Estimating the key outcomes and hepatocellular carcinoma risk in patients in immune-tolerant phase of chronic hepatitis B virus infection: A systematic review and meta-analysis.

The question of whether patients in the immune-tolerant (IT) phase of chronic hepatitis B virus (HBV) infection should undergo antiviral therapy and determine the optimal regimen remains unclear. A comprehensive search of PubMed, Embase, MEDLINE, Cochrane Library, and Wanfang Data from inception to 5 December 2023, was conducted. Studies reporting on key outcomes such as HBV DNA undetectability, HBeAg loss or seroconversion, HBsAg loss or seroconversion, and hepatocellular carcinoma (HCC) incidence in patients in the IT phase of chronic HBV infection were included. In total, 23 studies were incorporated. Approximately 4% of patients in the IT phase achieved spontaneous HBeAg loss over 48 weeks of follow-up. Antiviral therapy demonstrated a favourable impact on HBV DNA negative conversion (Children: risk ratios [RR] = 6.83, 95% CI: 2.90-16.05; Adults: RR = 25.84, 95% CI: 6.47-103.31) and HBsAg loss rates (Children: RR = 9.49, 95% CI: 1.74-51.76; Adults: RR = 7.35, 95% CI: 1.41-38.27) for patients in the IT phase. Subgroup analysis revealed that in adult patients in the IT phase, interferon plus nucleos(t)ide analogues (NA)-treated patients exhibited a higher pooled rate of HBsAg loss or seroconversion than those treated with NA monotherapy (9% vs. 0%). Additionally, the pooled annual HCC incidence for patients in the IT phase was 3.03 cases per 1000 person-years (95% CI: 0.99-5.88). Adult patients in the IT phase had a significantly lower HCC incidence risk than HBeAg-positive indeterminate phase patients (RR = 0.46, 95% CI: 0.32-0.66), with no significant differences observed between IT and immune-active phases. Presently, there is insufficient evidence solely based on reducing the risk of HCC incidence, to recommend treating patients in the IT phase of chronic HBV infection. However, both adult and paediatric patients in the IT phase responded well to antiviral therapy, showing favourable rates of HBsAg loss or seroconversion.

Progestogen-driven B7-H4 contributes to onco-fetal immune tolerance.

Immune tolerance mechanisms are shared in cancer and pregnancy. Through cross-analyzing single-cell RNA-sequencing data from multiple human cancer types and the maternal-fetal interface, we found B7-H4 (VTCN1) is an onco-fetal immune tolerance checkpoint. We showed that genetic deficiency of B7-H4 resulted in immune activation and fetal resorption in allogeneic pregnancy models. Analogously, B7-H4 contributed to MPA/DMBA-induced breast cancer progression, accompanied by CD8+ T cell exhaustion. Female hormone screening revealed that progesterone stimulated B7-H4 expression in placental and breast cancer cells. Mechanistically, progesterone receptor (PR) bound to a newly identified -58 kb enhancer, thereby mediating B7-H4 transcription via the PR-P300-BRD4 axis. PR antagonist or BRD4 degrader potentiated immunotherapy in a murine B7-H4+ breast cancer model. Thus, our work unravels a mechanistic and biological connection of a female sex hormone (progesterone) to onco-fetal immune tolerance via B7-H4 and suggests that the PR-P300-BRD4 axis is targetable for treating B7-H4+ cancer.

AChR-seropositive myasthenia gravis in muscular dystrophy: diagnostic pitfalls and clinical management challenges.

The co-occurrence of genetic myopathies with myasthenia gravis (MG) is extremely rare, however a few studies have been reported. We aim to explore the link between genetically inherited muscle disorders and immune-mediated neuromuscular junction conditions, taking into account the diagnostic and therapeutic implications posed by these combined conditions. We searched all English medical papers registered in Web of Knowledge, PubMed, Google Scholar, and Science Direct between January 1987 concerning the association between muscular dystrophies (MD) and MG, also adding three new cases to the series reported so far. Three new clinical cases in which MG concurs with oculopharyngeal muscular dystrophy (OPMD) or facioscapulohumeral muscular dystrophy (FSHD) or myotonic dystrophy type 2 (DM2) were reported. A comprehensive literature review showed that FSHD is the dystrophy most frequently associated with generalized MG. The AChR antibody titer is high and neurophysiologic tests prove to be an essential tool for the diagnosis. The association between MG and MD is rare but should not be underestimated. The presence of unusual clinical features suggest investigating additional overlapping condition, especially when a treatable disease like MG is suspected.

Re-establishing immune tolerance in multiple sclerosis: focusing on novel mechanisms of mesenchymal stem cell regulation of Th17/Treg balance.

The T-helper 17 (Th17) cell and regulatory T cell (Treg) axis plays a crucial role in the development of multiple sclerosis (MS), which is regarded as an immune imbalance between pro-inflammatory cytokines and the maintenance of immune tolerance. Mesenchymal stem cell (MSC)-mediated therapies have received increasing attention in MS research. In MS and its animal model experimental autoimmune encephalomyelitis, MSC injection was shown to alter the differentiation of CD4+T cells. This alteration occurred by inducing anergy and reduction in the number of Th17 cells, stimulating the polarization of antigen-specific Treg to reverse the imbalance of the Th17/Treg axis, reducing the inflammatory cascade response and demyelination, and restoring an overall state of immune tolerance. In this review, we summarize the mechanisms by which MSCs regulate the balance between Th17 cells and Tregs, including extracellular vesicles, mitochondrial transfer, metabolic reprogramming, and autophagy. We aimed to identify new targets for MS treatment using cellular therapy by analyzing MSC-mediated Th17-to-Treg polarization.

Temporal restriction of Cas9 expression improves CRISPR-mediated deletion efficacy and fidelity.

Clinical application of CRISPR-Cas9 technology for large deletions of somatic mutations is inefficient, and methods to improve utility suffer from our inability to rapidly assess mono- vs. biallelic deletions. Here we establish a model system for investigating allelic heterogeneity at the single-cell level and identify indel scarring from non-simultaneous nuclease activity at gRNA cut sites as a major barrier to CRISPR-del efficacy both in vitro and in vivo. We show that non-simultaneous nuclease activity is partially prevented via restriction of CRISPR-Cas9 expression via inducible adeno-associated viruses (AAVs) or lipid nanoparticles (LNPs). Inducible AAV-based expression of CRISPR-del machinery significantly improved mono- and biallelic deletion frequency in vivo, supporting the use of the Xon cassette over traditional constitutively expressing AAV approaches. These data depicting improvements to deletions and insight into allelic heterogeneity after CRISPR-del will inform therapeutic approaches for phenotypes that require either large mono- or biallelic deletions, such as autosomal recessive diseases or where mutant allele-specific gRNAs are not readily available, or in situations where the targeted sequence for excision is located multiple times in a genome.

Extracellular vesicles from seminal plasma interact with T cells in vitro and drive their differentiation into regulatory T-cells.

Seminal plasma induces immune tolerance towards paternal allogenic antigens within the female reproductive tract and during foetal development. Recent evidence suggests a role for extracellular vesicles in seminal plasma (spEVs). We isolated spEVs from seminal plasma that was donated by vasectomized men, thereby excluding any contributions from the testis or epididymis. Previous analysis demonstrated that such isolated spEVs originate mainly from the prostate. Here we observed that when isolated fluorescently labelled spEVs were mixed with peripheral blood mononuclear cells, they were endocytosed predominantly by monocytes, and to a lesser extent also by T-cells. In a mixed lymphocyte reaction, T-cell proliferation was inhibited by spEVs. A direct effect of spEVs on T-cells was demonstrated when isolated T cells were activated by anti-CD3/CD28 coated beads. Again, spEVs interfered with T cell proliferation, as well as with the expression of CD25 and the release of IFN-γ, TNF, and IL-2. Moreover, spEVs stimulated the expression of Foxp3 and IL-10 by CD4+CD25+CD127- T cells, indicating differentiation into regulatory T-cells (Tregs). Prior treatment of spEVs with proteinase K revoked their effects on T-cells, indicating a requirement for surface-exposed spEV proteins. The adenosine A2A receptor-specific antagonist CPI-444 also reduced effects of spEVs on T-cells, consistent with the notion that the development of Tregs and their immune suppressive functions are under the influence of adenosine-A2A receptor signalling. We found that adenosine is highly enriched in spEVs and propose that spEVs are targeted to and endocytosed by T-cells, after which they may release their adenosine content into the lumen of endosomes, thus allowing endosome-localized A2A receptor signalling in spEVs targeted T-cells. Collectively, these data support the idea that spEVs can prime T cells directly for differentiation into Tregs.

Optimizing oral immune tolerance to Type II collagen in patients with rheumatoid arthritis: The importance of dose, Interfering medication and Genetics.

OBJECTIVES: Oral immune tolerance (OT) is a complex process with unknown genetic regulation. Our aim is to explore possible genetic control of OT in patients with rheumatoid arthritis (RA). METHODS: RA patients with increased interferon γ production invitro when their isolated peripheral blood mononuclear cells (PBMC) were cultured with type II bovine collagen α1 chain [α1 (II)] were enrolled in this study and were randomly assigned to the "Low dose" type II collagen (CII) group (30 µg/day for 10 weeks, followed by 50 µg/day for 10 weeks, followed by 70 µg/day for 10 weeks) or "High dose" CII group (90 µg/day for 10 weeks, followed by 110 µg/day for 10 weeks, followed by 130 µg/day for 10 weeks). Heparinized blood was obtained at baseline and after each of the 10 weeks treatment for analysis of the invitro production of IFNγ by their PBMC stimulated by α1(II) . Single nucleotide polymorphism (SNP) analysis of the responders and non-responders to oral CII was conducted using GeneChip Mapping 10 K 2.0 Array. RESULTS: The SNP A-15,737 was found to associate with the ability of CII to suppress IFNγ production by α1(CII)-stimulated RA PBMC. The potential for SNP A-15,737 to associate with the OT response for patients with another autoimmune disease [OT induced by oral type I bovine collagen (CI) in patients with diffuse cutaneous systemic sclersodid (dsSSc)] was also explored. CONCLUSIONS: The ROT1 region plays a role in the control of IFNγ production after oral dosing of auto-antigens, thereby determining if oral tolerance to that antigen will develop.

Exploring the Impact of mRNA Modifications on Translation Efficiency and Immune Tolerance to Self-Antigens.

Therapeutic modified mRNAs are being developed for a broad range of human diseases. However, the impact of potential miscoding of modified mRNAs on self-tolerance remains unknown. Additionally, more studies are needed to explore the effects of nucleoside alkylation on translation. While all six tested modifications are tolerated as substrates by T7 RNA polymerase and inhibited mRNA immunogenicity, the translation efficiency varied significantly depending on the type of modification. In contrast to methylation, ethylation at the N1 position of pseudouridine (Ψ) hindered translation, suggesting that the C5-C1' glycosidic bond alone is not a critical element for high translation. Inhibition of mRNA translation was also observed with 5-methoxyuridine modification. However, this inhibition was partially alleviated through the optimization of mRNA coding sequences. BALB/c mice immunized with syngeneic ψ-modified mRNA encoding for Wilms' tumor antigen-1 (WT1) developed a low but significant level of anti-WT1 IgG antibodies compared to those immunized with either unmodified or N1-methyl ψ-modified mRNA. Overall, the data indicate that adding a simple ethyl group (-CH2CH3) at the N1 position of ψ has a major negative effect on translation despite its reduced immunogenicity. Additionally, mRNA containing Ψ may alter translation fidelity at certain codons, which could lead to a breakdown of immune tolerance to self-antigens. This concern should be taken into account during gene replacement therapies, although it could benefit mRNA-based vaccines by generating a diverse repertoire of antigens.

Gut microbiota from B-cell-specific TLR9-deficient NOD mice promote IL-10+ Breg cells and protect against T1D.

Introduction: Type 1 diabetes (T1D) is an autoimmune disease characterized by the destruction of insulin-producing ß cells. Toll-like receptor 9 (TLR9) plays a role in autoimmune diseases, and B cell-specific TLR9 deficiency delays T1D development. Gut microbiota are implicated in T1D, although the relationship is complex. However, the impact of B cell-specific deficiency of TLR9 on intestinal microbiota and the impact of altered intestinal microbiota on the development of T1D are unclear. Objectives: This study investigated how gut microbiota and the intestinal barrier contribute to T1D development in B cell-specific TLR9-deficient NOD mice. Additionally, this study explored the role of microbiota in immune regulation and T1D onset. Methods: The study assessed gut permeability, gene expression related to gut barrier integrity, and gut microbiota composition. Antibiotics depleted gut microbiota, and fecal samples were transferred to germ-free mice. The study also examined IL-10 production, Breg cell differentiation, and their impact on T1D development. Results: B cell-specific TLR9-deficient NOD mice exhibited increased gut permeability and downregulated gut barrier-related gene expression. Antibiotics restored gut permeability, suggesting microbiota influence. Altered microbiota were enriched in Lachnospiraceae, known for mucin degradation. Transferring this microbiota to germ-free mice increased gut permeability and promoted IL-10-expressing Breg cells. Rag-/- mice transplanted with fecal samples from Tlr9 fl/fl Cd19-Cre+ mice showed delayed diabetes onset, indicating microbiota's impact. Conclusion: B cell-specific TLR9 deficiency alters gut microbiota, increasing gut permeability and promoting IL-10-expressing Breg cells, which delay T1D. This study uncovers a link between TLR9, gut microbiota, and immune regulation in T1D, with implications for microbiota-targeted T1D therapies.

Elucidating the Mechanisms Underlying Interindividual Differences in the Onset of Adverse Drug Reactions.

Idiosyncratic drug toxicities (IDTs) pose a significant challenge; they are marked by life-threatening adverse reactions that emerge aftermarket release and are influenced by intricate genetic and environmental variations. Recent genome-wide association studies have highlighted a strong correlation between specific human leukocyte antigen (HLA) polymorphisms and IDT onset. This review provides an overview of current research on HLA-mediated drug toxicities. In the last six years, HLA-transgenic (Tg) mice have been instrumental in advancing our understanding of these underlying mechanisms, uncovering systemic immune reactions that replicate human drug-induced immune stimulation. Additionally, the potential role of immune tolerance in shaping individual differences in adverse effects highlights its relevance to the interplay between HLA polymorphisms and IDTs. Although HLA-Tg mice offer valuable insights into systemic immune reactions, further exploration is essential to decipher the intricate interactions that lead to organ-specific adverse effects, especially in organs such as the skin or liver. Navigating the intricate interplay of HLA, which may potentially trigger intracellular immune responses, this review emphasizes the need for a holistic approach that integrates findings from both animal models and molecular/cellular investigations. The overarching goal is to enhance our comprehensive understanding of HLA-mediated IDTs and identify factors shaping individual variations in drug reactions. This review aims to facilitate the development of strategies to prevent severe adverse effects, address existing knowledge gaps, and provide guidance for future research initiatives in the field of HLA-mediated IDTs.

Low-dose immune tolerance induction for severe hemophilia A inhibitor patients: Immunosuppressants are generally not necessary for inhibitor-titer below 200 BU/mL.

Importance: It remained unclear that the efficacy comparison between low-dose immune tolerance induction (LD-ITI) incorporating immunosuppressants (IS) when severe hemophilia A (SHA) patients had inhibitor-titer ≥200 Bethesda Units (BU)/mL (LD-ITI-IS200 regimen) and LD-ITI combining with IS when SHA patients had inhibitor-titer ≥40 BU/mL (LD-ITI-IS40 regimen). Objective: To compare the efficacy of the LD-ITI-IS200 regimen with that of the LD-ITI-IS40 regimen for SHA patients with high-titer inhibitors. Methods: A prospective cohort study on patients receiving LD-ITI-IS200 compared to those receiving LD-ITI-IS40 from January 2021 to December 2023. Both received LD-ITI [FVIII 50 IU/kg every other day]. IS (rituximab + prednisone) was added when peak inhibitor tier ≥200 BU/mL in the LD-ITI-IS200 regimen and ≥40 BU/mL in the LD-ITI-IS40 regimen. Success is defined as a negative inhibitor plus FVIII recovery ≥66% of the expected. Results: We enrolled 30 patients on LD-ITI-IS200 and 64 patients on LD-ITI-IS40, with similar baseline clinical characteristics. A lower IS-use rate was discovered in the LD-ITI-IS200 regimen compared to the LD-ITI-IS40 regimen (30.0% vs. 62.5%). The two regimens (LD-ITI-IS200 vs. LD-ITI-IS40) had similar success rate (70.0% vs. 79.7%), median time to success (9.4 vs. 10.6 months), and annualized bleeding rate during ITI (3.7 vs. 2.8). The cost to success was lower for LD-ITI-IS200 than for LD-ITI-IS40 (2107 vs. 3256 US Dollar/kg). Among patients with peak inhibitor-titer 40-199 BU/mL, 10 non-IS-using (on LD-ITI-IS200 regimen) and 28 IS-using (on LD-ITI-IS40 regimen) had similar success rates (70.0% vs. 78.6%) and time to success (9.0 vs. 8.8 months). Interpretation: In LD-ITI, IS are not necessary for inhibitor titer <200 BU/mL.

BMAL2 promotes eCIRP-induced macrophage endotoxin tolerance.

Background: The disruption of the circadian clock is associated with inflammatory and immunological disorders. BMAL2, a critical circadian protein, forms a dimer with CLOCK, activating transcription. Extracellular cold-inducible RNA-binding protein (eCIRP), released during sepsis, can induce macrophage endotoxin tolerance. We hypothesized that eCIRP induces BMAL2 expression and promotes macrophage endotoxin tolerance through triggering receptor expressed on myeloid cells-1 (TREM-1). Methods: C57BL/6 wild-type (WT) male mice were subjected to sepsis by cecal ligation and puncture (CLP). Serum levels of eCIRP 20 h post-CLP were assessed by ELISA. Peritoneal macrophages (PerM) were treated with recombinant mouse (rm) CIRP (eCIRP) at various doses for 24 h. The cells were then stimulated with LPS for 5 h. The levels of TNF-α and IL-6 in the culture supernatants were assessed by ELISA. PerM were treated with eCIRP for 24 h, and the expression of PD-L1, IL-10, STAT3, TREM-1 and circadian genes such as BMAL2, CRY1, and PER2 was assessed by qPCR. Effect of TREM-1 on eCIRP-induced PerM endotoxin tolerance and PD-L1, IL-10, and STAT3 expression was determined by qPCR using PerM from TREM-1-/- mice. Circadian gene expression profiles in eCIRP-treated macrophages were determined by PCR array and confirmed by qPCR. Induction of BMAL2 activation in bone marrow-derived macrophages was performed by transfection of BMAL2 CRISPR activation plasmid. The interaction of BMAL2 in the PD-L1 promoter was determined by computational modeling and confirmed by the BIAcore assay. Results: Serum levels of eCIRP were increased in septic mice compared to sham mice. Macrophages pre-treated with eCIRP exhibited reduced TNFα and IL-6 release upon LPS challenge, indicating macrophage endotoxin tolerance. Additionally, eCIRP increased the expression of PD-L1, IL-10, and STAT3, markers of immune tolerance. Interestingly, TREM-1 deficiency reversed eCIRP-induced macrophage endotoxin tolerance and significantly decreased PD-L1, IL-10, and STAT3 expression. PCR array screening of circadian clock genes in peritoneal macrophages treated with eCIRP revealed the elevated expression of BMAL2, CRY1, and PER2. In eCIRP-treated macrophages, TREM-1 deficiency prevented the upregulation of these circadian genes. In macrophages, inducible BMAL2 expression correlated with increased PD-L1 expression. In septic human patients, blood monocytes exhibited increased expression of BMAL2 and PD-L1 in comparison to healthy subjects. Computational modeling and BIAcore assay identified a putative binding region of BMAL2 in the PD-L1 promoter, suggesting BMAL2 positively regulates PD-L1 expression in macrophages. Conclusion: eCIRP upregulates BMAL2 expression via TREM-1, leading to macrophage endotoxin tolerance in sepsis. Targeting eCIRP to maintain circadian rhythm may correct endotoxin tolerance and enhance host resistance to bacterial infection.

Cellular pathways and molecular events that shape autoantibody production in COVID-19.

A hallmark of COVID-19 is the variety of complications that follow SARS-CoV-2 infection in some patients, and that target multiple organs and tissues. Also remarkable are the associations with several auto-inflammatory disorders and the presence of autoantibodies directed to a vast array of antigens. The processes underlying autoantibody production in COVID-19 have not been completed deciphered. Here, we review mechanisms involved in autoantibody production in COVID-19, multisystem inflammatory syndrome in children, and post-acute sequelae of COVID19. We critically discuss how genomic integrity, loss of B cell tolerance to self, superantigen effects of the virus, and extrafollicular B cell activation could underly autoantibody proaction in COVID-19. We also offer models that may account for the pathogenic roles of autoantibodies in the promotion of inflammatory cascades, thromboembolic phenomena, and endothelial and vascular deregulations.

High levels of anti-factor VIII immunoglobulin G4 and immunoglobulin G total are associated with immune tolerance induction failure in people with congenital hemophilia A and high-responding inhibitors.

Background: Immune tolerance induction (ITI) is the treatment of choice to eradicate neutralizing anti-factor (F)VIII alloantibodies (inhibitors) in people with inherited hemophilia A. However, it is not successful in 10% to 40% of the cases. The biological mechanisms and biomarkers associated with ITI outcome are largely unknown. Objectives: The aim of this study was to investigate the association of plasma cytokines (interferon-γ, tumor necrosis factor, interleukin [IL]-2, IL-4, IL-5, IL-6, IL-10, and IL-17A), chemokines (IL-8/CXCL8, RANTES/CCL5, MIG/CXCL9, MCP-1/CCL2, and IP-10/CXCL10), and anti-FVIII immunoglobulin (Ig) G total, IgG1, and IgG4 with ITI outcome. Methods: In this cross-sectional analysis of the Brazilian Immune Tolerance Study, we assessed plasma levels of anti-FVIII IgGs using an enzyme-linked immunosorbent assay with plasma-derived FVIII and recombinant FVIII as target antigens, immobilized in microplates. Results: We assayed 98 plasma samples of moderately severe and severe (FVIII activity, <2%) people with hemophilia A after completion of a first ITI course. Levels of anti-recombinant FVIII IgG total and IgG4 were higher in people with hemophilia A who failed ITI (IgG total optical density [OD], 0.37; IQR, 0.15-0.73; IgG4 OD, 2.19; IQR, 0.80-2.52) than in those who had partial (IgG total OD, 0.03; IQR, 0.00-0.14; IgG4 OD, 0.39; IQR, 0.09-1.11; P < .0001 for both) or complete success (IgG total OD, 0.04; IQR, 0.00-0.07; IgG4 OD, 0.07; IQR, 0.06-0.40; P < .0001 for both). Plasma cytokines, chemokines, and anti-FVIII IgG1 were not associated with ITI outcome. Conclusion: Our results show that high levels of plasma anti-FVIII IgG4 and IgG total are associated with ITI failure.

The role of aryl hydrocarbon receptors in nutrient metabolism and immune regulation at the maternal-fetal interface.

The maternal-fetal interface is composed of the placenta, which is affiliated with the fetus, and the maternal decidua. During pregnancy, the placenta is mainly responsible for nutrient transport and immune tolerance maintenance, which plays a key role in fetal growth and development and pregnancy maintenance. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that exists in various cell types at the maternal-fetal interface and is involved in multiple cellular processes. Recent studies have highlighted the role of AhR in regulating various physiological processes, including glucose and lipid metabolism, as well as tryptophan metabolism and immune responses, within non-pregnant tissues. This review shifts focus towards understanding how AhR modulation impacts metabolism and immune regulation at the maternal-fetal interface. This may implicate the development of pregnancy-related complications and the potential target of the AhR pathway for therapeutic strategies against poor pregnancy outcomes.

Microparticles incorporating dual apoptotic factors to inhibit anti-inflammatory effects in macrophages.

New approaches to treat autoimmune diseases are needed, and we can be inspired by mechanisms in immune tolerance to guide the design of these approaches. Efferocytosis, the process of phagocyte-mediated apoptotic cell (AC) disposal, represents a potent tolerogenic mechanism that we could draw inspiration from to restore immune tolerance to specific autoantigens. ACs engage multiple avenues of the immune response to redirect aberrant immune responses. Two such avenues are: phosphatidylserine on the outer leaflet of the cell and engaging the aryl hydrocarbon receptor (AhR) pathway. We incorporated these two avenues into one acetalated dextran (Ace-DEX) microparticle (MP) for evaluation in vitro. First phosphatidylserine (PS) was incorporated into Ace-DEX MPs and evaluated for cellular association and mediators of cell tolerance including IL-10 production and M2 associated gene expression when particles were cultured with peritoneal macrophages (PMacs). Further PS Ace-DEX MPs were evaluated as an agent to suppress LPS stimulated PMacs. Then, AhR agonist 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) was incorporated into Ace-DEX MPs and expression of M2 and IL-10 genes was evaluated in PMacs. Further the ITE and PS Ace-DEX MPs (PS/ITE MPs) were evaluated for suppression of T cell priming and Th1 polarization. Our results indicate that the PS/ITE-MPs stimulated anti-inflammatory cytokine expression and suppressed inflammation following LPS stimulation of PMacs. Moreover, PS/ITE MPs induced the anti-inflammatory enzyme IDO1 and suppressed macrophage-mediated T cell priming and Th1 polarization. These findings suggest that PS and ITE-loaded Ace-DEX MPs could be a promising therapeutic tool for suppressing inflammation.

The use of PD-1 functional knockout rats to study idiosyncratic adverse reactions to nevirapine.

Idiosyncratic drug reactions (IDRs) are associated with significant patient morbidity/mortality and lead to considerable drug candidate attrition in drug development. Their idiosyncratic nature makes the study of IDRs difficult. In particular, nevirapine is associated with a relatively high risk of serious skin rash and liver injury. We previously found that nevirapine causes a similar skin rash in female Brown Norway rats, but these animals do not develop significant liver injury. Programmed cell death protein-1 (PD-1) is an immune checkpoint involved in immune tolerance, and anti-PD-1 antibodies have been used to treat cancer. However, they increase the risk of liver injury caused by co-administered drugs. We found that PD-1-/- mice are more susceptible to drug-induced liver injury, but PD-1-/- mice are not a good model for all drugs. In particular, they do not develop a skin rash when treated with nevirapine, at least in part because they lack the sulfotransferase in their skin that forms the reactive metabolite responsible for the rash. Therefore, we developed a PD-1 mutant (PD-1m/m) rat, with an excision in the ligand-binding domain of PD-1, to test whether nevirapine would cause a more serious skin rash in these animals. The PD-1m/m rat was based on a Sprague Dawley background, which has a lower incidence of skin rash than Brown Norway rats. The treated PD-1m/m rats developed more severe liver injury than PD-1-/- mice, but in contrast to expectations, they did not develop a skin rash. Functional knockouts provide a unique tool to study the mechanisms of IDRs.

CD4+ T cell heterogeneity in gestational age and preeclampsia using single-cell RNA sequencing.

A balance between pro-inflammatory decidual CD4+ T cells and FOXP3+ regulatory T cells (FOXP3+ Tregs) is important for maintaining fetomaternal tolerance. Using single-cell RNA-sequencing and T cell receptor repertoire analysis, we determined that diversity and clonality of decidual CD4+ T cell subsets depend on gestational age. Th1/Th2 intermediate and Th1 subsets of CD4+ T cells were clonally expanded in both early and late gestation, whereas FOXP3+ Tregs were clonally expanded in late gestation. Th1/Th2 intermediate and FOXP3+ Treg subsets showed altered gene expression in preeclampsia (PE) compared to healthy late gestation. The Th1/Th2 intermediate subset exhibited elevated levels of cytotoxicity-related gene expression in PE. Moreover, increased Treg exhaustion was observed in the PE group, and FOXP3+ Treg subcluster analysis revealed that the effector Treg like subset drove the Treg exhaustion signatures in PE. The Th1/Th2 intermediate and effector Treg like subsets are possible inflammation-driving subsets in PE.

Maternal-fetal immunity and recurrent spontaneous abortion.

Recurrent Spontaneous Abortion (RSA) is a common pregnancy complication, that has multifactorial causes, and currently, 40%-50% of cases remain unexplained, referred to as Unexplained RSA (URSA). Due to the elusive etiology and mechanisms, clinical management is exceedingly challenging. In recent years, with the progress in reproductive immunology, a growing body of evidence suggests a relationship between URSA and maternal-fetal immunology, offering hope for the development of tailored treatment strategies. This article provides an immunological perspective on the pathogenesis, diagnosis, and treatment of RSA. On one hand, it comprehensively reviews the immunological mechanisms underlying RSA, including abnormalities in maternal-fetal interface immune tolerance, maternal-fetal interface immune cell function, gut microbiota-mediated immune dysregulation, and vaginal microbiota-mediated immune anomalies. On the other hand, it presents the diagnosis and existing treatment modalities for RSA. This article offers a clear knowledge framework for understanding RSA from an immunological standpoint. In conclusion, while the "layers of the veil" regarding immunological factors in RSA are gradually being unveiled, our current research may only scratch the surface. In terms of immunological etiology, effective diagnostic tools for RSA are currently lacking, and the efficacy and safety of immunotherapies, primarily based on lymphocyte immunotherapy and intravenous immunoglobulin, remain contentious.

Triptolide promotes differentiation of human monocytes into immunosuppressive MDSCs.

BACKGROUND: Myeloid-derived suppressor cells (MDSCs) negatively modulate immune activity. Prior investigations have shown much promise in using MDSCs-assisted immunotherapy for organ transplantation patients. Additionally, owing to its immunosuppressive activity, MDSCs can also be used to manage immune-associated disorders. METHODS: Granulocyte-macrophage colony-stimulating factor (GM-CSF) was employed to stimulate myeloid progenitor cell differentiation. Triptolide (PG490) was introduced toward the later phases of in vitro MDSCs induction. Lastly, real-time PCR (RT-PCR) and flow cytometry were used to assess transcript expression and cell phenotype, and a mouse skin transplantation model was established to evaluate the MDSCs-mediated immune suppression in vivo. RESULTS: Co-stimulation with PG490 and GM-CSF potently induced myeloid-derived monocytes to form MDSCs, with remarkable immune-suppressive activity. The underlying mechanism involved downregulation of T cell proliferation, activation, enhancement of inflammatory cytokine release, as well as T cell conversion to Treg cells. PG490 strongly enhanced iNOS expression in MDSCs, and iNOS inhibition successfully reversed the immune-suppression. The PG490- and GM-CSF-induced MDSCs substantially extended survival duration of murine skin grafts, thereby validating their strong immune-suppressive activity in vivo. CONCLUSIONS: Herein, we presented a new approach involving MDSCs-based immunosuppression in vitro. PG490 and GM-CSF co-treatment strongly induced immuno-suppressive activity in MDSCs both in vitro and in vivo. Our findings highlight the promise of applying MDSCs-based therapy in clinical organ transplantation treatment.