γδ T cells in infection and autoimmunity

Determination of the molecular mechanism by which macrophages and γδ-T cells contribute to ZOL-induced ONJ

OBJECTIVE

This study aims to explore the molecular mechanism of macrophages and γδ-T cells in the ZOL drug-induced osteonecrosis of jaws based on the IFN-γ involved osteoblast differentiation signaling pathway.

RESULTS

The number and apoptotic rate of CD11b+Gr1hi cells and γδ-T cells in the ONJ group were significantly higher. The TNF-α, IL-1β, IFN-γ, CCL3, CCL4, IL-12 and IL-13 levels were significantly higher in the ONJ group. The expression of CTSK and FGFR3 was lower in the ONJ group, but was higher in the NF-κB and ERBB2IP group.

CONCLUSION

The proliferation of macrophages and γδ-T cells promote the inflammation in ZOL-induced jaw necrosis.

METHODS

A total of 20 patients with osteonecrosis of the jaw from January 2016 to March 2018 were collected and assigned into the observation group, while 20 healthy subjects were assigned into the control group. Furthermore, 40 SD rats were selected and assigned into observation group, while 10 non-treatment SD rats were selected and assigned as controls. The distribution and proportion of CD11b+Gr1hi cells and γδ-T cells in the necrotic tissues of the jaw were analyzed. Then, the TNF-α, IL-1β, IFN-γ, CCL3, CCL4, IL-12 and IL-13 levels were measured. Afterwards, the expression of CTSK, FGFR3, NF-κB and ERBB2IP in the necrotic tissues of the jaw in the animal models were analyzed.

Association between peripheral γδ T cell subsets and disease progression of severe fever with thrombocytopenia syndrome virus infection

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne infectious disease caused by SFTS virus. The cellular immune responses during SFTS virus infection have not been fully understood. This study examined the association between circulating γδ T cell subsets and clinical outcome of SFTS patients from China. A total of 101 hospitalized SFTS patients and 28 healthy controls were enrolled. Peripheral blood was collected, and lymphocyte subgroups and γδ T cell frequencies were evaluated by flow cytometry analysis. Their association with patients' outcome was also investigated. Starting from Week 1, the Vδ1 cells of patients were increased to significantly higher level at Month 3 after disease onset than the controls (P < 0.05), followed by a decrease to the normal level in Year 1. In contrast, the Vδ2 cells displayed significant lower level than the controls from Week 2 to Year 1. On Week 2, the Vδ2 cells demonstrated a significant decrease in the severe patients than both the mild and controls (P < 0.05). The adverse disease progression is accompanied by the reduction of Vδ2 cells, suggesting the key role of Vδ2 cells in the disease progression.

Age dependent differences in the kinetics of γδ T cells after influenza vaccination

Immunosenescence is a hallmark of the aging immune system and is considered the main cause of a reduced vaccine efficacy in the elderly. Although γδ T cells can become activated by recombinant influenza hemagglutinin, their age-related immunocompetence during a virus-induced immune response has so far not been investigated. In this study we evaluate the kinetics of γδ T cells after vaccination with the trivalent 2011/2012 northern hemisphere seasonal influenza vaccine. We applied multi-parametric flow cytometry to a cohort of 21 young (19-30 years) and 23 elderly (53-67 years) healthy individuals. Activated and proliferating γδ T cells, as identified by CD38 and Ki67 expression, were quantified on the days 0, 3, 7, 10, 14, 17, and 21. We observed a significantly lower number of activated and proliferating γδ T cells at baseline and following vaccination in elderly as compared to young individuals. The kinetics changes of activated γδ T cells were much stronger in the young, while corresponding changes in the elderly occurred slower. In addition, we observed an association between day 21 HAI titers of influenza A and the frequencies of Ki67+ γδ T cells at day 7 in the young. In conclusion, aging induces alterations of the γδ T cell response that might have negative implications for vaccination efficacy.

Human γδT-cell subsets and their involvement in tumor immunity

γδT cells are a conserved population of innate lymphocytes with diverse structural and functional heterogeneity that participate in various immune responses during tumor progression. γδT cells perform potent immunosurveillance by exerting direct cytotoxicity, strong cytokine production and indirect antitumor immune responses. However, certain γδT-cell subsets also contribute to tumor progression by facilitating cancer-related inflammation and immunosuppression. Here, we review recent observations regarding the antitumor and protumor roles of major structural and functional subsets of human γδT cells, describing how these subsets are activated and polarized, and how these events relate to subsequent function in tumor immunity. These studies provide insights into the manipulation of γδT-cell function to facilitate more targeted approaches for tumor therapy.

The double-edge role of B cells in mediating antitumor T-cell immunity: Pharmacological strategies for cancer immunotherapy

Emerging evidence reveals the controversial role of B cells in antitumor immunity, but the underlying mechanisms have to be explored. Three latest articles published in the issue 521 of Nature in 2015 reconfirmed the puzzling topic and put forward some explanations of how B cells regulate antitumor T-cell responses both positively and negatively. This paper attempts to demonstrate that different B-cell subpopulations have distinct immunological properties and that they are involved in either antitumor responses or immunosuppression. Recent studies supporting the positive and negative roles of B cells in tumor development were summarized comprehensively. Several specific B-cell subpopulations, such as IgG(+), IgA(+), IL-10(+), and regulatory B cells, were described in detail. The mechanisms underlying the controversial B-cell effects were mainly attributed to different B-cell subpopulations, different B-cell-derived cytokines, direct B cell-T cell interaction, different cancer categories, and different malignant stages, and the immunological interaction between B cells and T cells is mediated by dendritic cells. Promising B-cell-based antitumor strategies were proposed and novel B-cell regulators were summarized to present interesting therapeutic targets. Future investigations are needed to make sure that B-cell-based pharmacological strategies benefit cancer immunotherapy substantially.