Zap70 Regulates TCR-Mediated Zip6 Activation at the Immunological Synapse

Metal-modulated T cell antitumor immunity and emerging metalloimmunotherapy

In recent years, increasing evidence has shown that metals play important roles in both innate and adaptive immunity. An emerging concept of metalloimmunotherapy has been proposed, which may accelerate the development of immunotherapy for cancers. Here, we discuss how metals affect T cell function through different signaling pathways. Metals impact the fate of T cells, including their activation, proliferation, cytotoxicity, and differentiation. Most importantly, metals also participate in mitochondrial operation by regulating energy production and reactive oxygen species homeostasis in T cells. We also identified the metal-based mutual effects between tumor cells and T cells in the tumor microenvironment. Overall, the antitumor effect of T cells can be improved by targeting metal metabolism and metalloimmunotherapy, which will be a step forward in the treatment of cancers.

Translational study of the regulatory mechanism by which immune synapses enhance immune cell function

Immune synapses, which were initially discovered at the interface between antigen-presenting cells (APCs) and T cells, are special structures formed at the contact site between antigen-presenting cells and immune cells and constitute the structural basis for immune cells to kill tumours and synthesise antibodies. Their structures are very similar to those of neural synapses in the nervous system, and they contain different functional structural regions. With the development of cell visualization research, scientists have increasingly conducted in-depth research on immune synapses. At present, it is known that T cells, B cells, and NK cells can form different immune synapses with target cells. Immune synapses formed by different cell subsets as well as CAR-T cells have their own characteristics, mainly in terms of their structure, formation process and regulatory mechanism. Therefore, how to enhance immune cell killing function by enhancing immune synaptic function has long been a research hotspot. At present, the killing function of immune cells can be enhanced by influencing the signalling molecules of immune synapses and the cell microenvironment and modifying the structure of immune synapses. Through a review of the factors affecting immune synapses, we can better explore the target for enhancing immune system function.

SLC39A10 is a key zinc transporter in T cells and its loss mitigates autoimmune disease

Zinc homeostasis plays an essential role in maintaining immune function and is tightly regulated by zinc transporters. We previously reported that the zinc transporter SLC39A10, located in the cell membrane, critically regulates the susceptibility of macrophages to inflammatory stimuli; however, the functional role of SLC39A10 in T cells is currently unknown. Here, we identified two SNPs in SLC39A10 that are associated with inflammatory bowel disease (IBD). We then generated transgenic mice with T cell-specific deletion of Slc39a10 (cKO) and found that its loss not only protects against disease progression in IBD and experimental autoimmune encephalomyelitis (EAE), but also induces massive apoptosis via a p53/p21- and Bcl2-independent process. Mechanistically, we show that Slc39a10 serves as a key zinc importer upon activation of T cell receptor to safeguard DNA replication. Together, these findings provide new mechanistic insights and potential targets for the development of new therapeutic strategies for the treatment and/or prevention of T cell-mediated autoimmune diseases.

The Impact of Selenium Deficiency and T-2 Toxin on Zip6 Expression in Kashin-Beck Disease

This study investigated the expression of Zip6, a gene predominantly located in the placenta, breast, and prostate tissues, in patients with Kashin-Beck disease (KBD). Environmental risk factor models for KBD were developed using low selenium (Se) feeding (with a Se content of 0.02 mg Se/kg in the feed) and exposure to T-2 toxin (200 ng/g*BW/D). Additionally, the study examined the alterations in Se and Zn2+ levels, along with the mRNA and protein expression levels of Zip6 and KBD related genes, including Mtf1, Mmp3, Mmp13, Adamts5, and Col2a1. Differentially expressed genes (DEGs) were examined by transcriptome sequencing to elucidate the mechanism by which Zip6 induces metabolic disorder of the extracellular matrix (ECM), subsequently leading to cartilage injury under the influence of Se deficiency and T-2 toxin. The findings indicated that the expression levels of Zip6 in adult and pediatric KBD chondrocytes were not synchronized. In the animal study, there was a notable increase in the Zn2+ level in the comprehensive exposure (CE) group. Moreover, in both the T-2 exposure (T-2) and CE groups, there was a significant decrease in the expression of Zip6 in each zone, and the expression of Adamts5 in the middle zone exhibited a significant increase (P < 0.05) correlating with varying degrees of cartilage tissue damage in each group. Sequencing results revealed that the significantly up-regulated DEGs in the CE group included Zimz2. This study suggested that Se and T-2 toxin may influence the expression of Zip6, and it investigated the role of Zn2+ in the pathogenesis of KBD, thereby providing a novel scientific foundation for understanding the pathogenesis of KBD.

ZIP transporters-regulated Zn2+ homeostasis: A novel determinant of human diseases

As an essential trace element for organisms, zinc participates in various physiological processes, such as RNA transcription, DNA replication, cell proliferation, and cell differentiation. The destruction of zinc homeostasis is associated with various diseases. Zinc homeostasis is controlled by the cooperative action of zinc transporter proteins that are responsible for the influx and efflux of zinc. Zinc transporter proteins are mainly categorized into two families: Zrt/Irt-like protein (SLC39A/ZIP) family and zinc transporter (SLC30A/ZNT) family. ZIP transporters contain 14 members, namely ZIP1-14, which can be further divided into four subfamilies. Currently, ZIP transporters-regulated zinc homeostasis is one of the research hotspots. Cumulative evidence suggests that ZIP transporters-regulated zinc homeostasis may cause physiological dysfunction and contribute to the onset and progression of diverse diseases, such as cancers, neurological diseases, and cardiovascular diseases. In this review, we initially discuss the structure and distribution of ZIP transporters. Furthermore, we comprehensively review the latest research progress of ZIP transporters-regulated zinc homeostasis in diseases, providing a new perspective into new therapeutic targets for treating related diseases.

Expression of cell surface zinc transporter LIV1 in triple negative breast cancer is an indicator of poor prognosis and therapy failure

Triple negative breast cancers (TNBC) are an aggressive molecular subtype of breast carcinoma (BC) identified by the lack of receptor expression for estrogen, progesterone, & human epidermal growth factor receptor-2. Lack of tangible drug targets warrants further research in TNBC. LIV1, is a zinc (Zn) transporter known to be overexpressed in few cancer types including BCs. Recently, in the United States of America, FDA approved the use of a new drug targeting LIV1, antibody drug conjugate SGN-LIV1A for treatment of TNBC patients. Though LIV1 also has a role in modulating immune cells by its differential transport of Zn, a correlation between the tumor cell expression of LIV1 and immune cell infiltrations were scantily reported. Further adequate baseline data on LIV1 expression in other populations have not been documented. Our objective was to screen a large Indian cohort of TNBC patient samples for LIV1, categorize the immune cell infiltration using CD4/CD8 expression and correlate the findings with therapy outcomes. Further, we also investigated for LIV1 expression in matched samples of primary & secondary tumors; pre & postchemotherapy in TNBC patients. Results showed an elevated expression of LIV1 in TNBC samples as compared to adjacent normal, the mean Q scores being 183.06 ± 6.39 and 120.78 ± 7.37 (p < 0.0001), respectively. Similarly, LIV1 levels were elevated in secondary tumors than primary & in patient samples postchemotherapy as compared to naïve. In the TNBC cohort, using automated method, cell morphology parameters were computed and analysis showed LIV1 levels were elevated in grade 3 TNBC samples presenting with altered cell morphology parameters namely cell size, cell perimeter, & nucleus size. Thus indicating LIV1 expressing TNBC samples portrayed an aggressive phenotype. Finally, TNBC patients with 3+ staining intensity showed poor survival (4.44 year) as compared to patients with 2+ LIV1 expression (5.47 year), emphasizing that LIV1 expression is a poor prognostic factor in TNBC. In conclusion, the study reports elevated expression of LIV1 in a large Indian TNBC cohort; high expression is a poor prognostic factor and correlated with aggressive disease and indicating the need for LIV1 targeted therapies.

Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets

Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.

The changes and potential effects of zinc homeostasis in periodontitis microenvironment

Zinc is a very important and ubiquitous element, which is present in oral environment, daily diet, oral health products, dental restorative materials, and so on. However, there is a lack of attention to the role of both extracellular or intracellular zinc in the progression of periodontitis and periodontal regeneration. This review summarizes the characteristics of immunological microenvironment and host cells function in several key stages of periodontitis progression, and explores the regulatory effect of zinc during this process. We find multiple evidence indicate that zinc may be involved and play a key role in the stages of immune defense, inflammatory response and bone remodeling. Zinc supplementation in an appropriate dose range or regulation of zinc transport proteins can promote periodontal regeneration by either enhancing immune defense or up-regulating local cells proliferation and differentiation functions. Therefore, zinc homeostasis is essential in periodontal remodeling and regeneration. More attention is suggested to be focused on zinc homeostasis regulation and consider it as a potential strategy in the studies on periodontitis treatment, periodontal-guided tissue regeneration, implant material transformation, and so on.

Antiviral activity of zinc against hepatitis viruses: current status and future prospects

Viral hepatitis is a major public health concern globally. World health organization aims at eliminating viral hepatitis as a public health threat by 2030. Among the hepatitis causing viruses, hepatitis B and C are primarily transmitted via contaminated blood. Hepatitis A and E, which gets transmitted primarily via the feco-oral route, are the leading cause of acute viral hepatitis. Although vaccines are available against some of these viruses, new cases continue to be reported. There is an urgent need to devise a potent yet economical antiviral strategy against the hepatitis-causing viruses (denoted as hepatitis viruses) for achieving global elimination of viral hepatitis. Although zinc was known to mankind for a long time (since before Christ era), it was identified as an element in 1746 and its importance for human health was discovered in 1963 by the pioneering work of Dr. Ananda S. Prasad. A series of follow up studies involving zinc supplementation as a therapy demonstrated zinc as an essential element for humans, leading to establishment of a recommended dietary allowance (RDA) of 15 milligram zinc [United States RDA for zinc]. Being an essential component of many cellular enzymes and transcription factors, zinc is vital for growth and homeostasis of most living organisms, including human. Importantly, several studies indicate potent antiviral activity of zinc. Multiple studies have demonstrated antiviral activity of zinc against viruses that cause hepatitis. This article provides a comprehensive overview of the findings on antiviral activity of zinc against hepatitis viruses, discusses the mechanisms underlying the antiviral properties of zinc and summarizes the prospects of harnessing the therapeutic benefit of zinc supplementation therapy in reducing the disease burden due to viral hepatitis.

Zinc transporter LIV1: A promising cell surface target for triple negative breast cancer

Breast cancer is one of the leading causes contributing to the global cancer burden. The triple negative breast cancer (TNBC) molecular subtype accounts for the most aggressive type. Despite progression in therapeutic options and prognosis in breast cancer treatment options, there remains a high rate of distant relapse. With advancements in understanding the role of zinc and zinc carriers in the prognosis and treatment of the disease, the scope of precision treatment/targeted therapy has been expanded. Zinc levels and zinc transporters play a vital role in maintaining cellular homeostasis, tumor surveillance, apoptosis, and immune function. This review focuses on the zinc transporter, LIV1, as an essential target for breast cancer prognosis and emerging treatment options. Previous studies give an insight into the role of LIV1 in fulfilling the most important hallmarks of cancer such as apoptosis, metastasis, invasion, and evading the immune system. Normal tissue expression of LIV1 is limited. Higher expression of LIV1 has been linked to Epithelial-Mesenchymal Transition, histological grade of cancer, and early node metastasis. LIV1 was found to be one of the attractive targets in the therapeutic hunt for TNBCs. TNBCs are an immunogenic breast cancer subtype. As zinc transporters are known to serve as the metabolic gatekeepers of immune cells, this review bridges tumor infiltrating lymphocytes, TNBC and LIV1. In addition, the suitability of LIV1 as an antibody-drug conjugate (Seattle genetics [SGN]-LIV1A) target in TNBC, represents a promising strategy for patients. Early clinical trial results reveal that this novel agent reduces tumor burden by inducing mitotic arrest, immunomodulation, and immunogenic cell death, warranting further investigation of SGN-LIV1A in combination with immuno-oncology agents. Priming the patient's immune response in combination with SGN-LIV1A could eventually change the landscape for the TNBC patient population.