Increased expression of herpesvirus entry mediator in 1,25-dihydroxyvitamin D3-treated mouse bone marrow-derived dendritic cells promotes the generation of CD4+CD25+Foxp3+ regulatory T cells

Retinoic acid signaling in development and differentiation commitment and its regulatory topology

Retinoic acid (RA), the derivative of vitamin A/retinol, is a signaling molecule with important implications in health and disease. It is a well-known developmental morphogen that functions mainly through the transcriptional activity of nuclear RA receptors (RARs) and, uncommonly, through other nuclear receptors, including peroxisome proliferator-activated receptors. Intracellular RA is under spatiotemporally fine-tuned regulation by synthesis and degradation processes catalyzed by retinaldehyde dehydrogenases and P450 family enzymes, respectively. In addition to dictating the transcription architecture, RA also impinges on cell functioning through non-genomic mechanisms independent of RAR transcriptional activity. Although RA-based differentiation therapy has achieved impressive success in the treatment of hematologic malignancies, RA also has pro-tumor activity. Here, we highlight the relevance of RA signaling in cell-fate determination, neurogenesis, visual function, inflammatory responses and gametogenesis commitment. Genetic and post-translational modifications of RAR are also discussed. A better understanding of RA signaling will foster the development of precision medicine to improve the defects caused by deregulated RA signaling.

Role of Vitamin D in Head and Neck Cancer-Immune Function, Anti-Tumour Effect, and Its Impact on Patient Prognosis

Head and neck squamous cell carcinoma (HNSCC) describes a heterogeneous group of human neoplasms of the head and neck with high rates of morbidity and mortality, constituting about 3% of all cancers and ~1.5% of all cancer deaths. HNSCC constituted the seventh most prevalent human malignancy and the most common human cancer in the world in 2020, according to multi-population observations conducted by the GLOBOCAN group. Since approximately 60-70% of patients present with stage III/IV neoplastic disease, HNSCC is still one of the leading causes of death in cancer patients worldwide, with an overall survival rate that is too low, not exceeding 40-60% of these patients. Despite the application of newer surgical techniques and the implementation of modern combined oncological treatment, the disease often follows a fatal course due to frequent nodal metastases and local neoplastic recurrences. The role of micronutrients in the initiation, development, and progression of HNSCC has been the subject of considerable research. Of particular interest has been vitamin D, the pleiotropic biologically active fat-soluble family of secosteroids (vitamin-D-like steroids), which constitutes a key regulator of bone, calcium, and phosphate homeostasis, as well as carcinogenesis and the further development of various neoplasms. Considerable evidence suggests that vitamin D plays a key role in cellular proliferation, angiogenesis, immunity, and cellular metabolism. A number of basic science, clinical, and epidemiological studies indicate that vitamin D has multidirectional biological effects and influences anti-cancer intracellular mechanisms and cancer risk, and that vitamin D dietary supplements have various prophylactic benefits. In the 20th century, it was reported that vitamin D may play various roles in the protection and regulation of normal cellular phenotypes and in cancer prevention and adjunctive therapy in various human neoplasms, including HNSCC, by regulating a number of intracellular mechanisms, including control of tumour cell expansion and differentiation, apoptosis, intercellular interactions, angio- and lymphogenesis, immune function, and tumour invasion. These regulatory properties mainly occur indirectly via epigenetic and transcriptional changes regulating the function of transcription factors, chromatin modifiers, non-coding RNA (ncRNAs), and microRNAs (miRs) through protein-protein interactions and signalling pathways. In this way, calcitriol enhances intercellular communication in cancer biology, restores the connection with the extracellular matrix, and promotes the epithelial phenotype; it thus counteracts the tumour-associated detachment from the extracellular matrix and inhibits the formation of metastases. Furthermore, the confirmation that the vitamin D receptor (VDR) is present in many human tissues confirmed the physiopathological significance of vitamin D in various human tumours. Recent studies indicate quantitative associations between exposure to vitamin D and the incidence of HNC, i.e., cancer risk assessment included circulating calcidiol plasma/serum concentrations, vitamin D intake, the presence of the VDR gene polymorphism, and genes involved in the vitamin D metabolism pathway. Moreover, the chemopreventive efficacy of vitamin D in precancerous lesions of the head and neck and their role as predictors of mortality, survival, and recurrence of head and neck cancer are also widely discussed. As such, it may be considered a promising potential anti-cancer agent for developing innovative methods of targeted therapy. The proposed review discusses in detail the mechanisms regulating the relationship between vitamin D and HNSCC. It also provides an overview of the current literature, including key opinion-forming systematic reviews as well as epidemiological, prospective, longitudinal, cross-sectional, and interventional studies based on in vitro and animal models of HNSCC, all of which are accessible via the PubMed/Medline/EMBASE/Cochrane Library databases. This article presents the data in line with increasing clinical credibility.

Nutrition, Immunosenescence, and Infectious Disease: An Overview of the Scientific Evidence on Micronutrients and on Modulation of the Gut Microbiota

The immune system is key to host defense against pathogenic organisms. Aging is associated with changes in the immune system, with a decline in protective components (immunosenescence), increasing susceptibility to infectious disease, and a chronic elevation in low-grade inflammation (inflammaging), increasing the risk of multiple noncommunicable diseases. Nutrition is a determinant of immune cell function and of the gut microbiota. In turn, the gut microbiota shapes and controls the immune and inflammatory responses. Many older people show changes in the gut microbiota. Age-related changes in immune competence, low-grade inflammation, and gut dysbiosis may be interlinked and may relate, at least in part, to age-related changes in nutrition. A number of micronutrients (vitamins C, D, and E and zinc and selenium) play roles in supporting the function of many immune cell types. Some trials report that providing these micronutrients as individual supplements can reverse immune deficits in older people and/or in those with insufficient intakes. There is inconsistent evidence that this will reduce the risk or severity of infections including respiratory infections. Probiotic, prebiotic, or synbiotic strategies that modulate the gut microbiota, especially by promoting the colonization of lactobacilli and bifidobacteria, have been demonstrated to modulate some immune and inflammatory biomarkers in older people and, in some cases, to reduce the risk and severity of gastrointestinal and respiratory infections, although, again, the evidence is inconsistent. Further research with well-designed and well-powered trials in at-risk older populations is required to be more certain about the role of micronutrients and of strategies that modify the gut microbiota-host relationship in protecting against infection, especially respiratory infection.

Calcitriol and Retinoic acid antagonize each other to suppress the production of IL-9 by Th9 cells

Distinct T helper cells, including Th9 cells help maintain homeostasis in the immune system. Vitamins play pivotal role in the immune system through many mechanisms, including regulating the differentiation of T helper cells. Calcitriol (1,25-dihydroxyvitamin D3) and retinoic acid possess hormone-like properties and are the bioactive metabolites of vitamin D and A, respectively, that signal through heterodimers containing the common retinoid X receptor. In contrast to individual treatment with the vitamins that significantly attenuates IL-9 production from Th9 cells, Th9 cells treated with both vitamins demonstrated IL-9 production similar to untreated Th9 cells. This is associated with reciprocal expression of PU.1 and Foxp3. While the recruitment of PU.1 was significantly impaired to the Il9 gene in the presence of calcitriol or retinoic acid in Th9 cells, addition of both vitamins together increased the recruitment of PU.1 to the Il9 gene. Calcitriol and retinoic acid together impaired the recruitment of HDAC1 to the Il9 gene without impacting Gcn5 recruitment. Importantly, retinoic acid negated the effect of calcitriol and impaired the binding of VDR on the Il9 gene by dampened VDR-RXR formation. Collectively, our data show that calcitriol and retinoic acid antagonize each other to regulate the differentiation of Th9 cells.

GRAS-microparticle microarrays identify dendritic cell tolerogenic marker-inducing formulations

Microarrays, miniaturized platforms used for high-content studies, provide potential advantages over traditional in vitro investigation in terms of time, cost, and parallel analyses. Recently, microarrays have been leveraged to investigate immune cell biology by providing a platform with which to systematically investigate the effects of various agents on a wide variety of cellular processes, including those giving rise to immune regulation for application toward curtailing autoimmunity. A specific embodiment incorporates dendritic cells cultured on microarrays containing biodegradable microparticles. Such an approach allows immune cell and microparticle co-localization and release of compounds on small, isolated populations of cells, enabling a quick, convenient method to quantify a variety of cellular responses in parallel. In this study, the microparticle microarray platform was utilized to investigate a small library of sixteen generally regarded as safe (GRAS) compounds (ascorbic acid, aspirin, capsaicin, celastrol, curcumin, epigallocatechin-3-gallate, ergosterol, hemin, hydrocortisone, indomethacin, menadione, naproxen, resveratrol, retinoic acid, α-tocopherol, vitamin D3) for their ability to induce suppressive phenotypes in murine dendritic cells. Two complementary tolerogenic index ranking systems were proposed to summarize dendritic cell responses and suggested several lead compounds (celastrol, ergosterol, vitamin D3) and two secondary compounds (hemin, capsaicin), which warrant further investigation for applications toward suppression and tolerance.

The immunoregulatory axis (programmed death-1/programmed death ligand-1) on CD4+ T cells in lupus nephritis: association with vitamin D and chemokine C-X-C motif ligand 12

Lupus nephritis (LN) is one of the most serious complications of systemic lupus erythematosus (SLE). Multiple immunomodulatory mechanisms contribute to the pathogenesis of LN. A deep understanding of the immunopathogenesis of LN is essential to identify optimal molecular targets, as most immunotherapeutic algorithms are still based on unselective drugs. The study aimed to elucidate the possible association of vitamin D deficiency with the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) axis and inflammatory response in patients with LN, as well as the relationship between the PD-1/PD-L1 axis and chemokine C-X-C motif ligand 12 (CXCL12). Flow cytometry was used to determine the frequencies of CD279 (PD-1) and CD274 (PD-L1) in the peripheral CD3+CD4+ cell population of persons with LN. Furthermore, ELISA was used to detect serum CXCL12 and vitamin D concentrations. A distinct decrease of PD-1 and a significant increase of PD-L1 was demonstrated in patients with LN compared with either SLE patients with no LN or healthy controls. The PD-1/PD-L1 axis was negatively correlated with different disease parameters. Vitamin D deficiency and insufficiency were more prevalent in patients with LN than in controls, being significantly associated with disease activity and inversely associated with the PD-1/PD-L1 expression. Moreover, CXCL12 was negatively correlated with the PD-1/PD-L1 axis and vitamin D concentration. The findings suggest an involvement of the PD-1/PD-L1 axis in lupus nephritis, which might serve as a potential highly selective therapeutic target that is more effective but less toxic. In addition, restoring adequate vitamin D levels in lupus nephritis could be a possible simple measure to control inflammatory immune responses.

Dendritic Cells Transfected with MHC Antigenic Determinants of CBA Mice Induce Antigen-Specific Tolerance in C57Bl/6 Mice

Background

Nonspecific immunosuppressive therapy for graft rejection and graft-versus-host disease (GVHD) is often accompanied by severe side effects such as opportunistic infections and cancers. Several approaches have been developed to suppress transplantation reactions using tolerogenic cells, including induction of FoxP3⁺ Tregs with antigen-loaded dendritic cells (DCs) and induction of CD4⁺IL-10⁺ cells with interleukin IL-10-producing DCs. Here, we assessed the effectiveness of both approaches in the suppression of graft rejection and GVHD.

Methods

IL-10-producing DCs were generated by the transfection of DCs with DNA constructs encoding mouse IL-10. Antigen-loaded DCs from C57BL/6 mice were generated by transfection with DNA constructs encoding antigenic determinants from the H2 locus of CBA mice which differ from the homologous antigenic determinants of C57BL/6 mice.

Results

We found that both IL-10-producing DCs and antigen-loaded immature DCs could suppress graft rejection and GVHD but through distinct nonspecific and antigen-specific mechanisms, respectively. Discussion. We provide data that the novel approach for DCs antigen loading using DNA constructs encoding distinct homologous determinants derived from major histocompatibility complex genes is effective in antigen-specific suppression of transplantation reactions. Such an approach eliminates the necessity of donor material use and may be useful in immunosuppressive therapy side effects prevention.

miRNA-5119 regulates immune checkpoints in dendritic cells to enhance breast cancer immunotherapy

Dendritic cell (DC) based immunotherapy is a promising approach to clinical cancer treatment. miRNAs are a class of small non-coding RNA molecules that bind to RNAs to mediate multiple events which are important in diverse biological processes. miRNA mimics and antagomirs may be potent agents to enhance DC-based immunotherapy against cancers. miRNA array analysis was used to identify a representative miR-5119 potentially regulating PD-L1 in DCs. We evaluated levels of ligands of immune cell inhibitory receptors (IRs) and miR-5119 in DCs from immunocompetent mouse breast tumor-bearing mice, and examined the molecular targets of miR-5119. We report that miRNA-5119 was downregulated in spleen DCs from mouse breast cancer-bearing mice. In silico analysis and qPCR data showed that miRNA-5119 targeted mRNAs encoding multiple negative immune regulatory molecules, including ligands of IRs such as PD-L1 and IDO2. DCs engineered to express a miR-5119 mimic downregulated PD-L1 and prevented T cell exhaustion in mice with breast cancer homografts. Moreover, miR-5119 mimic-engineered DCs effectively restored function to exhausted CD8⁺ T cells in vitro and in vivo, resulting in robust anti-tumor cell immune response, upregulated cytokine production, reduced T cell apoptosis, and exhaustion. Treatment of 4T1 breast tumor-bearing mice with miR-5119 mimic-engineered DC vaccine reduced T cell exhaustion and suppressed mouse breast tumor homograft growth. This study provides evidence supporting a novel therapeutic approach using miRNA-5119 mimic-engineered DC vaccines to regulate inhibitory receptors and enhance anti-tumor immune response in a mouse model of breast cancer. miRNA/DC-based immunotherapy has potential for advancement to the clinic as a new strategy for DC-based anti-breast cancer immunotherapy.

Micronutrients in autoimmune diseases: possible therapeutic benefits of zinc and vitamin D

A functional immune system is essential for healthy life. This is achieved by the coordinate activation and interaction of different immune cells. One should be aware that activation of the immune response is as important as its deactivation when the pathogens are cleared, as otherwise host tissue can be damaged up to life-threatening levels. Autoimmune diseases (AID) represent a phenomenon of immune cells attacking host cells and tissue. Five to eight percent of the world's population are currently affected by 80-100 AID. In recent years, the incidence has been constantly increasing, reaching alarmingly high numbers particularly for type 1 diabetes mellitus, Crohn's disease, rheumatoid arthritis, Sjogren's syndrome and multiple sclerosis. This indicates a higher societal burden of AID for the future. This article provides an overview of general concepts of triggers and underlying mechanisms leading to self-destruction. Lately, several original concepts of disease etiology were revised, and there is a variety of hypotheses on triggers, underlying mechanisms and preventive actions. This article concentrates on the importance of nutrition, especially zinc and vitamin D, for balancing the immune function. Homespun nutritional remedies seem to reenter today's therapeutic strategies. Current treatment approaches are largely symptomatic or suppress the immune system. However, recent studies reveal significant benefits of nutrition-related therapeutic approaches including prevention and treatment of established disease, which offer a cost-efficient and trigger-unspecific alternative addressing balancing rather than suppression of the immune system. Zinc and vitamin D are currently the best studied and most promising candidates for therapeutic intervention.

BTLA-HVEM Checkpoint Axis Regulates Hepatic Homeostasis and Inflammation in a ConA-Induced Hepatitis Model in Zebrafish

The BTLA-HVEM checkpoint axis plays extensive roles in immunomodulation and diseases, including cancer and autoimmune disorders. However, the functions of this checkpoint axis in hepatitis remain limited. In this study, we explored the regulatory role of the Btla-Hvem axis in a ConA-induced hepatitis model in zebrafish. Results showed that Btla and Hvem were differentially expressed on intrahepatic Cd8⁺ T cells and hepatocytes. Knockdown of Btla or Hvem significantly promoted hepatic inflammation. Btla was highly expressed in Cd8⁺ T cells in healthy liver but was downregulated in inflamed liver, as evidenced by a disparate proportion of Cd8⁺Btla⁺ and Cd8⁺Btla^- T cells in individuals without or with ConA stimulation. Cd8⁺Btla⁺ T cells showed minimal cytotoxicity to hepatocytes, whereas Cd8⁺Btla^- T cells were strongly reactive. The depletion of Cd8⁺Btla^- T cells reduced hepatitis, whereas their transfer enhanced hepatic inflammation. These observations indicate that Btla endowed Cd8⁺Btla⁺ T cells with self-tolerance, thereby preventing them from attacking hepatocytes. Btla downregulation deprived this tolerization. Mechanistically, Btla-Hvem interaction contributed to Cd8⁺Btla⁺ T cell tolerization, which was impaired by Hvem knockdown but rescued by soluble Hvem protein administration. Notably, Light was markedly upregulated on Cd8⁺Btla^- T cells, accompanied by the transition of Cd8⁺Btla⁺Light^- to Cd8⁺Btla^-Light⁺ T cells during hepatitis, which could be modulated by Cd4⁺ T cells. Light blockade attenuated hepatitis, thereby suggesting the positive role of Light in hepatic inflammation. These findings provide insights into a previously unrecognized Btla-Hvem-Light regulatory network in hepatic homeostasis and inflammation, thus adding a new potential therapeutic intervention for hepatitis.

Searching for the Transcriptomic Signature of Immune Tolerance Induction-Biomarkers of Safety and Functionality for Tolerogenic Dendritic Cells and Regulatory Macrophages

The last years have witnessed a breakthrough in the development of cell-based tolerance-inducing cell therapies for the treatment of autoimmune diseases and solid-organ transplantation. Indeed, the use of tolerogenic dendritic cells (tolDC) and regulatory macrophages (Mreg) is currently being tested in Phase I and Phase II clinical trials worldwide, with the aim of finding an effective therapy able to abrogate the inflammatory processes causing these pathologies without compromising the protective immunity of the patients. However, there exists a wide variety of different protocols to generate human tolDC and Mreg and, consequently, the characteristics of each product are heterogeneous. For this reason, the identification of biomarkers able to define their functionality (tolerogenicity) is of great relevance, on the one hand, to guarantee the safety of tolDC and Mreg before administration and, on the other hand, to compare the results between different cell products and laboratories. In this article, we perform an exhaustive review of protocols generating human tolDC and Mreg in the literature, aiming to elucidate if there are any common transcriptomic signature or potential biomarkers of tolerogenicity among the different approaches. However, and although several effectors seem to be induced in common in some of the most reported protocols to generate both tolDC or Mreg, the transcriptomic profile of these cellular products strongly varies depending on the approach used to generate them.

Vitamin D increases programmed death receptor-1 expression in Crohn's disease

Background: Vitamin D modulates inflammation in Crohns disease (CD). Programmed death (PD)-1 receptor contributes to the maintenance of immune tolerance. Vitamin D might modulate PD-1 signalling in CD.

Aim: To investigate PD-1 expression on T cell subsets in CD patients treated with vitamin D or placebo.

Methods: We included 40 CD patients who received 1200 IU vitamin D3 for 26 weeks or placebo and eight healthy controls. Peripheral blood mononuclear cells (PBMCs) and plasma were isolated at baseline and week 26. The expressions of PD-1, PD-L1, and surface activation markers were analysed by flow cytometry. Soluble PD-1 plasma levels were measured by ELISA.

Results: PD-1 expression upon T cell stimulation was increased in CD4⁺CD25^+int T cells in vitamin D treated CD patients from 19% (range 10 39%) to 29% (11 79%)(p = 0.03) compared with placebo-treated patients. Vitamin D treatment, but not placebo, decreased the expression of the T cell activation marker CD69 from 42% (31 62%) to 33% (19 - 54%)(p = 0.01). Soluble PD-1 levels were not influenced by vitamin D treatment.

Conclusions: Vitamin D treatment increases CD4⁺CD25^+int T cells ability to up-regulate PD-1 in response to activation and reduces the CD69 expression in CD patients.

A vitamin D receptor agonist converts CD4+ T cells to Foxp3+ regulatory T cells in patients with ulcerative colitis

One of the pathological features of ulcerative colitis (UC) is the dysfunction of immune regulatory T cells (Treg cells); the pathogenesis is unclear and needs to be further investigated. Vitamin D has immune regulatory functions. This study tests a hypothesis that vitamin D receptor (VDR) regulates Treg cell differentiation. Peripheral blood samples were collected from UC patients and healthy subjects. The correlation between VDR expression and T helper (Th)2 cell differentiation in peripheral CD4⁺ T cells was analyzed. We observed that the expression of VDR was lower, the expression of interleukin (IL)-4 was higher, in peripheral CD4⁺ T cells of UC patients than that in healthy controls. Naive CD4⁺ T cells from VDR deficient mice were prone to differentiating into Th2 cells, which could be adjusted by the presence of VDR agonists. The Th2 polarization status in the peripheral CD4⁺ T cells of UC patients could be converted to regulatory T cells in the culture in the presence of VDR agonists. In conclusion, the peripheral Th2 cells in UC patients can be converted to regulatory T cells by VDR agonists in the culture. The results suggest that administration of VDR agonists at proper dosages may improve the immunity of UC patients.

Vitamin D in Autoimmunity: Molecular Mechanisms and Therapeutic Potential

Over the last three decades, it has become clear that the role of vitamin D goes beyond the regulation of calcium homeostasis and bone health. An important extraskeletal effect of vitamin D is the modulation of the immune system. In the context of autoimmune diseases, this is illustrated by correlations of vitamin D status and genetic polymorphisms in the vitamin D receptor with the incidence and severity of the disease. These correlations warrant investigation into the potential use of vitamin D in the treatment of patients with autoimmune diseases. In recent years, several clinical trials have been performed to investigate the therapeutic value of vitamin D in multiple sclerosis, rheumatoid arthritis, Crohn’s disease, type I diabetes, and systemic lupus erythematosus. Additionally, a second angle of investigation has focused on unraveling the molecular pathways used by vitamin D in order to find new potential therapeutic targets. This review will not only provide an overview of the clinical trials that have been performed but also discuss the current knowledge about the molecular mechanisms underlying the immunomodulatory effects of vitamin D and how these advances can be used in the treatment of autoimmune diseases.

Dual antiplasmodial activity of vitamin D3 and its analog, 22-oxacalcitriol, by direct and indirect mechanisms

Recent evidence suggests that 1α,25-dihydroxyvitamin D3 (calcitriol, VD3), the active form of vitamin D (VD), can inhibit the proliferation of microorganisms. In the present study, we conducted in vitro experiments and utilized in vivo murine models to investigate the antimalarial activity of VD3 and its analog, 22-oxacalcitriol (22-OCT), which was designed to cause less hypercalcemia than VD3. VD3 and 22-OCT treatments effectively resolved a Plasmodium chabaudi (Pc) infection in wild-type mice. Reduced parasitemia was observed during the acute phase of infection in the presence of VD3 and 22-OCT, followed by a delayed peak during the chronic stage of infection. Some anti-Pc activity was observed in VD receptor knockout (KO) mice. VD3 and 22-OCT also completely inhibited the proliferation of P. falciparum (Pf) in human red blood cells in vitro. Plasma levels of interferon (IFN)-γ in VD3-treated B10 and B6 mice were lower than those in vehicle-treated animals, and VD3 resolved a Pc infection in IFN-γ-KO mice, which greatly improved survival. These data suggest that the protective effects of VD3 are elicited through an IFN-γ-independent mechanism. Effective antiplasmodial doses of VD3 and 22-OCT resulted in a loss of body weight in mice. This loss in body weight occurred concomitantly with the development of hypercalcemia. Zoledronic acid partially attenuated VD3-induced hypercalcemia and abrogated the antiparasitic effects of VD3. This study highlights a potential therapeutic role for VD3 in the treatment of malarial infections and shows that hypercalcemia is excellent indicator of the antiplasmodial activity of VD3.

Pathogenic Function of Herpesvirus Entry Mediator in Experimental Autoimmune Uveitis by Induction of Th1- and Th17-Type T Cell Responses

Herpesvirus entry mediator (HVEM), a member of the TNFR superfamily, serves as a unique molecular switch to mediate both stimulatory and inhibitory cosignals, depending on its functions as a receptor or ligand interacting with multiple binding partners. In this study, we explored the cosignaling functions of HVEM in experimental autoimmune uveitis (EAU), a mouse model resembling human autoimmune uveitis conditions such as ocular sarcoidosis and Behcet disease. Our studies revealed that EAU severity significantly decreased in HVEM-knockout mice compared with wild-type mice, suggesting that stimulatory cosignals from the HVEM receptor are predominant in EAU. Further studies elucidated that the HVEM cosignal plays an important role in the induction of both Th1- and Th17-type pathogenic T cells in EAU, including differentiation of IL-17-producing αβ(+)γδ(-) conventional CD4(+) T cells. Mice lacking lymphotoxin-like, inducible expression, competes with herpes simplex virus glycoprotein D for HVEM, a receptor expressed by T lymphocytes : LIGHT), B- and T-lymphocyte attenuator (BTLA) or both LIGHT and BTLA are also less susceptible to EAU, indicating that LIGHT-HVEM and BTLA-HVEM interactions, two major molecular pathways mediating HVEM functions, are both important in determining EAU pathogenesis. Finally, blocking HVEM cosignals by antagonistic anti-HVEM Abs ameliorated EAU. Taken together, our studies revealed a novel function of the HVEM cosignaling molecule and its ligands in EAU pathogenesis through the induction of Th1- and Th17-type T cell responses and suggested that HVEM-related molecular pathways can be therapeutic targets in autoimmune uveitis.

Expression of immune checkpoint molecules in endometrial carcinoma

The main obstacle in the development of an effective tumor vaccine is the inherent ability of tumors to evade immune responses. Tumors often use common immune mechanisms and regulators to evade the immune system. The present study aimed to analyze the expression levels of indoleamine 2,3-dioxygenase (IDO), programmed death-ligand (PD-L) 1, PD-L2, B7-H4, galectin-1 and galectin-3 in tissue samples from patients with endometrial carcinoma, in order to detect the immunosuppressive environment of endometrial carcinomas. The levels of IDO, PD-L1, PD-L2 and B7-H4 were analyzed by immunohistochemical methods, and the levels of galectin-1 and galectin-3 in tumor lysates were determined using ELISA. PD-L2 was expressed at low levels in the majority of tumor samples. IDO expression was detected in 38, 63 and 43% of primary endometrial carcinoma, recurrent endometrial carcinoma, and metastatic endometrial carcinoma specimens, respectively. Positive expression rates for PD-L1 were 83% in primary endometrial carcinoma, 68% in recurrent endometrial carcinoma, and 100% in metastatic endometrial carcinoma, whereas B7-H4 expression was detected in 100% of both primary endometrial carcinoma and recurrent endometrial carcinoma samples, and in 96% of metastatic endometrial carcinoma specimens. The expression levels of galectin-1 and galectin-3 were not significantly different between the normal and tumor specimens. The results of the present study suggest that the interaction between PD-1/PD-L1 and B7-H4 may be a potential target for immune intervention in the treatment of endometrial carcinoma. Furthermore, the results may provide the basis for immunosuppressant therapy in the treatment of patients with uterine cancer.

Dendritic cell profile induced by Schistosoma mansoni antigen in cutaneous leishmaniasis patients

The inflammatory response in cutaneous leishmaniasis (CL), although responsible for controlling the infection, is associated with the pathogenesis of disease. Conversely, the immune response induced by S. mansoni antigens is able to prevent immune-mediated diseases. The aim of this study was to evaluate the potential of the S. mansoni Sm29 antigen to change the profile of monocyte-derived dendritic cells (MoDCs) from subjects with cutaneous leishmaniasis (CL) in vitro. Monocytes derived from the peripheral blood mononuclear cells of twelve patients were cultured with GM-CSF and IL-4 for differentiation into dendritic cells and then stimulated with soluble Leishmania antigen (SLA) in the presence or absence of Sm29 antigen. The expression of surface molecules associated with maturation and activation (HLA-DR, CD40, CD83, CD80, and CD86), inflammation (IL-12, TNF), and downregulation (IL-10, IL-10R) was evaluated using flow cytometry. We observed that the frequencies of HLA-DR, CD83, CD80, and CD86 as well as of IL-10 and IL-10R on MoDCs were higher in cultures stimulated with Sm29, compared to the unstimulated cell cultures. Our results indicate that the Sm29 antigen is able to activate regulatory MoDCs in patients with cutaneous leishmaniasis. It might be useful to control the inflammatory process associated with this disease.