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Background & Aims: Celiac disease could be treated, and potentially cured, by restoring T-cell tolerance to gliadin. We investigated the safety and efficacy of negatively charged 500-nm poly(lactide-co-glycolide) nanoparticles encapsulating gliadin protein (TIMP-GLIA) in 3 mouse models of celiac disease. Uptake of these nanoparticles by antigen-presenting cells was shown to induce immune tolerance in other animal models of autoimmune disease., Methods: We performed studies with C57BL/6; RAG1 -/- (C57BL/6); and HLA-DQ8, huCD4 transgenic Ab0 NOD mice. Mice were given 1 or 2 tail-vein injections of TIMP-GLIA or control nanoparticles. Some mice were given intradermal injections of gliadin in complete Freund's adjuvant (immunization) or of soluble gliadin or ovalbumin (ear challenge). RAG -/- mice were given intraperitoneal injections of CD4 + CD62L - CD44 hi T cells from gliadin-immunized C57BL/6 mice and were fed with an AIN-76A-based diet containing wheat gluten (oral challenge) or without gluten. Spleen or lymph node cells were analyzed in proliferation and cytokine secretion assays or by flow cytometry, RNA sequencing, or real-time quantitative polymerase chain reaction. Serum samples were analyzed by gliadin antibody enzyme-linked immunosorbent assay, and intestinal tissues were analyzed by histology. Human peripheral blood mononuclear cells, or immature dendritic cells derived from human peripheral blood mononuclear cells, were cultured in medium containing TIMP-GLIA, anti-CD3 antibody, or lipopolysaccharide (controls) and analyzed in proliferation and cytokine secretion assays or by flow cytometry. Whole blood or plasma from healthy volunteers was incubated with TIMP-GLIA, and hemolysis, platelet activation and aggregation, and complement activation or coagulation were analyzed., Results: TIMP-GLIA did not increase markers of maturation on cultured human dendritic cells or induce activation of T cells from patients with active or treated celiac disease. In the delayed-type hypersensitivity (model 1), the HLA-DQ8 transgenic (model 2), and the gliadin memory T-cell enteropathy (model 3) models of celiac disease, intravenous injections of TIMP-GLIA significantly decreased gliadin-specific T-cell proliferation (in models 1 and 2), inflammatory cytokine secretion (in models 1, 2, and 3), circulating gliadin-specific IgG/IgG2c (in models 1 and 2), ear swelling (in model 1), gluten-dependent enteropathy (in model 3), and body weight loss (in model 3). In model 1, the effects were shown to be dose dependent. Splenocytes from HLA-DQ8 transgenic mice given TIMP-GLIA nanoparticles, but not control nanoparticles, had increased levels of FOXP3 and gene expression signatures associated with tolerance induction., Conclusions: In mice with gliadin sensitivity, injection of TIMP-GLIA nanoparticles induced unresponsiveness to gliadin and reduced markers of inflammation and enteropathy. This strategy might be developed for the treatment of celiac disease., (Copyright © 2020 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Despite recent progress in the understanding of γδ T cells' roles and functions, their interaction with αβ T cells still remains to be elucidated. In this study, we sought to clarify what precisely endows peripheral Vδ2 + T cells with immunosuppressive function on autologous αβ T cells. We found that negatively freshly isolated Vδ2 + T cells do not exhibit suppressive behavior, even after stimulation with IL-12/IL-18/IL-15 or the sheer contact with butyrophilin-3A1-expressing tumor cell lines (U251 or SK-Mel-28). On the other hand, Vδ2 + T cells positively isolated through TCR crosslinking or after prolonged stimulation with isopentenyl pyrophosphate (IPP) mediate strong inhibitory effects on αβ T cell proliferation. Stimulation with IPP in the presence of IL-15 induces the most robust suppressive phenotype of Vδ2 + T cells. This indicates that Vδ2 + T cells' suppressive activity is dependent on a TCR signal and that the degree of suppression correlates with its strength. Vδ2 + T cell immunosuppression does not correlate with their Foxp3 expression but rather with their PD-L1 protein expression, evidenced by the massive reduction of suppressive activity when using a blocking antibody. In conclusion, pharmacologic stimulation of Vδ2 + T cells via the Vδ2 TCR for activation and expansion induces Vδ2 + T cells' potent killer activity while simultaneously licensing them to suppress αβ T cell responses. Taken together, the study is a further step to understand-in more detail-the suppressive activity of Vδ2 + γδ T cells.

The embryo is a natural allograft and is the only exception to immune rejection, which reflects maternal immune tolerance towards the embryo. However, pregnancy loss is primarily caused by maternal immune rejection of the embryo. The aim of the present study was to explore the effects of combined treatment of programmed death‑ligand 1 (PD‑L1) immunoglobulin (Ig) and CD40‑ligand (CD40L) monoclonal antibody (mAb) on immune tolerance in an abortion‑prone mating model. Mice were divided into the normal, spontaneous abortion, PD‑L1 Ig, CD40L mAb and the PD‑L1 Ig + CD40L mAb groups. On day 14 of gestation, the embryo resorption abortion rates of all the groups was observed. The maternal hypo‑responsiveness to paternal antigens was determined using a mixed lymphocyte response and the splenic CD4+CD25+ T‑cell population, major histocompatibility complex (MHC)‑II+, CD80+ and CD86+ cell populations in pregnant female CBA/J mice were analyzed using flow cytometry. The expression levels of intracellular cytokines in the splenic tissues of pregnant CBA/J female mice were analyzed using western blotting. The PD‑L1 Ig + CD40L group displayed the lowest resorption rate compared with the other groups. A significant decrease in the proliferative response of maternal splenic immunocompetent cells against paternal antigens, and a significant increase in the proliferative response of maternal splenic CD4+CD25+ T cells was observed in the PD‑L1 Ig + CD40L group compared with the spontaneous abortion group. The number of MHC‑II+, CD80+ and CD86+ bone marrow‑derived dendritic cells (DCs) generated by female mice, and the levels of tumor necrosis factor‑α and interferon‑γ in the spleens of female mice were significantly decreased in the PD‑L1 Ig + CD40L mAb group compared with the spontaneous abortion group. By contrast, interleukin‑4 levels were significantly increased in the PD‑L1 Ig + CD40L mAb group compared with the spontaneous abortion group. The results suggested that the administration of PD‑L1 Ig + CD40L mAb on day 4 of gestation, the period of peri‑implantation, may induce paternal antigen‑specific immunotolerance, leading to the embryo resorption rate of the abortion‑prone model being similar to that of the normal pregnancy model. The results indicate that the combined treatment of PD‑L1 Ig and anti‑CD40L mAbs may serve as a potential therapeutic for pregnancy loss.

Proteasome inhibitors significantly improve cancer outcomes, but their use is eventually followed by proteasome inhibitor resistance and relapse. Current understanding of proteasome inhibitor resistance is limited to cell-autonomous mechanisms; whether non-autonomous mechanisms can be implicated in the development of proteasome inhibitor resistance is unclear. Here, we show that proteasome inhibitor tolerance can be transmitted non-autonomously through exosome-mediated intercellular interactions. We revealed that reversible proteasome inhibitor resistance can be transmitted from cells under therapy stress to naïve sensitive cells through exosome-mediated cell cycle arrest and enhanced stemness in mixed-lineage leukemia cells. Integrated multi-omics analysis using the Tied Diffusion through Interacting Events algorithm identified several candidate exosomal proteins that may serve as predictors for proteasome inhibitor resistance and potential therapeutic targets for treating refractory mixed-lineage leukemia. Furthermore, inhibiting the secretion of exosomes is a promising strategy for reversing proteasome inhibitor resistance in vivo, which provides a novel proof of principle for the treatment of other refractory or relapsed cancers., (© 2020 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Dendritic cells (DCs) represent one of the most important biological tools for cellular immunotherapy purposes. There are an increasing number of phase I and II studies, where regulatory or tolerogenic DCs (TolDCs) are utilized as negative vaccines, with the aim of inducing tolerogenic outcomes in patients with various autoimmune or chronic-inflammatory diseases, as well as in transplant settings. The induction of tolerogenic properties in DCs can be achieved by altering their activation state toward expression of immunosuppressive elements and/or by achieving resistance to maturation, which leads to insufficient co-stimulatory signal delivery and inability to efficiently present antigens. In the past, one of the most efficient ways to induce DC tolerance has been the application of selected pharmacological agents which actively induce a tolerogenic transcription program or inhibit major pro-inflammatory transcription factors such as Nf-κB. Important examples include immunosuppressants such as different corticosteroids, vitamin D 3 , rapamycin and others. The quality of TolDCs induced by different approaches is becoming a vital issue and recent evidence suggests substantial heterogeneity between variously-generated TolDCs as evidenced by their transcriptomic profile and function. The possibility of various "flavors" of TolDCs encourages future research in discovery of Tol-DC inducing agents to enrich various ways of DC manipulation. This would enable a broader range of tools to manipulate DC toward specific characteristics desirable in different disease settings. In recent years, several novel small molecules have been identified with the capacity to promote DC tolerogenic characteristics. In this review, we will present and discuss these novel findings and also highlight novel understandings of tolerogenic mechanisms by which DC tolerogenicity is induced by already established agents., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Myeloid derived suppressor cells (MDSC) suppress the ability of cytotoxic T cells to attack and clear tumor cells from the body. The active form of vitamin D, 1,25 dihydroxyvitamin D (1,25(OH) 2 D), regulates myeloid cell biology and previous research showed that in mouse models 1,25(OH) 2 D reduced the tumor level of CD34+ cells, an MDSC precursor, and reduced metastasis. We tested whether MDSC are vitamin D target cells by examining granulocytic- (G-MDSC) and monocytic (M-MDSC) MDSC from tumors, spleen, and bone marrow. Vitamin D receptor (VDR) mRNA levels are low in MDSC from bone marrow and spleen but are 20-fold higher in tumor MDSC. At all sites, M-MDSC have 4-fold higher VDR mRNA expression than G-MDSC. Bone marrow MDSC were induced to differentiate in vitro into tumor MDSC-like cells by treating with IFN-γ, IL-13, and GM-CSF for 48 h. This treatment significantly elevated Arg1 and Nos2 levels, activated the T cell-suppressive function of MDSC, increased VDR expression 50-fold, and made the MDSC responsive to 1,25(OH) 2 D treatment. Importantly, 1,25(OH) 2 D treatment reduced the T cell suppressive capacity of cytokine-induced total MDSC and M-MDSC by ≥70 % and tumor-derived M-MDSC by 30-50 %. Consistent with this finding, VDR deletion (KO) increased T cell suppressive function of in vitro M-MDSC by 30 % and of tumor-derived M-MDSC by 50 % and G-MDSC by 400 %. VDR KO did not alter Nos2 mRNA levels but significantly increased Arg1 mRNA levels in tumor M-MDSC by 100 %. In contrast, 1,25(OH) 2 D treatment reduced nitric oxide production in both in vitro derived M- and G- MDSC. The major finding of this study is that 1,25(OH) 2 D signaling through the VDR decreases the immunosuppressive capability of MDSC. Collectively, our data suggest that activation of vitamin D signaling could be used to suppress MDSC function and release a constraint on T-cell mediated clearance of tumor cells., (Copyright © 2019. Published by Elsevier Ltd.)

Immune response during sepsis is characterized by hyper-inflammation followed by immunosuppression. The crucial role of macrophages is well-known for both septic stages, since they are involved in immune homeostasis and inflammation, their dysfunction being implicated in immunosuppression. The cholinergic anti-inflammatory pathway mediated by macrophage α7 nicotinic acetylcholine receptor (nAChR) represents possible drug target. Although α7 nAChR activation on macrophages reduces the production of proinflammatory cytokines, the role of these receptors in immunological changes at the cellular level is not fully understood. Using α7 nAChR selective agonist PNU 282,987, we investigated the influence of α7 nAChR activation on the expression of cytokines and, for the first time, of the macrophage membrane markers: cluster of differentiation 14 (CD14), human leukocyte antigen-DR (HLA-DR), CD11b, and CD54. Application of PNU 282,987 to THP-1Mϕ (THP-1 derived macrophages) cells led to inward ion currents and Ca 2+ increase in cytoplasm showing the presence of functionally active α7 nAChR. Production of cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-10 was estimated in classically activated macrophages (M1) and treatment with PNU 282,987 diminished IL-10 expression. α7 nAChR activation on THP-1Mϕ, THP-1M1, and monocyte-derived macrophages (MDMs) increased the expression of HLA-DR, CD54, and CD11b molecules, but decreased CD14 receptor expression, these effects being blocked by alpha (α)-bungarotoxin. Thus, PNU 282,987 enhances the macrophage-mediated immunity via α7 nAChR by regulating expression of their membrane receptors and of cytokines, both playing an important role in preventing immunosuppressive states.

Replacement therapy with coagulation factor VIII (FVIII) represents the current clinical treatment for patients affected by hemophilia A (HA). This treatment while effective is, however, hampered by the formation of antibodies which inhibit the activity of infused FVIII in up to 30% of treated patients. Immune tolerance induction (ITI) protocols, which envisage frequent infusions of high doses of FVIII to confront this side effect, dramatically increase the already high costs associated to a patient's therapy and are not always effective in all treated patients. Therefore, there are clear unmet needs that must be addressed in order to improve the outcome of these treatments for HA patients. Taking advantage of preclinical mouse models of hemophilia, several strategies have been proposed in recent years to prevent inhibitor formation and eradicate the pre-existing immunity to FVIII inhibitor positive patients. Herein, we will review some of the most promising strategies developed to avoid and eradicate inhibitors, including the use of immunomodulatory drugs or molecules, oral or transplacental delivery as well as cell and gene therapy approaches. The goal is to improve and potentiate the current ITI protocols and eventually make them obsolete., (Copyright © 2020 Merlin and Follenzi.)

Major abdominal procedures could induce dysfunction in the immune system and lead to postoperative immunosuppression. Sleep dysfunction is associated with impaired immune activity. However, the effects of postoperative sleep dysfunction on postoperative immune function remain unclear. In this study, we found that sleep-restriction (SR) after surgery increased the spleen weight and the percentage of myeloid-derived suppressor cells (MDSCs) in the spleen, and inhibited splenic CD8 + T cells activity, which was via inhibiting subdiaphragmatic vagus nerve (SVN)-mediated trefoil factor 2 (TFF2) expression in the spleen of aged mice. Dexmedetomidine could alleviate SR-induced these changes via modulating gut microbiota, which acted through SVN. Moreover, we showed essential roles of splenic TFF2 in attenuating SR-induced reduced protective ability against Escherichia coli ( E. coli ) pneumonia, increased expression of IL-4 and IL-13 in the lung and M2 polarization of alveolar macrophages (AMs), and decreased phagocytic activity of AMs. Dexmedetomidine improved SR-induced reduced protective ability against E. coli pneumonia via splenic TFF2, and subsequently decreasing IL-4 and IL-13 expression in the lung via modulating gut microbiota/SVN, increasing the compromised phagocytic activity of AMs, and ultimately decreasing M2 polarization of AMs. Taken together, dexmedetomidine-induced increase in splenic TFF2 expresssion could alleviate SR-induced exaggeration of postoperative immunosuppression.

Extracellular cold-inducible RNA-binding protein (eCIRP) is a damage-associated molecular pattern, whose effect on macrophages is not entirely elucidated. Here we identified that eCIRP promotes macrophage endotoxin tolerance. Septic mice had higher serum levels of eCIRP; this was associated with a reduced ex vivo immune response of their splenocytes to LPS. Pretreatment of macrophages with recombinant murine CIRP (rmCIRP) resulted in a tolerance to LPS stimulation as demonstrated by a reduction of TNF-α production. We found that eCIRP increased phosphorylated STAT3 (p-STAT3) in macrophages. A STAT3 inhibitor, Stattic, rescued macrophages from rmCIRP-induced tolerance by restoring the release of TNF-α in response to LPS stimulation. We discovered strong binding affinity between eCIRP and IL-6 receptor (IL-6R) as revealed by Biacore, fluorescence resonance energy transfer (FRET), and their colocalization in macrophages by immunostaining assays. Blockade of IL-6R with its neutralizing Ab inhibited eCIRP-induced p-STAT3 and restored LPS-stimulated TNF-α release in macrophages. Incubation of macrophages with rmCIRP skewed them toward an M2 phenotype, while treatment with anti-IL-6R Ab prevented rmCIRP-induced M2 polarization. Thus, we have demonstrated that eCIRP activates p-STAT3 via a novel receptor, IL-6R, to promote macrophage endotoxin tolerance. Targeting eCIRP appears to be a new therapeutic option to correct immune tolerance in sepsis.

Immune response to therapeutic enzymes poses a detriment to patient safety and treatment outcome. Enzyme replacement therapy (ERT) is a standard therapeutic option for some types of mucopolysaccharidoses, including Morquio A syndrome caused by N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency. Current protocols tolerize patients using cytotoxic immunosuppressives, which can cause adverse effects. Here we show development of tolerance in Morquio A mice via oral delivery of peptide or GALNS for 10 days prior to ERT. Our results show that using an immunodominant peptide (I10) or the complete GALNS enzyme to orally induce tolerance to GALNS prior to ERT resulted in several improvements to ERT in mice: (a) decreased splenocyte proliferation after in vitro GALNS stimulation, (b) modulation of the cytokine secretion profile, (c) decrease in GALNS-specific IgG or IgE in plasma, (d) decreased GAG storage in liver, and (e) fewer circulating immune complexes in plasma. This model could be extrapolated to other lysosomal storage disorders in which immune response hinders ERT.

Apoptotic cells mediate the development of tolerogenic dendritic cells (DC) and thus facilitate induction and maintenance of peripheral tolerance. Following the identification of the evolutionary conserved annexin core domain (Anx) as a specific signal on apoptotic cells which antagonises Toll-like receptor (TLR) signalling, we examined whether the tolerogenic capacity of Anx can be exploited to downregulate antigen-specific immune responses. The treatment of bone marrow-derived dendritic cells (BMDC) with particles harbouring Anx as well as the model antigen ovalbumin (OVA) attenuated the response of OVA-specific OT-II T cells. The co-culture of Anx-particle-treated DC and T cells resulted in an anergy-like phenotype characterized by reduced proliferation and cytokine secretion. Here we demonstrate that the anti-inflammatory effects of Anx which are mediated through DC can be used as a tool to generate a particle-based antigen delivery system that promotes antigen-specific immunosuppression. Such Anx-particles may be a new therapeutic approach for the treatment of autoimmune diseases.

CD28 and CTLA-4 are both important stimulatory receptors for the regulation of T cell activation. Because receptors share common ligands, B7.1 and B7.2, the expression and biological function of CTLA-4 is important for the negative regulation of T cell responses. Therefore, elimination of CTLA-4 can result in the breakdown of immune tolerance and the development of several diseases such as autoimmunity. Inhibitory signals of CTLA-4 suppress T cell responses and protect against autoimmune diseases in many ways. In this review, we summarize the structure, expression and signaling pathway of CTLA-4. We also highlight how CTLA-4 defends against potentially self-reactive T cells. Finally, we discuss how the CTLA-4 regulates a number of autoimmune diseases that indicate manipulation of this inhibitory molecule is a promise as a strategy for the immunotherapy of autoimmune diseases., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Scope: Short-peptide-based enteral nutrition (SPEN) is absorbed more efficiently in patients with severe acute pancreatitis (SAP). More importantly, SPEN decreases SAP-induced enterogenous infection risk. This study aims to investigate whether SPEN alleviates intestinal bacterial translocation in mice with SAP, and the underlying mechanisms., Methods and Results: The SAP model is established after pre-treatment with SPEN or intact-protein-based enteral nutrition. Although there is no improvement in pancreas injury, as evaluated through Hematoxylin-Eosin staining or serum amylase, SPEN obviously attenuates intestinal bacterial translocation after SAP. To unveil the mechanisms, it is found that the intestinal mechanical barrier destroyed by SAP is significantly relieved by SPEN, which presents with recovered ZO-1 expression, mucus layer, and goblet cell function. Additionally, SPEN alleviates local CCR6/CCL20 induced CD11c + dendritic cell infiltration, systemic immunosuppression, and inhibits the secretion of luminal secretory immunoglobulin A. Possibly responsible for SAP-induced mucosal dysfunctions, destroyed intestinal mucosal microcirculation and local hypoxia are largely improved in SAP+SPEN group., Conclusion: SPEN can improve downregulated intestinal mucosal microcirculation secondary to SAP, which may be responsible for mucosal inflammation relief, maintenance of the mechanical barrier and mucosal immunity, the correction of systemic immunosuppression, and play a protective role in defending commensal bacterial translocation after SAP., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Bacterial cell wall component-induced tolerance represents an important protective mechanism during microbial infection. Tolerance induced by the TLR2 agonist bacterial lipoprotein (BLP) has been shown to attenuate the inflammatory response, and simultaneously to augment antimicrobial function, thereby conferring its protection against microbial sepsis. However, the underlying mechanism by which BLP tolerance augments bactericidal activity has not been fully elucidated. Here, we reported that the induction of BLP tolerance in murine macrophages upregulated the expression of Rab20, a membrane trafficking regulator, at both the mRNA and protein levels upon bacterial infection. The knockdown of Rab20 with Rab20 specific siRNA (siRab20) did not affect the phagocytosis of Escherichia coli (E. coli), but substantially impaired the intracellular killing of the ingested E. coli in BLP-tolerized macrophages. Furthermore, Rab20 was associated with GFP-E. coli containing phagosomes, and BLP tolerization resulted in the enhanced maturation of GFP-E. coli-containing phagosomes associated with Rab20 and strong lysosomal acidification. The knockdown of Rab20 substantially diminished lysosome acidification and disturbed the fusion of GFP-E. coli containing phagosomes with lysosomes in BLP-tolerized macrophages. These results demonstrate that Rab20 plays a critical role in BLP tolerization-induced augmentation of bactericidal activity via promoting phagosome maturation and the fusion of bacteria containing phagosomes with lysosomes.

The purpose of this study was to assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and immunogenicity of BOS161721, a humanized immunoglobulin G1 triple mutation (M252Y/S254T/T256E) monoclonal antibody that inhibits interleukin-21 (IL-21) bioactivity. This randomized, single-center, double-blind, placebo-controlled study randomized healthy volunteers 3:1 to single ascending intravenous and subcutaneous doses of BOS161721 (range 1-240 mg) or placebo. BOS161721 and placebo groups had similar rates of adverse events, mostly mild; none led to study discontinuation. There were no clinically significant findings in physical examination, vital signs, or laboratory assessment. In the pooled BOS161721 population, four subjects (8.5%) tested antidrug antibody-positive predose, and seven (14.9%) postdose. Absolute CD4+ lymphocyte count remained normal throughout follow-up. BOS161721 administered subcutaneously was absorbed slowly, with a median time to maximum concentration (T max ) of 144 hours across doses (range 1-15 days) and a mean apparent terminal elimination half-life of 80-87 days for doses ≥ 30 mg. Area under the concentration-time curve from time zero to infinity (AUC 0-inf ) and maximum observed concentration (C max ) were linear across doses > 10 mg. Subcutaneous bioavailability was 64%. Phosphorylated signal transducer and activator of transcription 3 (pSTAT3) decreased dose-dependently with threshold characteristics at doses of ≥ 10 mg. Downregulation in BATF, IL6, LAG3, and SOCS3 genes caused by IL-21 stimulation was reversed dose-dependently. BOS161721 was well-tolerated across doses, suppressed IL-21-induced pSTAT3 dose-dependently, and reversed downregulation of genes critical to tolerance induction and T-cell exhaustion induced by IL-21. Further clinical studies are ongoing in patients with systemic lupus erythematosus, in which IL-21 has a pathogenetic role., (© 2019 Boston Pharmaceuticals. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of the American Society for Clinical Pharmacology and Therapeutics.)

Tumor necrosis factor inhibitors (TNFi) have significantly improved treatment outcome of rheumatic diseases since their incorporation into treatment protocols two decades ago. Nevertheless, a substantial fraction of patients experiences either primary or secondary failure to TNFi due to ineffectiveness of the drug or adverse reactions. Secondary failure and adverse events can be related to the development of anti-drug antibodies (ADA). The earliest studies that reported ADA toward TNFi mainly used drug-sensitive assays. Retrospectively, we recognize this has led to an underestimation of the amount of ADA produced due to drug interference. Drug-tolerant ADA assays also detect ADA in the presence of drug, which has contributed to the currently reported higher incidence of ADA development. Comprehension and awareness of the assay format used for ADA detection is thus essential to interpret ADA measurements correctly. In addition, a concurrent drug level measurement is informative as it may provide insight in the extent of underestimation of ADA levels and improves understanding the clinical consequences of ADA formation. The clinical effects are dependent on the ratio between the amount of drug that is neutralized by ADA and the amount of unbound drug. Pharmacokinetic modeling might be useful in this context. The ADA response generally gives rise to high affinity IgG antibodies, but this response will differ between patients. Some patients will not reach the phase of affinity maturation while others generate an enduring high titer high affinity IgG response. This response can be transient in some patients, indicating a mechanism of tolerance induction or B-cell anergy. In this review several different aspects of the ADA response toward TNFi will be discussed. It will highlight the ADA assays, characteristics and regulation of the ADA response, impact of immunogenicity on the pharmacokinetics of TNFi, clinical implications of ADA formation, and possible mitigation strategies., (Copyright © 2020 Atiqi, Hooijberg, Loeff, Rispens and Wolbink.)

Immune checkpoint inhibition with monoclonal antibodies is becoming increasingly commonplace in cancer medicine, having contributed to a widening of therapeutic options across oncological indications. Disruption of immune tolerance is the key mechanism of action of checkpoint inhibitors and although immune-related adverse events are a typical class effect of these compounds, the relationship between toxicity and response is not fully understood. Awareness and vigilance are paramount in recognizing potentially life-threatening toxicities and managing them in a timely manner. In this review article, we provide an overview of the clinical features, pathological findings and management principles of common immune-related toxicities, attempting to provide mechanistic insight into an increasingly common complication of cancer therapy., (© 2019 John Wiley & Sons Ltd.)

Human chorionic gonadotropin (hCG) can attract regulatory T cells (Tregs) into the fetal-maternal interface regulating maternal immune tolerance in pregnancy. The objective of this study was to investigate whether hCG recruits the Tregs into endometrium by inducing chemokines. The number of Tregs in the endometrium was analyzed by immunohistochemistry. The expression of CCL2 was analyzed in vivo and in vitro with hCG stimulation. CD4 + CD25 + Tregs were isolated from peripheral blood for Tregs migration assay with hCG, CCL2 siRNA and CCR2 antagonist stimulation. Our results showed that the number of endometrial Tregs in RIF patients was significantly decreased (9.4 ± 5.3 vs. 23.1 ± 3.1, P < 0.01), while intrauterine infusion of 2000 IU hCG increased the endometrial Tregs (18.6 ± 9.8 vs. 9.4 ± 5.3, P < 0.05) and CCL2 expression (0.21 ± 0.01 vs. 0.17 ± 0.01, P < 0.01). Horn injecting with 10 IU hCG also increased the endometrial Tregs in pseudopregnant mice (46 ± 16.8 vs. 7 ± 4.3, P < 0.01). Furthermore, the CCL2 protein and mRNA levels were significantly increased in human endometrial stromal cells (hESCs) with the stimulation of hCG. Migration assays showed that hESCs with hCG stimulation promoted Tregs migration (2597 ± 833.2 vs. 1115 ± 670.7, P < 0.05), while the number of migrated Tregs significantly decreased with CCL2 siRNA (1061 ± 105.4 vs. 2598 ± 294.7, P < 0.05) or CCR2 antagonist (356.7 ± 138.8 vs. 2597 ± 833.2, P < 0.05) treatment. In conclusion, intrauterine perfusion of hCG might promote the recruitment of Tregs into endometrium by inducing chemokine CCL2., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Recurrent respiratory papillomatosis (RRP) is characterized by benign exophytic lesions of the respiratory tract caused by the human papillomavirus (HPV), in particular low-risk HPV6 and HPV11. Aggressiveness varies greatly among patients. Surgical excision is the current standard of care for RRP, with adjuvant therapy used when surgery cannot control disease recurrence. Numerous adjuvant therapies have been used to control RRP with some success, but none are curative. Current literature supports a polarization of the adaptive immune response to a T helper type 2 (Th2)-like or T regulatory phenotype, driven by a complex interplay between innate immunity, adaptive immunity and HPV6/11 proteins. Additionally, certain immunogenetic polymorphisms can predispose individuals to an HPV6/11-tolerant microenvironment. As a result, immunomodulatory efforts are being made to restore the host immune system to a more balanced T cell phenotype and clear viral infection. Literature has shown exciting evidence for the role of HPV vaccination with Gardasil or Gardasil-9 as both primary prevention, by decreasing incidence through childhood vaccinations, and secondary prevention, by treating active RRP disease. Multi-institution randomized clinical trials are needed to better assess their efficacy as treatment for active disease. Interestingly, a DNA vaccine has recently shown in-vitro success in generating a more robust CD8 + T cell response. Furthermore, clinical trials for programmed death 1 (PD-1) inhibitors are under investigation for RRP management. Molecular insights into RRP, in particular the interplay between RRP and the immune system, are needed to advance our understanding of this disease and may lead to the identification of immunomodulatory agents to better manage RRP., (© 2019 British Society for Immunology.)

Pregnancy is a kind of natural immune tolerance. Immune factors play an important role in recurrent spontaneous abortion and repeated implantation failure. Salvianolic acid B (SalB) has anti-tumor, anti-inflammatory, anti-oxidation and immunomodulatory functions. However, there are few reports on the relationship between SalB and maternal-fetal immune tolerance. In this study, CBA/J × DBA/2 J mice as a spontaneous abortion mouse model were given SalB. The results showed that the abortion rate was significantly decreased after SalB treatment. The populations of Nkp46 and cytotoxic CD8 + T cells in the placenta of female mice treated with SalB were significantly decreased. The qRT-PCR showed that SalB was able to significantly reduce the expression of pro-inflammatory factors and Toll-like Receptor in the placenta. In addition, SalB was able to increase the area of the labyrinth in the placenta. In conclusion, these findings suggest that SalB is beneficial for the immune-modulation at the maternal-fetal interface in a spontaneous abortion mouse model, resulting in a decrease in the abortion rate. This may encourage new ideas for the treatment of patients with repeated implantation failure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Immune tolerance against alloantigens plays an important role in the success of clinical organ and allogeneic hematopoietic stem cell transplantation. The mechanisms of immune tolerance to alloantigens have gradually been elucidated over time. Although there have been numerous reports to date on the induction of tolerance to alloantigens, the establishment of mixed chimerism is well-known to be crucial in the induction and maintenance of immune tolerance for either of the methods. Since the early 1980s, the murine system of cyclophosphamide (Cy)-induced tolerance has also been examined extensively. The present review focuses on studies conducted on Cy-induced immune tolerance. Clinical data of patients with allogeneic transplantation suggest that the posttransplant Cy method to induce immune tolerance has been successfully translated from basic studies into clinical practice., (Copyright © 2020 Kato, Takeuchi, Akashi and Eto.)

Innate immune memory is characterized by a modulation in the magnitude with which innate immune cells such as monocytes and macrophages respond to potential dangers, subsequent to previous exposure to the same or unrelated agents. In this study, we have examined the capacity of gold nanoparticles (AuNP), which are already in use for therapeutic and diagnostic purposes, to modulate the innate memory induced by bacterial agents. The induction of innate memory was achieved in vitro by exposing human primary monocytes to bacterial agents (lipopolysaccharide -LPS-, or live Bacille Calmette-Guérin -BCG) in the absence or presence of AuNP. After the primary activation, cells were allowed to return to a resting condition, and eventually re-challenged with LPS. The induction of memory was assessed by comparing the response to the LPS challenge of unprimed cells with that of cells primed with bacterial agents and AuNP. The response to LPS was measured as the production of inflammatory (TNFα, IL-6) and anti-inflammatory cytokines (IL-10, IL-1Ra). While ineffective in directly inducing innate memory per se, and unable to influence LPS-induced tolerance memory, AuNP significantly affected the memory response of BCG-primed cells, by inhibiting the secondary response in terms of both inflammatory and anti-inflammatory factor production. The reprogramming of BCG-induced memory towards a tolerance type of reactivity may open promising perspectives for the use of AuNP in immunomodulatory approaches to autoimmune and chronic inflammatory diseases., Competing Interests: The authors declare no conflict of interest.

Two Pt(IV) prodrugs, Cx-platin-Cl and Cx-DN604-Cl, derived from the conjugation of cisplatin or DN604 with a CK2 inhibitor CX-4945, were constructed to suppress DNA damage repair-related elements. During in vitro biological studies, the Pt(IV) prodrugs had excellent cytotoxicity superior to cisplatin and DN604 to reverse drug resistance. Further mechanistic investigations revealed that the powerful anticancer activity of Cx-platin-Cl and Cx-DN604-Cl arisen from its suppression of JWA-XRCC1-mediated single-strand breaks repair. The emerging Pt(IV) prodrugs inhibited the growth of the xenografted tumors of C57BL6 and nude mice apart from JWA -/- mice. Between them, Cx-platin-Cl augmented the infiltration and proliferation of T eff cells, alleviated the recruitment of T reg cells. The results provided compelling preclinical support that Cx-platin-Cl and Cx-DN604-Cl could reverse chemo-immune resistance via decaying JWA-XRCC1-mediated SSBR and immunosuppression, improving the development of emerging Pt(IV) candidate as a potential immunotherapeutic agent for cancer resistant prevention., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Development of neutralizing antibodies against biotherapeutic agents administered to prevent or treat various clinical conditions is a longstanding and growing problem faced by patients, medical providers and pharmaceutical companies. The hemophilia A community has deep experience with attempting to manage such deleterious immune responses, as the lifesaving protein drug factor VIII (FVIII) has been in use for decades. Hemophilia A is a bleeding disorder caused by genetic mutations that result in absent or dysfunctional FVIII. Prophylactic treatment consists of regular intravenous FVIII infusions. Unfortunately, 1/4 to 1/3 of patients develop neutralizing anti-FVIII antibodies, referred to clinically as "inhibitors," which result in a serious bleeding diathesis. Until recently, the only therapeutic option for these patients was "Immune Tolerance Induction," consisting of intensive FVIII administration, which is extraordinarily expensive and fails in ~30% of cases. There has been tremendous recent progress in developing novel potential clinical alternatives for the treatment of hemophilia A, ranging from encouraging results of gene therapy trials, to use of other hemostatic agents (either promoting coagulation or slowing down anti-coagulant or fibrinolytic pathways) to "bypass" the need for FVIII or supplement FVIII replacement therapy. Although these approaches are promising, there is widespread agreement that preventing or reversing inhibitors remains a high priority. Risk profiles of novel therapies are still unknown or incomplete, and FVIII will likely continue to be considered the optimal hemostatic agent to support surgery and manage trauma, or to combine with other therapies. We describe here recent exciting studies, most still pre-clinical, that address FVIII immunogenicity and suggest novel interventions to prevent or reverse inhibitor development. Studies of FVIII uptake, processing and presentation on antigen-presenting cells, epitope mapping, and the roles of complement, heme, von Willebrand factor, glycans, and the microbiome in FVIII immunogenicity are elucidating mechanisms of primary and secondary immune responses and suggesting additional novel targets. Promising tolerogenic therapies include development of FVIII-Fc fusion proteins, nanoparticle-based therapies, oral tolerance, and engineering of regulatory or cytotoxic T cells to render them FVIII-specific. Importantly, these studies are highly applicable to other scenarios where establishing immune tolerance to a defined antigen is a clinical priority., (Copyright © 2020 Lacroix-Desmazes, Voorberg, Lillicrap, Scott and Pratt.)

The present study was carried out to investigate the toxic effects of diazinon on growth performance, hepato-renal function, antioxidant system, innate immune response and comparing the protective role of dietary Chlorella vulgaris (CV) algae and β-glucan in intoxicated Nile tilapia (Oreochromis niloticus). One hundred and eighty healthy Nile tilapia (20 ± 6.1 g) were distributed equally into four groups; control group, DZN group (0.28 mg/L), DZN-CV group (5% CV) and DZN-β-glucan group (0.1% β-glucan) and treatments conducted for about 60 days. The results revealed that administration of DZN significantly increased serum liver enzymes, uric acid, creatinine, and malondialdehyde (MDA) in different tissues. Meanwhile, glutathione (GSH) and superoxide dismutase (SOD) in different tissues, as well as IgM, C-reactive protein (CRP), respiratory burst, lysozyme and bactericidal activities were significantly decreased in DZN group. In addition, expression of TNF-α gene was up-regulated and IL-10 was down-regulated in spleen of DZN intoxicated fish. The treatment of DZN exposed fish with CV and β-glucan supplemented diets ameliorated hepatic damage and enhanced antioxidant activity and innate immune responses. Furthermore, dietary Chlorella vulgaris and β-glucan have a potent anti-inflammatory effect as they remarkably increased the expression of IL-10 and decreased TNF-α gene expression. The results also revealed that fish in DZN-CV group had the highest survival rate, final body weight (FBW) and body weight gain (BWG). On the other hand, feed conversion ratio (FCR), specific growth rate (SGR), and protein efficiency ratio (PER) of control, DZN-CV, and DZN- β-glucan were higher than DZN group. However, the hepatosomatic index (HSI) and spleen-somatic index (SSI) were higher in DZN group than other experimental groups. Overall, CV and β-glucan can be recommended as a feed supplement to improve immunosuppression, oxidative damage, growth performance and hemato-biochemical alterations induced by DZN toxicity in Nile tilapia., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Tumor-promoting inflammation and the avoidance of immune destruction are hallmarks of cancer. While innate immune cells, such as neutrophils, monocytes, and macrophages, are critical mediators for sterile and nonsterile inflammation, persistent inflammation, such as that which occurs in cancer, is known to disturb normal myelopoiesis. This disturbance leads to the generation of immunosuppressive myeloid cells, such as myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). Due to their potent suppressive activities against effector lymphocytes and their abundance in the tumor microenvironment, immunosuppressive myeloid cells act as a major barrier to cancer immunotherapy. Indeed, various therapeutic approaches directed toward immunosuppressive myeloid cells are actively being tested in preclinical and clinical studies. These include anti-inflammatory agents, therapeutic blockade of the mobilization and survival of myeloid cells, and immunostimulatory adjuvants. More recently, immune checkpoint molecules expressed on tumor-infiltrating myeloid cells have emerged as potential therapeutic targets to redirect these cells to eliminate tumor cells. In this review, we discuss the complex crosstalk between cancer-related inflammation and immunosuppressive myeloid cells and possible therapeutic strategies to harness antitumor immune responses.

Excessive immune-mediated inflammatory reaction plays a deleterious role in ventricular remodelling after myocardial infarction (MI). Interleukin (IL)-38 is a newly characterized cytokine of the IL-1 family and has been reported to exert a protective effect in some autoimmune diseases. However, its role in cardiac remodelling post-MI remains unknown. In this study, we found that the expression of IL-38 was increased in infarcted heart after MI induced in C57BL/6 mice by permanent ligation of the left anterior descending artery. In addition, our data showed that ventricular remodelling after MI was significantly ameliorated after recombinant IL-38 injection in mice. This amelioration was demonstrated by better cardiac function, restricted inflammatory response, attenuated myocardial injury and decreased myocardial fibrosis. Our results in vitro revealed that IL-38 affects the phenotype of dendritic cells (DCs) and IL-38 plus troponin I (TNI)-treated tolerogenic DCs dampened adaptive immune response when co-cultured with CD4 + T cells. In conclusion, IL-38 plays a protective effect in ventricular remodelling post-MI, one possibility by influencing DCs to attenuate inflammatory response. Therefore, targeting IL-38 may hold a new therapeutic potential in treating MI., (© 2019 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Anti-CD154 blockade-based regimens remain unequaled in prolonging graft survival in various organ transplantation models. Several studies have focused on transplantation tolerance with the anti-CD154 blockade, but none of these studies has investigated the mechanisms associated with its use as the sole treatment in animal models, delaying our understanding of anti-CD154 blockade-mediated immune tolerance. The purpose of this study was to investigate the mechanism underlying the anti-CD154 monoclonal antibody (mAb) blockade in inducing immune tolerance using an intrahepatic murine allogeneic islet transplantation model. Allogeneic BALB/c AnHsd (BALB/c) islets were infused into the liver of diabetic C57BL/6 (B6) mice via the cecal vein. Anti-CD154 mAb (MR1) was administered on -1, 0, 1, 3, 5, and 7 d posttransplantation at 0.5 mg per mouse. We showed that short-term MR1 monotherapy could prolong the allogeneic islet grafts to more than 250 d in the murine intrahepatic islet transplantation model. The second islet grafts transplanted under the kidney capsule of the recipients were protected from rejection. We also found that rejection of same-donor skin grafts transplanted to the tolerant mice was modestly delayed. Using a DEREG mouse model, FoxP3+ regulatory T (Treg) cells were shown to play important roles in transplantation tolerance. In mixed lymphocyte reactions, Treg cells from the tolerant mice showed more potency in suppressing BALB/c splenocyte-stimulated Teff cell proliferation than those from naïve mice. In this study, we demonstrated for the first time that a short-term anti-CD154 mAb single treatment could induce FoxP3+ Treg cell-mediated immune tolerance in the intrahepatic murine allogeneic islet transplantation model.

Trace elements such as copper (Cu) and arsenic (As) are two of the major contaminants and well-known inducers of cognitive deficits and neurobehavioral changes. This study evaluated the immunotoxicity of their individual or combined exposure on different brain regions in chickens. Consequently, nuclear damage and organelle lesions, especially mitochondria were observed under Cu or/and As stress, in which positive regulation of key proteins, dynamin-related protein 1 (Drp1), Cytochrome C (Cyt c), BCL2-associated X (Bax), Caspases 3 and P53 was detected by qRCR and Western blot analyses, indicating disturbed mitochondrial dynamic equilibrium and apoptosis execution. In addition, qRCR analysis confirmed the involvement of cytokines secreted by different populations of helper T cells, indicative of cellular immunity. Gene expression studies showed marked up regulation of Th1/Th17 cytokines along with heat shock protein (HSP) 70, a synergism was noted in co-administration group. Interesting, lower apoptosis index was noted in brainstem compared to cerebrum and cerebellum. An intense immunosuppression and heat shock response against Cu or/and As was also seen in cerebrum and cerebellum but not in brainstem. In conclusion, our study suggests a synergistic neurotoxicity in chickens under Cu and As exposure. These findings provide a basic understanding of mitochondrial abnormality-initiated neuropathology in response to environmental pollutant mixtures, suggesting an adaptive response to the frangibility of the central nerve system., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Human heat-shock protein 60 (HSP60) is an autoantigen involved in the pathogenesis of rheumatoid arthritis (RA). Epitopes derived from HSP60 can trigger activation of regulatory T cells (Treg). CIGB-814 is an altered peptide ligand (APL) derived from HSP60. In preclinical models, this peptide had anti-inflammatory effects and increased Treg. The results from phase I clinical trial indicated that CIGB-814 was safe and activated mechanisms associated with induction of tolerance. Biodistribution profile for inducers of tolerance is crucial for triggering its effects. The primary goal of this study in Lewis rats was to identify (1) the target organs of CIGB-814 and (2) the pharmacokinetics (PK) profile. 125 I-CIGB-814 administered subcutaneously at three dose levels was distributed in the thyroid gland, but also at considerable levels to the stomach and small and large intestines. In addition, concentration of CIGB-814 was increased in lymph nodes (LNs) at 24 h, compared with 4-h post-administration. Small intestine and LNs are excellent sites for induction of tolerance, due to the characteristics of dendritic cells in these tissues. Maximum concentration of CIGB-814 in blood of Lewis rats at 0.5 to 1 h agrees with PK profile determined for patients. Altogether, these results support therapeutic possibilities of CIGB-814 for RA.

Nowadays, the development of factor VIII and IX inhibitors in patients with hemophilia is considered as the most challenging in the treatment of hemophilia. Immune tolerance induction (ITI) therapy is an approach for eradication of inhibitors. Some ITI protocols are routinely in use for the eradication of inhibitors in patients with hemophilia. Moreover, such a therapeutic regimen may facilitate the tendency to reduced bone density in patients with inhibitor. This study scheduled to investigate whether that predisposing role of ITI protocols with an immunosuppressive agent has considered or not. By a literature review, published ITI protocols in hemophilia with inhibitors were evaluated. Among them, 51 papers found and studied thoroughly. None of them had performed the bone mineral examination in patients with hemophilia and inhibitor under treatment. Since there are 2 coexisting facilitating factors in these protocols, considering the bone mineral density study for patients with inhibitor who are undergoing ITI protocols with an immunosuppressive agent is recommended.

Aim: We aim to demonstrate that a local nanoparticle-mediated hyperthermia can effectively eliminate tumor-associated Tregs and thereby boost checkpoint blockade-based immunotherapy. Materials & methods: Photothermal therapy (PTT), mediated with systemically administered stealthy iron-oxide nanoparticles, was applied to treat BALB/c mice bearing 4T1 murine breast tumors. Flow cytometry was applied to evaluate both Treg and CD8 + T-cell population. Tumor growth following combination therapy of both PTT and anti-CTLA-4 was further evaluated. Results: Our data reveal that tumor-associated Tregs can be preferentially depleted via iron-oxide nanoparticles-mediated PTT. When combining PTT with anti-CTLA-4 immunotherapy, we demonstrate a significant inhibition of syngeneic 4T1 tumor growth. Conclusion: This study offers a novel strategy to overcome Treg-mediated immunosuppression and thereby to boost cancer immunotherapy.

Di-(2-ethylhexyl) phthalate (DEHP), a common pollutant in the water environment, has been reported to be associated with immune functions, especially aquatic organisms. However, whether DEHP exposure causes neutrophils toxicity in common carp is still unclear. To investigate the toxic effect of DEHP on immune functions, common carp neutrophils were exposed to DEHP (40 μmol/L and 200 μmol/L) for 2 h. The common carp neutrophils exposed to DEHP showed a decrease in neutrophil phagocytosis rate compared with control group. DEHP exposure induced a significant decrease in mRNA expression levels of inflammatory cytokines-related genes (Interleukin-6, Interleukin-8, transforming growth factor, tumor necrosis factor (TNF)-α, TNF-R1, TNF-T1, Interferon (IFN)-2a, IFN-g2b, IFN-g1) in common carp neutrophils, while the expression levels of IL-1β and IL-10 were increased compared with control group (P < 0.05). Furthermore, the detection of cytochrome P450 enzyme related genes showed that the mRNA expression levels of CYP (cytochrome P450 proteins)-1A, CYP-1B1, CYP-C1, CYP-2K were significantly decreased, and the mRNA expression level of CYP-3A was significantly reduced (P < 0.05). The results indicated that DEHP could affect the phagocytic ability of neutrophils by regulating the expression of inflammatory cytokines and disrupting cytochrome P450 homeostasis, which caused the immunosuppression in common carp., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of various doses of the anti-CD40 monoclonal antibody bleselumab (ASKP1240) in de novo kidney transplant recipients receiving concomitant standard immunosuppression over 90 days posttransplant. Transplant recipients were randomized (1:1:1:1:1) to bleselumab 50 mg, 100 mg, 200 mg, or 500 mg, or placebo, in addition to standard maintenance immunosuppression. The primary pharmacokinetic endpoints were AUC inf , C max , and AUC last . The primary pharmacodynamic endpoint was B cell CD40 receptor occupancy over time. Overall, 50 kidney transplant recipients were randomized; 45 received their randomized treatment (bleselumab [n = 37] or placebo [n = 8]). AUC inf and AUC last demonstrated a more than dose-proportional increase in the range of 50-500 mg, and C max increased linearly with increasing dose. Maximal receptor occupancy for B cell CD40 was reached at all dose levels and was prolonged as dose increased. No kidney transplant recipients experienced cytokine release syndrome or a thromboembolic event. Treatment-emergent anti-bleselumab antibodies were found in one kidney transplant recipient in the bleselumab 50 mg group; these were detected only at Day 7. Overall, bleselumab demonstrated nonlinear pharmacokinetics and dose-dependent prolonged B cell CD40 receptor occupancy and was well tolerated at all doses (ClinicalTrials.gov: NCT01279538)., (© 2019 The Authors. American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of The American Society of Transplantation and the American Society of Transplant Surgeons.)

Siplizumab, a humanized anti-CD2 monoclonal antibody, has been used in conditioning regimens for hematopoietic cell transplantation and tolerance induction with combined kidney-bone marrow transplantation. Siplizumab-based tolerance induction regimens deplete T cells globally while enriching regulatory T cells (Tregs) early posttransplantation. Siplizumab inhibits allogeneic mixed-lymphocyte reactions (MLRs) in vitro. We compared the impact of siplizumab on Tregs versus other T cell subsets in HLA-mismatched allogeneic MLRs using PBMCs. Siplizumab predominantly reduced the percentage of CD4 + and CD8 + effector memory T cells, which express higher CD2 levels than naïve T cells or resting Tregs. Conversely, siplizumab enriched proliferating CD45RA - FoxP3 HI cells in MLRs. FoxP3 expression was stable over time in siplizumab-containing cultures, consistent with enrichment for bona fide Tregs. Consistently, high-throughput TCRβ CDR3 sequencing of sorted unstimulated and proliferating T cells in MLRs revealed selective expansion of donor-reactive Tregs along with depletion of donor-reactive CD4 + effector/memory T cells in siplizumab-containing MLRs. These results indicate that siplizumab may have immunomodulatory functions that may contribute to its success in tolerance-inducing regimens. Our studies also confirm that naïve in addition to effector/memory T cells contribute to the allogeneic MLR and mandate further investigation of the impact of siplizumab on alloreactive naïve T cells., (© 2019 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Gastric cancer is one of the most common and deadly neoplasms with limited effective treatments. The emergence of the immunotherapy has brought great expectations for cancer patients. Sophoridine is extracted from the seeds of sophora alopecuroides and has various pharmacological actions including anti-tumor, anti-inflammatory, anti- arrhythmia and anti-virus. However, the effect of Sophoridine on gastric cancer microenvironment immunity and its underling mechanism remains poorly known. This study was aimed to investigate the effect of Sophoridine on the polarization status of gastric tumor-associated macrophages (TAMs) and its underlying mechanism. We isolated primary bone marrow-derived macrophages (BMDMs) and primary CD8 + T cells to perform coculture assay. Sophoridine educated TAMs polarize to M1-TAMs and suppressed M2-TAMs polarization through TLR4/IRF3 axis. Sophoridine-treated TAMs exhibited stronger pro-inflammatory function through upregulation the expression of INOS, IFN-β and IL-12α, and downregulation the expression of Arg-1, CD206 and IL-10. Sophoridine -primed TAMs increased the proliferation and cytotoxic function of CD8 + T by upregulating the expression of Granzyme-B, TNF-α and Perforin, and downregulated the expression of CD8 + T cells function exhaustion markers PD-1, Tim-3 and Lag-3. Furthermore, Sophoridine inhibited the migration ability of macrophage by decrease the CCR2 expression. Thus, Sophoridine acted on macrophages and CD8 + T cells to reshape gastric cancer immune microenvironment. Our studies provided preclinical basis for clinical application of Sophoridine., (Copyright © 2019 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Chimeric antigen receptor T (CAR-T) cells are T cells engineered to express specific synthetic antigen receptors that can recognize antigens expressed by tumor cells, which after the binding of these antigens to the receptors are eliminated, and have been adopted to treat several kinds of malignancies. Autoimmune diseases (AIDs), a class of chronic disease conditions, can be broadly separated into autoantibody-mediated and T cell-mediated diseases. Treatments for AIDs are focused on restoring immune tolerance. However, current treatments have little effect on immune tolerance inverse; even the molecular target biologics like anti-TNF α inhibitors can only mildly restore immune balance. By using the idea of CAR-T cell treatment in tumors, CAR-T cell-derived immunotherapies, chimeric autoantibody receptor T (CAAR-T) cells, and CAR regulatory T (CAR-T) cells bring new hope of treatment choice for AIDs., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2019 Yuehong Chen et al.)

In neonatal T cells, a low response to infection contributes to a high incidence of morbidity and mortality of neonates. Here we have evaluated the impact of the cytoplasmic and mitochondrial levels of Reactive Oxygen Species of adult and neonatal CD8+ T cells on their activation potential. We have also constructed a logical model connecting metabolism and ROS with T cell signaling. Our model indicates the interplay between antigen recognition, ROS and metabolic status in T cell responses. This model displays alternative stable states corresponding to different cell fates, i.e. quiescent, activated and anergic states, depending on ROS levels. Stochastic simulations with this model further indicate that differences in ROS status at the cell population level contribute to the lower activation rate of neonatal, compared to adult, CD8+ T cells upon TCR engagement. These results are relevant for neonatal health care. Our model can serve to analyze the impact of metabolic shift during cancer in which, similar to neonatal cells, a high glycolytic rate and low concentrations of glutamine and arginine promote tumor tolerance., Competing Interests: The authors have declared that no competing interests exist.

Background: Mesenchymal stem cells (MSCs) have been shown to alleviate acute lung injury (ALI) via paracrine hepatocyte growth factor (HGF) and to induce the differentiation of dendritic cells (DCs) into tolerogenic dendritic cells (DCregs) and participate in the immune response. However, whether MSCs induce the production of DCregs by secreting HGF to alleviate early ALI remains unclear. We observed that the protective effect of mouse bone marrow-derived MSCs against lipopolysaccharide (LPS)-induced ALI was achieved by inducing mature DCs (mDCs) to differentiate into DCregs, and its mechanism is related to the activation of the HGF/Akt pathway., Methods: MSCs or MSCs with overexpression or knockdown of HGF were cocultured with DCs derived from mouse bone marrow using a Transwell system for 3 days. Moreover, we used MSCs or MSCs with overexpression or knockdown of HGF to treat LPS-induced ALI mice for 24 h. Flow cytometry was performed to measure the phagocytosis, accumulation, and maturation of DCs, as well as proliferation of T cells. Lung injury was estimated by lung wet weight to body weight ratio (LWW/BW) and histopathological analysis. Furthermore, we used the Akt inhibitor MK-2206 in a coculture system to elucidate the role of the HGF/Akt pathway in regulating the differentiation of DCs into regulatory DCs and relieving lung injury in early ALI mice., Results: Immature DCs (imDCs) were induced to mature after 24 h of LPS (50 ng/ml) stimulation. MSCs or HGF induced the differentiation of mDCs into regulatory DCs characterized by low expression of MHCII, CD86, and CD40 molecules, strong phagocytic function, and the ability to inhibit T cell proliferation. The effect of MSCs on DCregs was enhanced with the increase in HGF secretion and was weakened with the decrease in HGF secretion. DCregs induced by recombinant HGF were attenuated by the Akt inhibitor MK-2206. Lung DC aggregation and mDC ratio increased in LPS-induced ALI mice, while treatment with MSCs decreased lung DC aggregation and maturation and alleviated lung pathological injury. High expression of the HGF gene enhanced the above effect of MSCs, while decreased expression of HGF weakened the above effect of MSCs., Conclusions: MSCs alleviate early ALI via paracrine HGF by inducing mDCs to differentiate into regulatory DCs. Furthermore, the mechanism of HGF-induced differentiation of mDCs into DCregs is related to the activation of the Akt pathway.

Glioblastoma (GBM) is a non-T-cell-inflamed cancer characterized by an immunosuppressive microenvironment that impedes dendritic cell maturation and T-cell cytotoxicity. Proangiogenic cytokines such as VEGF and angiopoietin-2 (Ang-2) have high expression in glioblastoma in a cell-specific manner and not only drive tumor angiogenesis and vascular permeability but also negatively regulate T-lymphocyte and innate immune cell responses. Consequently, the alleviation of immunosuppression might be a prerequisite for successful immune checkpoint therapy in GBM. We here combined antiangiogenic and immune checkpoint therapy and demonstrated improved therapeutic efficacy in syngeneic, orthotopic GBM models. We observed that blockade of VEGF, Ang-2, and programmed cell death protein-1 (PD-1) significantly extended survival compared with vascular targeting alone. In the GBM microenvironment, triple therapy increased the numbers of CTLs, which inversely correlated with myeloid-derived suppressor cells and regulatory T cells. Transcriptome analysis of GBM microvessels indicated a global vascular normalization that was highest after triple therapy. Our results propose a rationale to overcome tumor immunosuppression and the current limitations of VEGF monotherapy by integrating the synergistic effects of VEGF/Ang-2 and PD-1 blockade to reinforce antitumor immunity through a normalized vasculature., (©2019 American Association for Cancer Research.)

Background: Oral enrofloxacin treatment altered the gut microbiome promoting anti-inflammatory bacteria. The dysbiosis promotes regulatory cell induction in the intestines and in the periphery, which suppresses contact sensitivity. Bacterial-derived signals promote regulatory cell induction both directly and indirectly by influencing the phenotype of dendritic cells (DC)., Methods: Oral treatment with broad-spectrum antibiotic enrofloxacin was used to evaluate how gut flora perturbation shapes the immune response in the gut and the periphery., Results: Enrofloxacin-induced dysbiosis creates an anti-inflammatory environment characterized by increased IL-10 concentration in the gut lumen and tissues. The production of IFN-γ and IL-17A did not change. Oral enrofloxacin treatment skewed the profile of the immune response towards an anti-inflammatory phenotype locally in small intestinal Peyer's Patches (PP) and systematically in the spleen (SPL). Enrofloxacin administration changed immune response in PP by increasing TGF-β secretion from an increased percentage of TGF-β-producing. In the SPL, enrofloxacin treatment increased the secretion of TGF-β and IL-10 and decreased the secretion of IL-17A and IFN-γ. The shift in cytokine profile correlated with a higher percentage of latency-associated peptide and IL-10-producing cells and a decreased percentage of IFN-γ-producing T cells. This anti-inflammatory immune response in the PP and SPL promoted a higher frequency of tolerogenic DC., Conclusion: Our data indicate that two-week enrofloxacin treatment induces dysbiosis, skews immune response towards an anti-inflammatory phenotype, and elevates secretion of TGF-β and IL-10 in the intestines and periphery. Additionally, we observed higher frequencies of tolerogenic DC, characterized by CD11b and IL-10 expression, which are known inducers of Treg cells., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Combining autoantigens with immune-modulating drugs has emerged as an attractive approach to selectively reinstate tolerance in autoimmune diseases. The disparate properties of autoantigens and small-molecule immunosuppressants commonly used to treat autoimmune diseases can confound efforts to co-deliver these therapies. However, both components may be co-delivered with adjuvants which have been successful in delivering antigens to immune cells. We evaluated several common adjuvants as vehicles to co-deliver a model antigen and immunosuppressant, ovalbumin (OVA) and dexamethasone (DEX), respectively. Formulations were developed, and the release of DEX from adjuvants was investigated. Next, the effect of adjuvant, DEX, and OVA was tested in vitro using a DC line. A MF59-analog (MF59a) formulation was advanced to more sophisticated co-culture studies using OVA-primed bone marrow-derived dendritic cells and splenocytes or T-cells from OT-II mice. Most of these studies indicated MF59a-based antigen-specific immunotherapies could diminish the markers of inflammation associated with OVA recognition. We rationalized MF59a co-delivery of antigen and drug could reduce the risk of side effects typically associated with these drugs and reinstate immune tolerance, thus prompting continued investigation of emulsion adjuvants as delivery vehicles for antigen-specific immunotherapy of autoimmune diseases., (Copyright © 2019 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Background: Recessive dystrophic epidermolysis bullosa (RDEB) is a severe systemic genodermatosis lacking therapies beyond supportive care for its extensive, life-limiting manifestations., Objectives: To report the safety and preliminary responses of 10 patients with RDEB to bone marrow transplant (BMT) with post-transplant cyclophosphamide (PTCy BMT) after reduced-intensity conditioning with infusions of immunomodulatory donor-derived mesenchymal stromal cells (median follow-up 16 months)., Methods: BMT toxicities, donor blood and skin engraftment, skin biopsies, photographic and dynamic assessments of RDEB disease activity were obtained at intervals from pre-BMT to 1 year post-BMT., Results: Related donors varied from haploidentical (n = 6) to human leucocyte antigen (HLA)-matched (n = 3), with one HLA-matched unrelated donor. Transplant complications included graft failure (n = 3; two pursued a second PTCy BMT), veno-occlusive disease (n = 2), posterior reversible encephalopathy (n = 1) and chronic graft-versus-host disease (n = 1; this patient died). In the nine ultimately engrafted patients, median donor chimerism at 180 days after transplant was 100% in peripheral blood and 27% in skin. Skin biopsies showed stable (n = 7) to improved (n = 2) type VII collagen protein expression by immunofluorescence and gain of anchoring fibril components (n = 3) by transmission electron microscopy. Early signs of clinical response include trends toward reduced body surface area of blisters/erosions from a median of 49·5% to 27·5% at 100 days after BMT (P = 0·05), with parental measures indicating stable quality of life., Conclusions: PTCy BMT in RDEB provides a means of attaining immunotolerance for future donor-derived cellular grafts (ClinicalTrials.gov identifier NCT02582775). What's already known about this topic? Severe, generalized recessive dystrophic epidermolysis bullosa (RDEB) is marked by great morbidity and early death. No cure currently exists for RDEB. Bone marrow transplant (BMT) is the only described systemic therapy for RDEB. What does this study add? The first description of post-transplant cyclophosphamide (PTCy) BMT for RDEB. PTCy was well tolerated and provided excellent graft-versus-host disease prophylaxis, replacing long courses of calcineurin inhibitors in patients receiving human leucocyte antigen-matched sibling BMT. What is the translational message? The PTCy BMT platform permits identification of a suitable related donor for most patients and for subsequent adoptive transfer of donor nonhaematopoietic cells after establishment of immunological tolerance., (© 2019 British Association of Dermatologists.)

Introduction: There is increasing awareness that different anesthetic and analgesic techniques may impact outcomes after oncological surgery, generally through modifying effects on the immune system but potentially via other mechanisms including mitigating the surgical stress response. This narrative review aims to summarize the mechanisms underlying the effect of perioperative factors on oncological outcomes, with an emphasis on the available urologic literature., Methods: Literature on anesthetic technique (i.e., general vs. regional) and oncological outcomes were reviewed with a particular focus on urological studies., Results: In prostate cancer surgery, the risk of mortality has been reported to be reduced with the use of regional (i.e., neuraxial) anesthesia, but there was no association between anesthetic technique and progression-free or biochemical recurrence-free survival. In nonmuscle invasive bladder cancer, regional anesthesia has been associated with lower recurrence rates and longer time to recurrence following transurethral resection of bladder tumor., Conclusions: This review highlights the role of regional anesthesia to improve oncoimmunological responses after surgery, potentially through decreased use of volatile anesthetics and opioids, decreased activation of the surgical stress response, and a direct local anesthetic-mediated anti-inflammatory effect. Available urological literature suggests an association of anesthetic type and outcomes for nonmuscle invasive bladder cancer and prostate cancer surgeries but the evidence is limited. Prospective studies are needed to further investigate the relationship between anesthetic technique and urologic oncological outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

As the first FDA-approved proteasome inhibitor drug, bortezomib has been used for the treatment of multiple myeloma and lymphoma. However, its effects alone or in combination with other immunosuppressants on allogeneic islet transplantation have not been reported so far. In this study, we showed that the short-term combination treatment of low-dose bortezomib and rapamycin significantly prolonged the survival of islet allografts. Short-term treatment of low-dose (0.05 mg/kg or 0.1 mg/kg) bortezomib reduced the MHC class II expression in dendritic cells (DCs) of alloantigen-sensitized mice, and prolonged the islet allograft survival for up to 50 days in diabetic mice. Notably, when bortezomib was combined with rapamycin, it induced islet-specific immunological tolerance which allowed the acceptance of a second graft without additional immunosuppression. This regimen dramatically reduced the alloantigen-specific IFN-γ-producing T cells in the spleen, and increased regulatory T cells both at the graft site and in the spleen. Therefore, we propose that short-term treatment of low-dose bortezomib and rapamycin could be a new tolerance-promoting immunosuppressive regimen for allogeneic islet transplantation., (Copyright © 2019. Published by Elsevier B.V.)

Background: Platycodon grandiflorum is a flowering plant that is used in traditional medicine for treating pulmonary and respiratory disorders. It exerts various pharmacological effects, including immunomodulatory and anti-cancer activities. The purpose of this study was to confirm the in vitro and in vivo immune-enhancing effects of P. grandiflorum extract (PGE) on splenocytes isolated from cyclophosphamide (CP)-induced immunosuppressed rats., Methods: For in vitro analysis, splenocytes were treated with PGE at various doses along with CP. Cell viability was measured by a WST-1 assay, and NK cell activity and cytotoxic T lymphocyte (CTL) activity was also examined. In addition, immunoglobulin A (IgA), IgG, and cytokine levels were measured. For in vivo analysis, Sprague Dawley rats were treated with various doses of PGE along with CP. Complete blood count (CBC) was performed, and plasma levels of IgA, IgG, TNF-α, IFN-γ, IL-2, and IL-12 were quantified. Additionally, tissue damage was assessed through histological analyses of the thymus and spleen., Results: PGE treatment enhanced cell viability and natural killer cell and cytotoxic T lymphocyte activity, and increased the production of CP-induced inflammatory cytokines (TNF-α, IFN-γ, IL-2, and IL-12) and immunoglobulins (IgG and IgA) in splenocytes. In addition, in CP-treated rats, PGE treatment induced the recovery of white blood cell, neutrophil, and lymphocyte counts, along with mid-range absolute counts, and increased the serum levels of inflammatory cytokines (TNF-α, IFN-γ, IL-2, and IL-12) and immunoglobulins (IgG and IgA). Moreover, PGE attenuated CP-induced spleen and thymic damage., Conclusions: Our results confirmed that PGE exerts an immune-enhancing effect both in vitro and in vivo, suggesting that PGE may have applications as a component of immunostimulatory agents or as an ingredient in functional foods.

Oral tolerance is defined as the specific suppression of cellular and/or humoral immune responses to an Ag by prior administration of the Ag through the oral route. Although the investigation of oral tolerance has classically involved Ag feeding, we have found that oral administration of anti-CD3 mAb induced tolerance through regulatory T (Treg) cell generation. However, the mechanisms underlying this effect remain unknown. In this study, we show that conventional but not plasmacytoid dendritic cells (DCs) are required for anti-CD3-induced oral tolerance. Moreover, oral anti-CD3 promotes XCL1 secretion by small intestine lamina propria γδ T cells that, in turn, induces tolerogenic XCR1 + DC migration to the mesenteric lymph node, where Treg cells are induced and oral tolerance is established. Consistent with this, TCRδ -/- mice did not develop oral tolerance upon oral administration of anti-CD3. However, XCL1 was not required for oral tolerance induced by fed Ags, indicating that a different mechanism underlies this effect. Accordingly, oral administration of anti-CD3 enhanced oral tolerance induced by fed MOG 35-55 peptide, resulting in less severe experimental autoimmune encephalomyelitis, which was associated with decreased inflammatory immune cell infiltration in the CNS and increased Treg cells in the spleen. Thus, Treg cell induction by oral anti-CD3 is a consequence of the cross-talk between γδ T cells and tolerogenic DCs in the gut. Furthermore, anti-CD3 may serve as an adjuvant to enhance oral tolerance to fed Ags., (Copyright © 2019 by The American Association of Immunologists, Inc.)