γδ T cells are a kind of innate immune T cell. They have not attracted sufficient attention because they account for only a small proportion of all immune cells, and many basic factors related to these cells remain unclear. However, in recent years, with the rapid development of tumor immunotherapy, γδ T cells have attracted increasing attention because of their ability to exert cytotoxic effects on most tumor cells without major histocompatibility complex (MHC) restriction. An increasing number of basic studies have focused on the development, antigen recognition, activation, and antitumor immune response of γδ T cells. Additionally, γδ T cell-based immunotherapeutic strategies are being developed, and the number of clinical trials investigating such strategies is increasing. This review mainly summarizes the progress of basic research and the clinical application of γδ T cells in tumor immunotherapy to provide a theoretical basis for further the development of γδ T cell-based strategies in the future.
Humans ; Receptors, Antigen, T-Cell, gamma-delta ; Immunotherapy, Adoptive ; T-Lymphocytes ; Immunotherapy ; Neoplasms/therapy*

Humans ; Spleen ; CD8-Positive T-Lymphocytes ; Lymphocytes ; Lymphoma ; Receptors, Antigen, T-Cell, gamma-delta

Spinal cord injury (SCI) causes motor, sensory, and autonomic dysfunctions. The gut microbiome has an important role in SCI, while short-chain fatty acids (SCFAs) are one of the main bioactive mediators of microbiota. In the present study, we explored the effects of oral administration of exogenous SCFAs on the recovery of locomotor function and tissue repair in SCI. Allen's method was utilized to establish an SCI model in Sprague-Dawley (SD) rats. The animals received water containing a mixture of 150 mmol/L SCFAs after SCI. After 21 d of treatment, the Basso, Beattie, and Bresnahan (BBB) score increased, the regularity index improved, and the base of support (BOS) value declined. Spinal cord tissue inflammatory infiltration was alleviated, the spinal cord necrosis cavity was reduced, and the numbers of motor neurons and Nissl bodies were elevated. Enzyme-linked immunosorbent assay (ELISA), real-time quantitative polymerase chain reaction (qPCR), and immunohistochemistry assay revealed that the expression of interleukin (IL)‍-10 increased and that of IL-17 decreased in the spinal cord. SCFAs promoted gut homeostasis, induced intestinal T cells to shift toward an anti-inflammatory phenotype, and promoted regulatory T (Treg) cells to secrete IL-10, affecting Treg cells and IL-17⁺ γδ T cells in the spinal cord. Furthermore, we observed that Treg cells migrated from the gut to the spinal cord region after SCI. The above findings confirm that SCFAs can regulate Treg cells in the gut and affect the balance of Treg and IL-17⁺ γδ T cells in the spinal cord, which inhibits the inflammatory response and promotes the motor function in SCI rats. Our findings suggest that there is a relationship among gut, spinal cord, and immune cells, and the "gut-spinal cord-immune" axis may be one of the mechanisms regulating neural repair after SCI.
Animals ; Rats ; Interleukin-17 ; Rats, Sprague-Dawley ; Recovery of Function ; Spinal Cord Injuries/drug therapy* ; T-Lymphocytes, Regulatory ; Receptors, Antigen, T-Cell, gamma-delta/immunology*

The γδ T cells are unconventional lymphocytes that function in both innate and adaptive immune responses against various intracellular and infectious stresses. The γδ T cells can be exploited as cancer-killing effector cells since γδ TCRs recognize MHC-like molecules and growth factor receptors that are upregulated in cancer cells, and γδ T cells can differentiate into cytotoxic effector cells. However, γδ T cells may also promote tumor progression by secreting IL-17 or other cytokines. Therefore, it is essential to understand how the differentiation and homeostasis of γδ T cells are regulated and whether distinct γδ T cell subsets have different functions. Human γδ T cells are classified into Vδ2 and non-Vδ2 γδ T cells. The majority of Vδ2 γδ T cells are Vγ9δ2 T cells that recognize pyrophosphorylated isoprenoids generated by the dysregulated mevalonate pathway. In contrast, Vδ1 T cells expand from initially diverse TCR repertoire in patients with infectious diseases and cancers. The ligands of Vδ1 T cells are diverse and include the growth factor receptors such as endothelial protein C receptor. Both Vδ1 and Vδ2 γδ T cells are implicated to have immunotherapeutic potentials for cancers, but the detailed elucidation of the distinct characteristics of 2 populations will be required to enhance the immunotherapeutic potential of γδ T cells. Here, we summarize recent progress regarding cancer immunology of human γδ T cells, including their development, heterogeneity, and plasticity, the putative mechanisms underlying ligand recognition and activation, and their dual effects on tumor progression in the tumor microenvironment.
Allergy and Immunology ; Communicable Diseases ; Cytokines ; Homeostasis ; Humans ; Interleukin-17 ; Ligands ; Lymphocytes ; Mevalonic Acid ; Plastics ; Population Characteristics ; Protein C ; Receptors, Antigen, T-Cell, gamma-delta ; Receptors, Growth Factor ; T-Lymphocyte Subsets ; T-Lymphocytes ; Terpenes ; Tumor Microenvironment

OBJECTIVE: To study the role of gamma-delta T (γδ T) cells and its subsets in the immunopathogenesis of Henoch-Schönlein purpura (HSP) in children, and to provide new ideas for the treatment of HSP in children from the aspect of γδ T cell regulation. METHODS: A total of 33 children with HSP were enrolled as the HSP group, and 21 healthy children were enrolled as the healthy control group. The percentages of γδ T cells and its subsets Vδ1 T and Vδ2 T cells among peripheral blood mononuclear cells (PBMCs) were measured, as well as the apoptosis rate of γδ T cell and plasma level of interleukin-17 (IL-17). RESULTS: Compared with the healthy control group, the HSP group had significantly lower percentages of lymphocytes in PBMCs and Vδ2 T cells in γδ T cells (P<0.05). The HSP group had significantly higher percentage of Vδ1 T cells in γδ T cells and plasma level of IL-17 than the healthy control group. The HSP group had a significantly higher overall apoptosis rate of γδ T cells than the healthy control group (P<0.05), especially early apoptosis. The percentage of Vδ2 T cells was positively correlated with overall apoptosis rate (r=0.615, P<0.05) and was negatively correlated with IL-17 level (r=-0.398, P<0.05). CONCLUSIONS Vδ1/Vδ2 T cell immune imbalance mediated by γδ T cells and over-activation of IL-17 may be involved in the development of HSP, among which the disturbance of immune tolerance induced by Vδ2 T cells plays an important role in the pathophysiology of the disease.
Child ; Humans ; Leukocytes, Mononuclear ; Purpura, Schoenlein-Henoch ; Receptors, Antigen, T-Cell, gamma-delta ; T-Lymphocytes

Objective To investigate the expression and regulation of programmed cell death protein 1 (PD1), B lymphocyte and T lymphocyte attenuator (BTLA) in peripheral blood of patients with non-small cell lung cancer (NSCLC); to examine the correlation of the mRNA levels between PD and BTLA in NSCLC. Methods Flow cytometry was used to detect the expression of PD1 and BTLA on the surfaces of CD8⁺ T cells and γδ⁺ T cells in the peripheral blood samples collected from 32 in-patients with stage IV NSCLC and 30 healthy individuals. We compared the expression of PD1 and BTLA on the surfaces of γδ⁺ T cells in the NSCLC patients with bone metastasis before and after the treatment of zoledronic acid. The correlations of PD1 and BTLA, as well as their ligands were analyzed using Pearson correlation analysis with the cBioPortal data platform. Results The frequency of PD1 on the surfaces of CD8⁺ T cells was significantly higher than that of the γδT cells in both healthy controls (t=2.324, P=0.024) and NSCLC patients（t=2.498, P=0.015). The frequency of PD1 on CD8⁺ T cells, rather than on γδ⁺ T cells, was significantly upregulated in advanced NSCLC patients compared with that in healthy controls (t=4.829, P<0.001). The PD1⁺ BTLA⁺γδT cells of the healthy controls were significantly lower than that of the NSCLC patients (t=2.422, P=0.0185). No differences in percentage of PD1⁺γδ⁺ and BTLA⁺γδ⁺ T cells were observed in 7 NSCLC patients with bone metastasis before and after zoledronic acid treatment. PD1 was positively correlated with BTLA in both lung adenocarcinoma (r=0.54; P<0.05) and lung squamous cell carcinoma (r=0.78; P<0.05). Conclusions The upregulation of co-inhibitory molecules occurs on the surfaces of both CD8⁺ T cells and γδT cells in advanced NSCLC, suggesting that these molecules were involved in regulating the inactivation of CD8⁺ T cells and γδ⁺ T cells, immune escape and tumor invasion.
Bone Neoplasms/secondary* ; CD8-Positive T-Lymphocytes ; Carcinoma, Non-Small-Cell Lung/immunology* ; Case-Control Studies ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Ligands ; Lung Neoplasms/immunology* ; Lymphocyte Subsets/immunology* ; Male ; Middle Aged ; Programmed Cell Death 1 Receptor/metabolism* ; RNA, Messenger/metabolism* ; Receptors, Antigen, T-Cell, gamma-delta ; Receptors, Immunologic/metabolism*

Anemia, Aplastic ; Antigens, CD ; CD8-Positive T-Lymphocytes ; Humans ; Immunophenotyping ; Leukemia, Large Granular Lymphocytic ; Receptors, Antigen, T-Cell, gamma-delta

OBJECTIVETo investigate the percentages of peripheral blood &gamma;&delta; T cells and regulatory T cells (Treg) and the expression of associated cytokines, interleukin 17 (IL-17) and transforming growth factor-β1 (TGF-β1), in infants with human cytomegalovirus (HCMV) infection.

METHODSTwenty-two infants with HCMV infection (HCMV group) and 22 healthy infants who underwent physical examination (control group) were enrolled in this study. The percentages of peripheral blood &gamma;&delta; T cells and Treg cells were determined by flow cytometry. The levels of IL-17 and TGF-β1 in plasma were measured using ELISA.

RESULTSCompared with the control group, the HCMV group had significantly higher percentage of &gamma;&delta; T cells and IL-17 level (P<0.01) and significantly lower percentage of Treg cells and TGF-β1 level (P<0.01). In the HCMV group, the percentage of &gamma;&delta; T cells was negatively correlated with the percentage of Treg cells and TGF-β1 level (P<0.05), but positively correlated with IL-17 level (P<0.05); the percentage of Treg cells was positively correlated with TGF-β1 level (P<0.05), but negatively correlated with IL-17 level (P<0.05); there was no correlation between IL-17 level and TGF-β1 level (P>0.05).

CONCLUSIONSThere is an imbalance between &gamma;&delta; T cells and Treg cells in the peripheral blood of infants with HCMV infection, and &gamma;&delta; T cells may be involved in the secretion of IL-17.

Cytokines ; blood ; Cytomegalovirus Infections ; immunology ; Female ; Humans ; Infant ; Interleukin-17 ; blood ; Male ; Receptors, Antigen, T-Cell, gamma-delta ; analysis ; T-Lymphocytes, Regulatory ; immunology ; Transforming Growth Factor beta1 ; blood

γδ T cells are abundant in the gut mucosa and play an important role in adaptive immunity as well as innate immunity. Although γδ T cells are supposed to be associated with the enhancement of Ab production, the status of γδ T cells, particularly in the synthesis of IgA isotype, remains unclear. We compared Ig expression in T cell receptor delta chain deficient (TCRδ⁻/⁻) mice with wild-type mice. The amount of IgA in fecal pellets was substantially elevated in TCRδ⁻/⁻ mice. This was paralleled by an increase in surface IgA expression and total IgA production by Peyer's patches (PPs) and mesenteric lymph node (MLN) cells. Likewise, the TCRδ⁻/⁻ mice produced much higher levels of serum IgA isotype. Here, surface IgA expression and number of IgA secreting cells were also elevated in the culture of spleen and bone marrow (BM) B cells. Germ-line α transcript, an indicator of IgA class switch recombination, higher in PP and MLN B cells from TCRδ⁻/⁻ mice, while it was not seen in inactivated B cells. Nevertheless, the frequency of IgA+ B cells was much higher in the spleen from TCRδ⁻/⁻ mice. These results suggest that γδ T cells control the early phase of B cells, in order to prevent unnecessary IgA isotype switching. Furthermore, this regulatory role of γδ T cells had lasting effects on the long-lived IgA-producing plasma cells in the BM.
Adaptive Immunity ; Animals ; B-Lymphocytes* ; Bone Marrow ; Immunity, Innate ; Immunoglobulin A* ; Immunoglobulin Class Switching* ; Lymph Nodes ; Mice ; Mucous Membrane ; Peyer's Patches ; Plasma Cells ; Receptors, Antigen, T-Cell, gamma-delta ; Recombination, Genetic ; Spleen ; T-Lymphocytes*

No abstract available.
Child, Preschool ; Female ; Flow Cytometry ; Humans ; Hydroa Vacciniforme/*diagnosis/pathology ; Immunophenotyping ; Lymphocytosis/complications ; Lymphoma/*diagnosis ; Receptors, Antigen, T-Cell, gamma-delta/genetics/*metabolism ; STAT3 Transcription Factor/genetics/metabolism ; Sequence Analysis, DNA ; Skin/metabolism ; T-Lymphocytes/*metabolism