

γδ T cells represent less than 5% of circulating T cells; they exert a potent cytotoxic function against tumor or infected cells and secrete cytokines like conventional αβ T cells. As αβ T cells γδ T cells reside in the typical T cell compartments (the lymph nodes and spleen), but are more widely distributed in tissues throughout the body. For these reasons, some investigators are exploring the possibility of immunotherapies aimed to expand and activate Vδ2 T cells, or using them as Chimeric Antigen Receptor carriers. However, the role of immunosuppressive microenvironment on Vδ2 T cells during infections and cancers has not been completely elucidated. In particular, the effects of myeloid-…