Emerging role of endosomal toll-like receptors in rheumatoid arthritis

Hyperresponsiveness of Corticoid-Resistant Th17/Tc-17 Cells to TLR-2 and TLR-4 Ligands is a Feature of Multiple Sclerosis Patients at Higher Risk of Therapy Failure

Purpose

The presence of T cells expressing TLR-2 and TLR-4 has been associated with relapsing-remitting multiple sclerosis (RRMS) pathogenesis. Here, we evaluated whether the effectiveness of DMT in controlling clinical activity of the disease would be associated with modulation of proportion of TLRs+ T cells.

Patients and Methods

Whole peripheral blood mononuclear cells, purified CD4+ and CD8+ T cells from RRMS patients were cultured with different stimuli. The frequency of IL-17-secreting CD4+ and CD8+ T cells positive for TLR-2 and TLR-4 was determined by flow cytometry. The cytokine profile of these T cells following TLR-2 and TLR-4 stimulation was determined by Multiplex. Some of these T cell cultures were treated with hydrocortisone. The levels of LPS-binding protein (LBP) were dosed by ELISA. Clinical (occurrence of relapses) and radiological (number of active brain lesions) activity were evaluated during the 1-year follow-up.

Results

Despite DMT, high intensity of TLR-2 and TLR-4 expression on (CD4+ and CD8+) T-cells, as well as the frequency of IL-17-secreting (CD4+ and CD8+) T-cells, are predictive of future RRMS relapses. Moreover, higher cytokine production related to Th17/Tc-17 phenotypes in response to TLR-2 and TLR-4 agonists was observed in DMT-treated patients and displayed an elevated number of brain lesions. The hyperresponsiveness of MS-derived T-cells to TLR-2 and TLR-4 ligands, with high levels of IL-1β, IL-6, IL-17, IFN-γ and GM-CSF in response to both TLR agonists, positively correlated with plasma LBP levels. Interestingly, corticoid was less efficient in reducing Th17 and Tc-17 cytokine production induced by TLR-2 and TLR-4 ligands in DMT-treated patients who relapsed during follow-up.

Conclusion

Collectively, the data suggested that persistence of circulating Th17 and Tc17 cells expressing elevated levels of functional TLR-2 and TLR-4 could indicate high disease activity and lower therapeutic efficacy in RRMS patients.

Hydroxychloroquine attenuates double-stranded RNA-stimulated hyper-phosphorylation of tristetraprolin/ZFP36 and AU-rich mRNA stabilization

The human innate immune system recognizes dsRNA as a pathogen-associated molecular pattern that induces a potent inflammatory response. The primary source of pathogenic dsRNA is cells infected with replicating viruses, but can also be released from uninfected necrotic cells. Here, we show that the dsRNA poly(I:C) challenge in human macrophages activates the p38 MAPK-MK2 signalling pathway and subsequently the phosphorylation of tristetraprolin (TTP/ZFP36). The latter is an mRNA decay-promoting protein that controls the stability of AU-rich mRNAs (AREs) that code for many inflammatory mediators. Hydroxychloroquine (HCQ), a common anti-malaria drug, is used to treat inflammatory and autoimmune disorders and, controversially, during acute COVID-19 disease. We found that HCQ reduced the dsRNA-dependent phosphorylation of p38 MAPK and its downstream kinase MK2. Subsequently, HCQ reduced the abundance and protein stability of the inactive (phosphorylated) form of TTP. HCQ reduced the levels and the mRNA stability of poly (I:C)-induced cytokines and inflammatory mRNAs like TNF, IL-6, COX-2, and IL-8 in THP-1 and primary blood monocytes. Our results demonstrate a new mechanism of the anti-inflammatory role of HCQ at post-transcriptional level (TTP phosphorylation) in a model of dsRNA activation, which usually occurs in viral infections or RNA release from necrotic tissue.

Chemical synthesis and immunological evaluation of cancer vaccines based on ganglioside antigens and α-galactosylceramide

iNKT cells - often referred as the "Swiss Army knife" of the immune system - have emerged as central players in cancer vaccine therapies. Glycolipids activating iNKT cells, such as α-galactosylceramide (αGalCer), can enhance the immune response against co-delivered cancer antigens and have been applied in the design of self-adjuvanting anti-tumor vaccines. In this context, this work focuses on the chemical synthesis of ganglioside tumor-associated carbohydrate antigens (TACAs), namely GM3 and (Neu5Gc)GM3 antigens, their conjugation to αGalCer, and their formulation into liposomes as an efficient platform for their in vivo delivery. Liposomes containing GM3-αGalCer, (Neu5Gc)GM3-αGalCer, and equimolar amounts of the two conjugates have been fully characterized and their ability to activate iNKT cell has been confirmed ex vivo in mouse and human cell assays. The candidates were tested in in vivo immunization studies, demonstrating an ability to induce both TH1 and TH2 cytokines leading to the production of all subclasses of IgG antibodies. Notably, the study also demonstrated that serum antibodies raised against the two TACAs, alone and in combination, were cross-reactive. This finding has consequences for future vaccine designs - even if a highly tumor-selective antigen is chosen, the resulting antibody response may be broader than anticipated.

Selection and characterization of a peptide-based complement modulator targeting C1 of the innate immune system

The human complement pathway plays a pivotal role in immune defence, homeostasis, and autoimmunity regulation, and complement-based therapeutics have emerged as promising interventions, with both antagonistic and agonistic approaches being explored. The classical pathway of complement is initiated when the C1 complex binds to hexameric antibody platforms. Recent structural data revealed that C1 binds to small, homogeneous interfaces at the periphery of the antibody platforms. Here, we have developed a novel strategy for complement activation using macrocyclic peptides designed to mimic the interface between antibodies and the C1 complex. In vitro selection utilizing the RaPID system identified a cyclic peptide (cL3) that binds to the C1 complex via the globular head domains of C1q. Notably, when immobilized on surfaces, cL3 effectively recruits C1 from human serum, activates C1s proteases, and induces lysis of cell-mimetic lipid membranes. This represents the first instance of a peptide capable of activating complement by binding C1 when immobilized. Further characterization and synthesis of deletion mutants revealed a critical cycle size of cL3 essential for C1 binding and efficient complement activation. Importantly, cL3 also demonstrated the ability to inhibit complement-mediated lysis without affecting C1 binding, highlighting its potential as a therapeutic modality to prevent complement-dependent cytotoxicity whilst promoting cellular phagocytosis and cell clearance. In summary, this study introduces the concept of "Peptactins" - peptide-based activators of complement - and underscores the potential of macrocyclic peptides for complement modulation, offering potential advantages over traditional biologicals in terms of size, production, and administration.

Modulation of plasmacytoid dendritic cells response in inflammation and autoimmunity

The discovery of toll-like receptors (TLRs) and the subsequent recognition that endogenous nucleic acids (NAs) could serve as TLR ligands have led to essential insights into mechanisms of healthy immune responses as well as pathogenic mechanisms relevant to systemic autoimmune and inflammatory diseases. In systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis, NA-containing immune complexes serve as TLR ligands, with distinct implications depending on the additional immune stimuli available. Plasmacytoid dendritic cells (pDCs), the robust producers of type I interferon (IFN-I), are providing critical insights relevant to TLR-mediated healthy immune responses and tissue repair, as well as generation of inflammation, autoimmunity and fibrosis, processes central to the pathogenesis of many autoimmune diseases. In this review, we describe recent data characterizing the role of platelets and NA-binding chemokines in modulation of TLR signaling in pDCs, as well as implications for how the IFN-I products of pDCs contribute to the generation of inflammation and wound healing responses by monocyte/macrophages. Chemokine modulators of TLR-mediated B cell tolerance mechanisms and interactions between TLR signaling and metabolic pathways are also considered. The modulators of TLR signaling and their contribution to the pathogenesis of systemic autoimmune diseases suggest new opportunities for identification of novel therapeutic targets.

Multiphoton lithography with protein photoresists

Recently, 2D/3D direct laser writing has attracted increased attention due to its broad applications ranging from biomedical engineering to aerospace. 3D nanolithography of water-soluble protein-based scaffolds have been envisioned to provide a variety of tunable properties. In this paper, we present a functional protein-based photoresist with tunable mechanical properties that is suitable for multiphoton lithography (MPL). Through the use of methacrylated streptavidin or methacrylated bovine serum albumin in combination with polyethylene glycol diacrylate or methacrylated hyaluronic acid as crosslinkers and a vitamin-based photoinitiator, we were able to write two- and three-dimensional structures as small as 200 nm/600 nm lateral/axial features, respectively. We also demonstrated that Young's modulus can be tuned by the photoresist composition, and we were able to achieve values as low as 40 kPa. Furthermore, we showed that Young's modulus can be recovered after drying and rehydration (i.e. shelf time determination). The retained biological functionality of the streptavidin scaffolds was demonstrated using fluorescently labelled biotins. Using single-molecule fluorescence microscopy, we estimated the density of streptavidin in the written features (1.8 ± 0.2 × 105 streptavidins per 1.00 ± 0.05 μm³ of feature volume). Finally, we showed applicability of our 2D scaffold as a support for a fluorescence absorbance immuno-assay (FLISA), and as a delivery platform of extracellular vesicles to HeLa cells.

The exploration of glucocorticoid pathway based on disease severity in COVID-19 patients

Systemic inflammation is a hallmark of Coronavirus Disease 2019 (COVID-19) and is the key to the pathophysiology of its severe cases with host cytokine involvement. Glucocorticoids can moderate this inflammatory effect due to receptor binding (NRC31-the gene encoded), influencing the expression of effector genes and pro-inflammatory cytokines. Another important pathway in the processes of the immune and inflammatory responses is nuclear factor-κB (NF-κB) signaling (NFKBIA-the gene encoded). We aimed to explore the expression of genes in the glucocorticoid pathway in mild and severe COVID-19. We performed a cross-sectional, observational study on COVID-19 cases, assessing the expression of RNA in white blood cells. The Illumina® platform was used for RNA sequencing, and FASTQ data were quality-checked with Multiqc. The raw data were analyzed using CLC Genomics Workbench®. Our study included 23 patients with severe COVID-19 and 21 patients with mild COVID-19 with an average age of 49.9 ± 18.2 years old. The NR3C1 and NFKBIA expressions did not show a significantly significant difference between groups (log2 fold change 0.5, p = 0.1; 0.82, p = 0.09). However, the expressions of TSC22D3, DUSP-1, JAK-1 and MAPK-1 were significantly higher in mild cases (log2 fold change 1.3, p < 0.001; 2.6, p < 0.001; 0.9, p < 0.001; 1.48, p-value<0.001; respectively). Furthermore, the TNF, IL-1β, and IL-6 expressions were significantly lower in mild cases (log2 fold change 4.05, p < 0.001; 3.33, p < 0.001; 6.86, p < 0.001; respectively). In conclusion, our results showed that although the NRC31 and NFKBIA expressions did not show a statistically significant difference between groups, the expression of TSC22D3 was higher in mild cases. These results highlight the importance of effector genes, specifically TSC22D3, in combatting systemic inflammation. Our recent findings have the potential to lead to the identification of novel pharmacological targets that could prove to be vital in the fight against diseases associated with inflammation.

S, K.K. J, R. U, T.V. A, G. R, V.B. SK, Asaf M, Sebastian R. Role of microRNA, bta-miR-375 in Immune Sturdiness of Vechur: The Native Cattle Breed of Kerala, India

In the present study, next generation sequencing was employed to identify and explore the differential expression profiles of microRNAs (miRNAs) in peripheral blood mononuclear cells (PBMCs) of crossbred (B. taurus x B. indicus) and Vechur (B. indicus) cattle in response to the bacterial endotoxin-lipopolysaccharide (LPS). The PBMCs from adult apparently healthy female crossbred cows and Vechur cattle, a native cattle breed of Kerala, India were stimulated with 10 μg/mL of LPS for 6 h. Among the differentially expressed miRNAs, the expression of 13 miRNAs showed statistically significant up regulation while, significant decrease in the expression of 15 miRNAs was noticed in LPS treated PBMCs of Vechur cattle compared to crossbred cows. The expression profiling of miRNA, bta-miR-375, expression of which was found to be significantly down regulated in LPS treated PBMCs of Vechur cattle with respect to crossbred cattle by the NGS studies, is presented in the present manuscript. The decrease in expression of bta-miR-375 noticed by NGS was in accordance with the results of quantitative real time PCR assay. Functional gene enrichment analysis and pathway analysis revealed significant enrichment of predicted targets of bta-miR-375 in many immune related and cell signalling mechanisms. In addition, over representation of targets of bta-miR-375 was also noticed in pathogenesis of many of the bovine diseases. The study could also identify differences in the expression of cytokines, viz. Tumour Necrosis Factor Alpha (TNFα), Interleukin 4 (IL-4) and Interferon-γ (IFNγ) between LPS treated and untreated PBMCs of crossbred and Vechur cattle.

A potential therapeutic target: The role of neutrophils in the central nervous system

Neutrophils play a critical role in immune defense as the first recruited and most abundant leukocytes in the innate immune system. As such, regulation of neutrophil effector functions have strong implications on immunity. These cells display a wide heterogeneity of function, including both inflammatory and immunomodulatory roles. Neutrophils commonly infiltrate the central nervous system (CNS) in response to varied pathological conditions. There is still little understanding of the role these cells play in the CNS in such conditions. In the present review, we will summarize what is known of neutrophil's role in cancer and Alzheimer's disease (AD), with a focus on highlighting the gaps in our understanding.

Targeting Lymph Nodes for Systemic Immunosuppression Using Cell-Free-DNA-Scavenging And cGAS-Inhibiting Nanomedicine-In-Hydrogel for Rheumatoid Arthritis Immunotherapy

Rheumatoid arthritis (RA) is a systemic autoimmune disease with pathogenic inflammation caused partly by excessive cell-free DNA (cfDNA). Specifically, cfDNA is internalized into immune cells, such as macrophages in lymphoid tissues and joints, and activates pattern recognition receptors, including cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS), resulting in overly strong proinflammation. Here, nanomedicine-in-hydrogel (NiH) is reported that co-delivers cGAS inhibitor RU.521 (RU) and cfDNA-scavenging cationic nanoparticles (cNPs) to draining lymph nodes (LNs) for systemic immunosuppression in RA therapy. Upon subcutaneous injection, NiH prolongs LN retention of RU and cNPs, which pharmacologically inhibit cGAS and scavenged cfDNA, respectively, to inhibit proinflammation. NiH elicits systemic immunosuppression, repolarizes macrophages, increases fractions of immunosuppressive cells, and decreases fractions of CD4+ T cells and T helper 17 cells. Such skewed immune milieu allows NiH to significantly inhibit RA progression in collagen-induced arthritis mice. These studies underscore the great potential of NiH for RA immunotherapy.

Effects of glutamine and arginine combination on pro- and anti-inflammatory cytokines

Background

Cytokines were beneficial for diagnosis and treatment, which in clinical situations introduced from the perspective of pro and anti-inflammatory effects. An inflammatory response is commonly associated with various severe traumatic insults that consequently recruit the immune cells into the target organs and causing systemic inflammatory response that can lead to sepsis. Immune-modulating nutrients, such as glutamine and arginine, are known as pathophysiological modulate in inflammation.

Aim

The aim of this study was to evaluate the effect of oral gavage supplementation with a combination of glutamine and arginine on inflammatory cytokines in intestinal mucosa, specifically jejunum.

Methods

Sixteen Rattus norvegicus rats (average weight 150-200 g) were randomly divided into two groups: groups A and B, both intraperitoneal injected by 2 ml NaCl 0.9%. Group A orally supplemented with 1 ml dextrose 5% daily, meanwhile, group B orally supplemented with 1 ml combination of glutamine and arginine (contains 250 mg/kg glutamine and 250 mg/kg arginine) daily. The experiment lasted for 3 days. We compared the pro and anti-inflammatory cytokines (IL-10, NF-κB, TNF-α, IL-8, and MMP-8) between the two groups by the Mann-Whitney test.

Results

More IL-10, TNF-α, and IL-8 cytokine-produced cells found in group A. Group B produced significantly lower TNF-α (p = 0.009) and IL-8 (p = 0.003). The number of NF-κB and MMP-8 were slightly higher in group B.

Conclusion

Giving a combination of glutamine and arginine as nutrition supplementation has beneficial effects in decreasing almost half of the cells that produce TNF-α and IL-8. Further studies must be carried out to support a standard guideline for this recommendation.

Cytokine profiling of samples positive for Chlamydia trachomatis and Human papillomavirus

Persistent human papillomavirus (HPV) infection is closely associated with cervical carcinoma. Co-infection in the endocervical environment with other microorganisms, such as Chlamydia trachomatis, may increase the risk of HPV infection and neoplastic progression. While in some individuals, Chlamydia trachomatis infection is resolved with the activation of Th1/IFN-γ-mediated immune response, others develop a chronic infection marked by Th2-mediated immune response, resulting in intracellular persistence of the bacterium and increasing the risk of HPV infection. This work aimed to quantify cytokines of the Th1/Th2/Th17 profile in exfoliated cervix cells (ECC) and peripheral blood (PB) of patients positive for Chlamydia trachomatis DNA, patients positive for Papillomavirus DNA, and healthy patients. Cytokine levels were quantified by flow cytometry in ECC and PB samples from patients positive for C. trachomatis DNA (n = 18), patients positive for HPV DNA (n = 30), and healthy patients (n = 17) treated at the Hospital de Amor, Campo Grande-MS. After analysis, a higher concentration of IL-17, IL-6, and IL-4 (p <0.05) in ECC; INF-γ and IL-10 (p <0.05) in PB was found in samples from patients positive for C. trachomatis DNA compared to samples from healthy patients. When comparing samples from patients positive for HPV DNA, there was a higher concentration of cytokines IL-17, IL-10, IL-6, and IL-4 (p <0.05) in ECC and IL-4 and IL-2 (p <0.05) in PB of patients positive for C. trachomatis DNA. These results suggest that induction of Th2- and Th17 mediated immune response occurs in patients positive for C. trachomatis DNA, indicating chronic infection. Our results also demonstrate a high concentration of pro-inflammatory cytokines in ECC of patients positive for C. trachomatis DNA.

Electroacupuncture Alleviates Pain Responses and Inflammation in Collagen-Induced Arthritis Rats via Suppressing the TLR2/4-MyD88-NF-κB Signaling Pathway

Results

EA intervention and OxPAPC injection could relieve mechanical allodynia and thermal hyperalgesia caused by CIA. Paw edema and pathological damage of synovium were significantly ameliorated after EA intervention and OxPAPC injection. Furthermore, EA intervention and OxPAPC injection markedly reduced the contents of serum TNF-α, IL-1β, and IL-6, as well as the protein expression levels of synovial TLR2, TLR4, MyD88, and NF-κB p-p65. In particular, the expression of TLR2 and TLR4 on synovial fibroblasts and macrophages in synovium was significantly reduced by EA intervention.

Conclusions

Repeated EA stimulation at ST36 and SP6 can effectively relieve joint pain and synovial inflammation caused by RA in CIA rats. The analgesic and anti-inflammatory effect of EA may be closely related to the inhibition of innate immune responses driven by the TLR2/4-MyD88-NF-κB signaling pathway in the synovium.

In vitro and in silico analysis of 'Taikong blue' lavender essential oil in LPS-induced HaCaT cells and RAW264.7 murine macrophages

BACKGROUND

'Taikong blue' lavender, a space-bred cultivar of Lavandula angustifolia, is one of the main lavender essential oil production crops in Xinjiang Province, China. Several cases of local usage indicated that 'Taikong blue' lavender essential oil (TLEO) had excellent anti-inflammatory and antioxidant properties for skin problems. However, to date, substantial data on these functions are lacking. In this study, we aimed to investigate the composition and bioactivities of TLEO and the potential underlying mechanisms through LPS-induced inflammatory models of HaCaT and RAW264.7 cells.

METHODS

The composition of TLEO was determined by GC‒MS. To study the anti-inflammatory and antioxidative properties of TLEO, we induced HaCaT and RAW264.7 cells by LPS. TLEO (0.001%-0.1%, v/v) was used to treat inflamed cells with dexamethasone (DEX, 10 μg/mL) as the standard drug. A variety of tests were carried out, including biochemical assays, ELISA, RT‒PCR, and western blotting. Docking of components was performed to predict potential ligands.

RESULTS

The GC‒MS analysis revealed that 53 compounds (> 0.01%) represented 99.76% of the TLEO, and the majority of them were esters. TLEO not only reduced the levels of oxidative stress indicators (NO, ROS, MDA, and iNOS at the mRNA and protein levels) but also protected the SOD and CAT activities. According to the RT‒PCR, ELISA, and Western blot results, TLEO decreased inflammation by inhibiting the expression of TNF-α, IL-1β, IL-6, and key proteins (IκBα, NF-кB p65, p50, JNK, and p38 MAPK) in MAPK-NF-кB signaling. Molecular docking results showed that all of the components (> 1% in TLEO) were potent candidate ligands for further research.

CONCLUSION

The theoretical evidence for TLEO in this study supported its use in skin care as a functional ingredient for cosmetics and pharmaceutics.

Altered Fc glycosylation of anti-HLA alloantibodies in hemato-oncological patients receiving platelet transfusions

BACKGROUND

The formation of alloantibodies directed against class I human leukocyte antigens (HLA) continues to be a clinically challenging complication after platelet transfusions, which can lead to platelet refractoriness (PR) and occurs in approximately 5%-15% of patients with chronic platelet support. Interestingly, anti-HLA IgG levels in alloimmunized patients do not seem to predict PR, suggesting functional or qualitative differences among anti-HLA IgG. The binding of these alloantibodies to donor platelets can result in rapid clearance after transfusion, presumably via FcγR-mediated phagocytosis and/or complement activation, which both are affected by the IgG-Fc glycosylation.

OBJECTIVES

To characterize the Fc glycosylation profile of anti-HLA class I antibodies formed after platelet transfusion and to investigate its effect on clinical outcome.

PATIENTS/METHODS

We screened and captured anti-HLA class I antibodies (anti-HLA A2, anti-HLA A24, and anti-HLA B7) developed after platelet transfusions in hemato-oncology patients, who were included in the PREPAReS Trial. Using liquid chromatography-mass spectrometry, we analyzed the glycosylation profiles of total and anti-HLA IgG1 developed over time. Subsequently, the glycosylation data was linked to the patients' clinical information and posttransfusion increments.

RESULTS

The glycosylation profile of anti-HLA antibodies was highly variable between patients. In general, Fc galactosylation and sialylation levels were elevated compared to total plasma IgG, which correlated negatively with the platelet count increment. Furthermore, high levels of afucosylation were observed for two patients.

CONCLUSIONS

These differences in composition of anti-HLA Fc-glycosylation profiles could potentially explain the variation in clinical severity between patients.

Host-pathogen protein-nucleic acid interactions: A comprehensive review

Recognition of pathogen-derived nucleic acids by host cells is an effective host strategy to detect pathogenic invasion and trigger immune responses. In the context of pathogen-specific pharmacology, there is a growing interest in mapping the interactions between pathogen-derived nucleic acids and host proteins. Insight into the principles of the structural and immunological mechanisms underlying such interactions and their roles in host defense is necessary to guide therapeutic intervention. Here, we discuss the newest advances in studies of molecular interactions involving pathogen nucleic acids and host factors, including their drug design, molecular structure and specific patterns. We observed that two groups of nucleic acid recognizing molecules, Toll-like receptors (TLRs) and the cytoplasmic retinoic acid-inducible gene (RIG)-I-like receptors (RLRs) form the backbone of host responses to pathogen nucleic acids, with additional support provided by absent in melanoma 2 (AIM2) and DNA-dependent activator of Interferons (IFNs)-regulatory factors (DAI) like cytosolic activity. We review the structural, immunological, and other biological aspects of these representative groups of molecules, especially in terms of their target specificity and affinity and challenges in leveraging host-pathogen protein-nucleic acid interactions (HP-PNI) in drug discovery.

CXCL4 synergizes with TLR8 for TBK1-IRF5 activation, epigenomic remodeling and inflammatory response in human monocytes

Regulation of endosomal Toll-like receptor (TLR) responses by the chemokine CXCL4 is implicated in inflammatory and fibrotic diseases, with CXCL4 proposed to potentiate TLR responses by binding to nucleic acid TLR ligands and facilitating their endosomal delivery. Here we report that in human monocytes/macrophages, CXCL4 initiates signaling cascades and downstream epigenomic reprogramming that change the profile of the TLR8 response by selectively amplifying inflammatory gene transcription and interleukin (IL)-1β production, while partially attenuating the interferon response. Mechanistically, costimulation by CXCL4 and TLR8 synergistically activates TBK1 and IKKε, repurposes these kinases towards an inflammatory response via coupling with IRF5, and activates the NLRP3 inflammasome. CXCL4 signaling, in a cooperative and synergistic manner with TLR8, induces chromatin remodeling and activates de novo enhancers associated with inflammatory genes. Our findings thus identify new regulatory mechanisms of TLR responses relevant for cytokine storm, and suggest targeting the TBK1-IKKε-IRF5 axis may be beneficial in inflammatory diseases.

Infiltrating natural killer cells bind, lyse and increase chemotherapy efficacy in glioblastoma stem-like tumorospheres

Glioblastomas remain the most lethal primary brain tumors. Natural killer (NK) cell-based therapy is a promising immunotherapeutic strategy in the treatment of glioblastomas, since these cells can select and lyse therapy-resistant glioblastoma stem-like cells (GSLCs). Immunotherapy with super-charged NK cells has a potential as antitumor approach since we found their efficiency to kill patient-derived GSLCs in 2D and 3D models, potentially reversing the immunosuppression also seen in the patients. In addition to their potent cytotoxicity, NK cells secrete IFN-γ, upregulate GSLC surface expression of CD54 and MHC class I and increase sensitivity of GSLCs to chemotherapeutic drugs. Moreover, NK cell localization in peri-vascular regions in glioblastoma tissues and their close contact with GSLCs in tumorospheres suggests their ability to infiltrate glioblastoma tumors and target GSLCs. Due to GSLC heterogeneity and plasticity in regards to their stage of differentiation personalized immunotherapeutic strategies should be designed to effectively target glioblastomas.

“Super-charged” NK cells kill patient-derived glioblastoma stem-like cells (GSLCs) in 2D and 3D tumor models, secrete IFN-γ and upregulate the surface expression of CD54 and MHC class I in GSLCs.

Delineating the role of osteoprotegerin as a marker of breast cancer risk among women with a BRCA1 mutation

Women with a pathogenic germline mutation in the BRCA1 gene face a very high lifetime risk of developing breast cancer, estimated at 72% by age 80. Prophylactic bilateral mastectomy is the only effective way to lower their risk; however, most women with a mutation opt for intensive screening with annual MRI and mammography. Given that the BRCA1 gene was identified over 20 years ago, there is a need to identify a novel non-surgical approach to hereditary breast cancer prevention. Here, we provide a review of the emerging preclinical and epidemiologic evidence implicating the dysregulation of progesterone-mediated receptor activator of nuclear factor κB (RANK) signaling in the pathogenesis of BRCA1-associated breast cancer. Experimental studies have demonstrated that RANK inhibition suppresses Brca1-mammary tumorigenesis, suggesting a potential target for prevention. Data from studies conducted among women with a BRCA1 mutation further support this pathway in BRCA1-associated breast cancer development. Progesterone-containing (but not estrogen-alone) hormone replacement therapy is associated with an increased risk of breast cancer in women with a BRCA1 mutation. Furthermore, BRCA1 mutation carriers have significantly lower levels of circulating osteoprotegerin (OPG), the decoy receptor for RANK-ligand (RANKL) and thus endogenous inhibitor of RANK signaling. OPG levels may be associated with the risk of disease, suggesting a role of this protein as a potential biomarker of breast cancer risk. This may improve upon current risk prediction models, stratifying women at the highest risk of developing the disease, and further identify those who may be targets for anti-RANKL chemoprevention. Collectively, the evidence supports therapeutic inhibition of the RANK pathway for the primary prevention of BRCA1-associated breast cancer, which may generate unique prevention strategies (without prophylactic surgery) and enhance quality of life.

The Genetic Association Between TLR-1, -2, -4, and -6 Gene Polymorphisms and Rheumatoid Arthritis Susceptibility in a Chinese Han Population

Aims: The toll-like receptor (TLR) genes were shown to be involved in the pathogenesis of rheumatoid arthritis (RA). We aimed to investigate the genetic associations between the TLR-1, -2, -4, and -6 genes polymorphisms and RA susceptibility in a Chinese Han population. Methods: Six polymorphisms [TLR-1 (rs5743610, rs5743618), -2 (rs5743708), -4 (rs4986790, rs4986791), and -6 (rs5743810)] in TLRs genes were genotyped in 360 patients with RA and 560 matched healthy controls by using direct sequencing method. The odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated using a standard logistic regression analysis. Results: No significant association between the allelic, dominant, and recessive models of TLR-1 rs5743610, TLR-2 rs5743708, TLR-4 rs4986790 and rs4986791, and TLR-6 rs5743810 polymorphisms and RA risk was observed (p > 0.05). However, significant associations were detected between the allelic, dominant, and recessive models of TLR-1 rs5743618 and RA risk (allelic: OR [95% CI] = 2.21 [1.73-2.81], p < 0.0001; dominant: OR [95% CI] = 2.33 [1.75-3.09], p < 0.0001; recessive models: OR [95% CI] = 3.70 [1.85-7.41], p = 0.0002). In addition, the TLR6 rs5743810 was found to be associated with the rheumatoid factor (RF)^- and anticyclic citrullinated peptide (anti-CCP)^- antibody in RA group (RF: OR [95% CI] = 2.29 [1.42-3.69], p = 0.0007; anti-CCP: OR [95% CI] = 2.33 [1.39-3.89], p = 0.001). Conclusions: The allelic, dominant, and recessive models of TLR1 rs5743618 might be associated with RA susceptibility. Also, the TLR6 rs5743810 might be associated with RF and anti-CCP antibody of RA in Chinese Han population.

AMP5A modulates Toll-like receptors 7 and 8 single-stranded RNA immune responses in PMA-differentiated THP-1 and PBMC

BACKGROUND

Dysregulation of antiviral immunity has been implicated in the progression of acute respiratory syndrome coronavirus 2 infection into severe cases of coronavirus disease of 2019 (COVID-19). Imbalances in the inflammatory response drive the overabundant production of pro-inflammatory cytokines and chemokines. The low molecular weight fraction of 5% human serum albumin commercial preparation (AMP5A) is a novel biologic drug currently under clinical investigation for the treatment of osteoarthritis and the hyperinflammatory response associated with COVID-19. This study aims to elucidate AMP5A effects following the activation of immune cells with agonists of Toll-like receptor (TLR) 7 and/or 8, which detect ssRNA viral sequences.

METHODS

CXCL10 ELISAs were used to evaluate the dynamics of myeloid cells activated with CL075 and CL307, agonists of TLR7/8 and TLR7, respectively. In addition, enrichment analysis of gene sets generated by ELISA arrays was utilized to gain insight into the biologic processes underlying the identified differentially expressed cytokine profiles. Finally, relative potency (REP) was employed to confirm the involvement of mechanisms of action paramount to AMP5A activity.

RESULTS

AMP5A inhibits the release of CXCL10 from both CL075- and CL307-activated PMA-differentiated THP-1 and peripheral blood mononuclear cells. Furthermore, AMP5A suppresses a distinct set of pro-inflammatory cytokines (including IL-1β, IL-6, IL-12, and CXCL10) associated with COVID-19 and pro-inflammatory NF-κB activation. REP experiments using antagonists specific for the immunomodulatory transcription factors, peroxisome proliferator-activated receptor γ, and aryl hydrocarbon receptor, also indicate that these pathways are involved in the ability of AMP5A to inhibit CXCL10 release.

CONCLUSION

Due to the biphasic course of COVID-19, therapeutic approaches that augment antiviral immunity may be more beneficial early in infection, whereas later interventions should focus on inflammation suppression. In this study, we show that AMP5A inhibits TLR 7/8 signaling in myeloid cells, resulting in a decrease in inflammatory mediators associated with hyperinflammation and autoimmunity. Furthermore, data demonstrating that AMP5A activates immunomodulatory transcription factors found to be protective in lung disease is provided. These findings suggest that the modes and mechanisms of action of AMP5A are well suited to treat conditions involving dysregulated TLR 7/8 activation.

Effect of multi-epitope derived from HIV-1 on REM sleep deprivation-induced spatial memory impairment with respect to the level of immune factors in mice

Objectives

Sleep deprivation (SD) has a negative impact on cognitive functions including learning and memory. Many studies have shown that rapid-eye-movement (REM) SD also disrupts memory performance. In this study, we aimed to investigate the effect of multi-epitope Gag-Pol-Env-Tat derived from Human immunodeficiency virus 1 (HIV-1) on REM SD-induced spatial memory impairment with respect to the levels of interleukin-4 (IL-4), interleukin-17 (IL-17), interferon-gamma (IFN-γ), immunoglobulin G1 (IgG1), immunoglobulin G2a (IgG2a), and lymphocyte proliferation in NMRI mice. We used multi-epitope Gag-Pol-Env-Tat derived from HIV-1 because Gag-Pol-Env-Tat immunogen sequence is one of the most sensitive immunogen sequences of HIV-1 that can significantly augment cellular and humoral immune systems, leading to the improvement of cognitive functions.

Materials and Methods

Morris water maze apparatus was used to assess spatial memory, and multi-platform apparatus was used to induce RSD for 24 hr. Multi-epitope derived from HIV-1 was subcutaneously injected at the dose of 20 µgr/ml, once and fourteen days before RSD.

Results

RSD impaired spatial memory and injection of multi-epitope derived from HIV-1 reversed this effect. RSD decreased IL-4, IgG1, and IgG2a levels, while multi-epitope derived from HIV-1 reversed these effects. Multi-epitope derived from HIV-1 also increased lymphocyte proliferation and decreased IL-17 levels in both control and RSD mice.

Conclusion

Multi-epitope derived from HIV-1 may improve memory performance via induction of anti-inflammatory immune response.

MiR-27a-3p Targets GLP1R to Regulate Differentiation, Autophagy, and Release of Inflammatory Factors in Pre-Osteoblasts via the AMPK Signaling Pathway

Objective: Osteoporosis is caused by the dysregulation of bone homeostasis which is synergistically mediated by osteoclasts and osteoblasts. MiR-27a-3p is a key inhibitor of bone formation. Hence, unearthing the downstream target gene of miR-27a-3p is of great significance to understand the molecular mechanism of osteoporosis. Methods: Bioinformatics analysis was utilized to find the downstream target gene of miR-27a-3p, and dual-luciferase reporter assay was conducted to validate the interplay of miR-27a-3p and GLP1R. Besides, qRT-PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA) were employed to verify the impact of miR-27a-3p on GLP1R expression and the differentiation, autophagy, and inflammatory response of MC3T3-E1 pre-osteoblasts. Results: Dual-luciferase assay validated that miR-27a-3p directly targeted GLP1R. Additionally, posttreatment of MC3T3-E1 cells with miR-27a-3p mimics resulted in a remarkable decrease in expression levels of GLP1R, cell differentiation marker gene, autophagy marker gene, and AMPK. These results indicated that miR-27a-3p targeted GLP1R to inhibit AMPK signal activation and pre-osteoblast differentiation and autophagy, while promoting the release of inflammatory factors. Conclusion: The miR-27a-3p/GLP1R regulatory axis in pre-osteoblasts contributes to understanding the molecular mechanism of osteoporosis.

Progress and challenges for the machine learning-based design of fit-for-purpose monoclonal antibodies

Although the therapeutic efficacy and commercial success of monoclonal antibodies (mAbs) are tremendous, the design and discovery of new candidates remain a time and cost-intensive endeavor. In this regard, progress in the generation of data describing antigen binding and developability, computational methodology, and artificial intelligence may pave the way for a new era of in silico on-demand immunotherapeutics design and discovery. Here, we argue that the main necessary machine learning (ML) components for an in silico mAb sequence generator are: understanding of the rules of mAb-antigen binding, capacity to modularly combine mAb design parameters, and algorithms for unconstrained parameter-driven in silico mAb sequence synthesis. We review the current progress toward the realization of these necessary components and discuss the challenges that must be overcome to allow the on-demand ML-based discovery and design of fit-for-purpose mAb therapeutic candidates.

Effects of a polyherbal formulation on inflammation and histopathological alterations in mice with ovalbumin-induced allergic asthma

OBJECTIVE

Allergic asthma is a complex inflammatory disorder that affects the airways. As an ancient medical system, Iranian Traditional Medicine (ITM) recommends a polyherbal formula called "Monzej-e-balgham" for the treatment of asthma. In the present investigation, the antiasthmatic effects of "Monzej-e-balgham" were examined in a murine model of allergic asthma.

MATERIALS AND METHODS

Twenty-eight Balb/c mice weighing 15-20 g were allocated into 4 groups. As negative and positive controls, groups I and II received phosphate-buffered saline (PBS) and ovalbumin (OVA) solutions, respectively. Groups III and IV were first sensitized with OVA and then respectively treated with "Monzej-e-balgham" (63 mg/kg) and budesonide. Finally, bronchoalveolar lavage fluid (BALF) and lung tissues of the animals were collected and used for eosinophil counting, Th2 type interleukins (IL-5, IL-13, and IL-33) measurement, and histological examinations.

RESULTS

"Monzej-e-balgham" significantly reduced the number of eosinophils and the levels of IL-5, IL-13, and IL-33 in BALF specimens compared to OVA-sensitized group (p<0.05). It also ameliorated histopathological changes of the lung tissues such as goblet cells hyperplasia and mucus overproduction in comparison to group II. Interestingly, the results of the "Monzej-e-balgham"-treated group were comparable with those obtained for budesonide-inhaled mice.

CONCLUSION

The present data indicated a mechanism that involves Th2 inflammatory responses in allergic asthma and suggested a polyherbal mixture for the treatment of this disease.

Identification of Tumor Necrosis Factor-Alpha (TNF-α) Inhibitor in Rheumatoid Arthritis Using Network Pharmacology and Molecular Docking

Background: This study aimed to investigate the molecular mechanism of Radix Paeoniae Alba (white peony, WP) in treating immune inflammatory diseases of rheumatoid arthritis (RA) and tumor necrosis factor-alpha (TNF-α) inhibitors (TNFis) by using network pharmacology and molecular docking. Methods: In this study, the ingredient of WP and the potential inflammatory targets of RA were obtained from the Traditional Chinese Medicine Systematic Pharmacology Database, GeneCard, and OMIM databases, respectively. The establishment of the RA-WP-potential inflammatory target gene interaction network was accomplished using the STRING database. Network maps of the WP-RA-potential inflammatory target gene network were constructed using Cytoscape software. Gene ontology (GO) and the biological pathway (KEGG) enrichment analyses were used to further explore the RA mechanism and therapeutic effects of WP. Molecular docking technology was used to analyze the optimal effective components from WP for docking with TNF-α. Results: Thirteen active ingredients and 71 target genes were screened from WP, and 49 of the target genes intersected with RA target inflammatory genes and were considered potential therapeutic targets. Network pharmacological analysis showed that the WP active ingredients such as mairin, DPHCD, (+)-catechin, beta-sitosterol, paeoniflorin, sitosterol, and kaempferol showed better correlation with RA inflammatory target genes such as PGR, PTGS1, PTGS2, NR3C2, TNFSF15, and CHRM2, respectively. The immune-inflammatory signaling pathways of the active ingredients for the treatment of RA are the TNF-α signaling pathway, Toll-like receptor signaling pathway, cell apoptosis, interleukin-17 signaling pathway, C-type lectin receptor signaling pathway, mitogen-associated protein kinase, etc. Molecular docking results suggested that mairin was the most appropriate natural TNFis. Conclusion: Our findings provide an essential role and basis for further immune-inflammatory studies into the molecular mechanisms of WP and TNFis development in RA.

Recent trends in the development of Toll-like receptor 7/8-targeting therapeutics

Introduction: Toll-like receptor (TLR) 7 and TLR8 are functionally localized to endosomes and recognize specific RNA sequences. They play crucial roles in initiating innate and adaptive immune responses. TLR7/8 activation protects the host against invading pathogens and enhances immune responses. In contrast, sustained TLR7/8 signaling leads to immune overreaction. Therefore, agonists or antagonists targeting TLR7/8 signaling are favorable drug candidates for the treatment of immune disorders.Areas covered: Basic knowledge about TLR7 and TLR8 and their signaling pathways are briefly reviewed. Various therapeutic agents have been designed to activate or antagonize TLR7/8 signaling pathways, and their safety and efficacy for the treatment of multiple diseases have been investigated in preclinical animal models and clinical trials. TLR7/8 agonists exhibit potent antiviral activity and regulate anti-tumor immune responses. TLR7 agonists have also been used as adjuvants to improve vaccine immunogenicity and generate greater seroprotection. TLR7/8 antagonists are promising candidates for the treatment of autoimmune and inflammatory diseases.Expert opinion: TLR7/8 pathways are favorable targets for immunological therapies. Future research should concentrate on the optimization of drug safety, efficiency, and specificity. Detailed mechanistic studies will contribute to the development of TLR7/8 immunomodulators and novel therapeutic strategies.

Selective serotonin reuptake inhibitor attenuates the hyperresponsiveness of TLR2+ and TLR4+ Th17/Tc17-like cells in multiple sclerosis patients with major depression

Elevated frequency of Th17-like cells expressing Toll-like receptors (TLRs) has been recently associated with relapsing-remitting multiple sclerosis (MS) pathogenesis, a chronic inflammatory demyelinating autoimmune disease of the central nervous system. We aimed to investigate the impact of current major depressive disorder (MDD) on the behaviour of these cells following in vitro stimulation with TLR2, TLR4, TLR5 and TLR9 agonists. Here, the level of both cell proliferation and cytokine production related to Th17/Tc17 phenotypes in response to TLR2 (Pam3C) and TLR4 (LPS) ligands was significantly higher in CD4+ and CD8+ T-cell cultures from MS/MDD patients when compared to non-depressed patients. These cytokine levels were positively associated with neurological disabilities in patients. No difference for responsiveness to TLR5 (flagellin) and TLR9 (ODN) agonists was observed. LPS, but not Pam3C, induced significant IL-10 release, mainly in patients without MDD. Interestingly, more intense expression of TLR2 and TLR4 on these cells was observed in MDD patients. Finally, in vitro addition of serotonin and treatment of MDD patients with selective serotonin reuptake inhibitors (SSRIs) reduced the production of Th17/Tc17-related cytokines by CD4+ and CD8+ T cells in response to Pam3C and LPS. However, only SSRI therapy diminished the frequency and intensity of TLR2 and TLR4 expression on circulating CD4+ and CD8+ T cells. In summary, although preliminary, our findings suggest that adverse events that elevate circulating levels of TLR2 and TLR4 ligands can affect MS pathogenesis, particularly among depressed patients.

Epigenetic regulation of RNA sensors: Sentinels of immune response

Living host system possess mechanisms like innate immune system to combat against inflammation, stress singling, and cancer. These mechanisms are initiated by PAMP and DAMP mediated recognition by PRR. PRR is consist of variety of nucleic acid sensors like-RNA sensors. They play crucial role in identifying exogenous and endogenous RNA molecules, which subsequently mediate pro/inflammatory cytokine, IFN and ISGs response in traumatized or tumorigenic conditions. The sensors can sensitize wide range of nucleic acid particle in term of size and structure, while each category sensors belongs subclasses with differentially expressed in cell and distinguished functioning mechanisms. They are also able to make comparison between self and non-self-nucleic acid molecules through specific mechanisms. Besides exhibiting anti-inflammatory and anti-tumorigenic responses, RNA sensors cover the broad spectrum of response mechanisms. Transcriptionally RNA sensors undergo with tight epigenetic regulations. In this review study, we will be going to discuss about the details of RNA sensors, their functional mechanisms and epi-transactional regulations.

An Immuno-Clinic score model for evaluating T cell immunity and predicting early antiviral therapy effectiveness in chronic hepatitis B

We generated an Immuno-Clinic score (ICS) model to evaluate T cell immunity based on the clustering of antiviral cytokines and inhibitory molecules in 229 naïve chronic hepatitis B (CHB) patients. 126 patients receiving antiviral therapy were used to validate the model for predicting antiviral therapy effectiveness. Through receiver-operator characteristic curve analysis, the area under the curve, sensitivity, and specificity of the ICS model were 0.801 (95%CI 0.703-0.900), 0.727, and 0.722, respectively. The cut-off value was 0.442. Re-evaluation of T cell immunity in different phases of CHB showed that patients in the immune tolerant phase had the lowest percentage of ICS-high (15%), while patients in the inactive carrier phase had the highest percentage of ICS-high (92%). Patients in the immune active and gray zone phases had 17% and 56% ICS-high, respectively. Elevation of ICS as early as four weeks after treatment could predict the effectiveness of hepatitis B virus (HBV) DNA loss and normalization of alanine aminotransferase, while eight weeks after treatment could predict HBV surface antigen decline. Thus, this ICS model helps clinicians choose an optimal time for initiating antiviral therapy and predicting its efficacy.

Gene Expression and RNA Splicing Imputation Identifies Novel Candidate Genes Associated with Osteoporosis

CONTEXT

Though genome-wide association studies (GWASs) have identified hundreds of genetic variants associated with osteoporosis related traits, such as bone mineral density (BMD) and fracture, it remains a challenge to interpret their biological functions and underlying biological mechanisms.

OBJECTIVE

Integrate diverse expression quantitative trait loci and splicing quantitative trait loci data with several powerful GWAS datasets to identify novel candidate genes associated with osteoporosis.

DESIGN, SETTING, AND PARTICIPANTS

Here, we conducted a transcriptome-wide association study (TWAS) for total body BMD (TB-BMD) (n = 66 628 for discovery and 7697 for validation) and fracture (53 184 fracture cases and 373 611 controls for discovery and 37 857 cases and 227 116 controls for validation), respectively. We also conducted multi-SNP-based summarized mendelian randomization analysis to further validate our findings.

RESULTS

In total, we detected 88 genes significantly associated with TB-BMD or fracture through expression or ribonucleic acid splicing. Summarized mendelian randomization analysis revealed that 78 of the significant genes may have potential causal effects on TB-BMD or fracture in at least 1 specific tissue. Among them, 64 genes have been reported in previous GWASs or TWASs for osteoporosis, such as ING3, CPED1, and WNT16, as well as 14 novel genes, such as DBF4B, GRN, TMUB2, and UNC93B1.

CONCLUSIONS

Overall, our findings provide novel insights into the pathogenesis mechanisms of osteoporosis and highlight the power of a TWAS to identify and prioritize potential causal genes.

Targeting the TLR signalosome with TIR domain-derived cell-permeable decoy peptides: the current state and perspectives

The ability to engineer pharmaceuticals that target the signal-dependent interactions of signaling proteins should revolutionize drug development. One approach to the rational design of protein interaction inhibitors uses decoy peptides, i.e. segments of protein primary sequence, which are derived from interfaces that mediate functional protein interactions. Decoy peptides often retain the ability of the full-length prototype to bind the docking site of the folded protein and thereby block the signal transduction. This review summarizes advances made in the last decade in the development of cell-permeable decoy peptide (CPDP) inhibitors to target the Toll/IL-1R resistance (TIR) domain-mediated protein interactions in TLR signaling, in connection with the recent progress in understanding of the TLR signalosome assembly mechanisms. We present a large collection of currently available, TIR-targeting CPDPs and propose their classification based on the types of TIR–TIR interactions they target. The binding behavior of different CPDP-TIR pairs, studied in cell-based assays and in binary in vitro systems using recombinant TIR domains, is also reviewed. The available affinity data provide benchmarks for rapid preliminary evaluation of future inhibitors. We review literature that evaluates the in vivo potency of select CPDPs and attempt to outline the areas of forthcoming progress, towards the development of CPDP-based TLR inhibitors of pharmaceutical grade.

Mucosal IgG in inflammatory bowel disease - a question of (sub)class?

Immunoglobulins (Igs) form a cornerstone of mucosal immunity. In the gastrointestinal tract, secretory IgA and IgM bind to commensal microorganisms within the intestinal lumen to prevent them from breaching the intestinal epithelium - a process known as immune exclusion. In recent years, there has been renewed interest in the role of IgG in intestinal immunity, driven in part by a genetic association of an affinity-lowering variant of an IgG receptor, FcγRIIA, with protection from ulcerative colitis (UC), a subclass of inflammatory bowel disease (IBD). We recently demonstrated a role for IgG and Fcγ receptor signalling in driving pathogenic IL-1β production by colonic mononuclear phagocytes and the subsequent induction of a local type 17 response in UC. Here, we discuss the potential relevance of our observations to the other major subclass of IBD - Crohn's disease (CD) - where the genetic association with FCGR variants is less robust and consider how this may impact therapeutic interventions in these disease subsets.

Molecular effects and retinopathy induced by hydroxychloroquine during SARS-CoV-2 therapy: Role of CYP450 isoforms and epigenetic modulations

Antimalaria drugs such as chloroquine (CQ) and hydroxychloroquine (HCQ) have been administered to several inflammatory diseases including rheumatoid arthritis and systemic lupus erythematosus, and infectious diseases such as acquired immune deficiency syndrome and influenza. Recently, several patients infected with novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were given HCQ, and showed a discrepant response. HCQ inhibits SARS-CoV-2 cell entry, and inflammatory cascade by interfering with lysosomal and endosomal activities, and autophagy, impeding virus-membrane fusion, and inhibiting cytokine production resulted from inflammatory pathways activation. Despite ongoing administration of HCQ in a wide spectrum of disorders, there are some reports about several side effects, especially retinopathy in some patients treated with HCQ. Cytochrome P450 (CYP450) and its isoforms are the main metabolizers of HCQ and CQ. Pharmacokinetic properties of CYP enzymes are influenced by CYP polymorphism, non-coding RNAs, and epigenetic mechanisms such as DNA methylation, and histone acetylation. Accumulating evidence about side effects of HCQ in some patients raise the possibility that different response of patients to HCQ might be due to difference in their genome. Therefore, CYP450 genotyping especially for CYP2D6 might be helpful to refine HCQ dosage. Also, regular control of retina should be considered for patients under HCQ treatment. The major focus of the present review is to discuss about the pharmacokinetic and pharmacodynamic properties of CQ and HCQ that may be influenced by epigenetic mechanisms, and consequently cause several side effects especially retinopathy during SARS-CoV-2 therapy.

Association among cytokine profiles of innate and adaptive immune responses and clinical-virological features in untreated patients with chronic hepatitis B

Background

Complete clearance of intracellular viruses depends on effector cells of innate and adaptive immune systems. This study aimed to identify the relationships among antiviral cytokines produced by natural killer (NK) and T cells and clinical-virological characteristics in untreated chronic hepatitis B (CHB) patients.

Methods

We measured antiviral cytokines interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and interleukin-2 (IL-2) produced by T, NK and natural killer T (NKT) cells, respectively, in a cohort with chronic hepatitis B virus (HBV) infection (CHB). We also correlated these cytokines with clinical-virological characteristics using a linear regression model.

Results

levels of IFN-γ⁺ and TNF-α⁺ CD4⁺ and CD8⁺ T cells were significantly higher in immune active (IA) phase than in other phases. Immune tolerant (IT) patients showed the lowest expression of IFN-γ by NK and NKT cells, and TNF-α by NK cells. IFN-γ⁺, TNF-α⁺ and IL-2⁺ CD4⁺ and CD8⁺ T cells frequencies were similar between IA and gray zone (GZ) phases. Principal component analysis based on cytokines confirmed that most IT patients significantly differed from inactive carriers (IC) and IA patients, while GZ patients were widely scattered. Multivariate analysis showed both T and NK cells producing IFN-γ and TNF-α, but not IL-2, had significant association with serum alanine aminotransferase (ALT). Moreover, IFN-γ⁺ NKT cells were associated with HBV DNA, while IFN-γ⁺ CD4⁺ and CD8⁺ T cells were correlated with age.

Conclusion

HBV clinical phases are characterized by distinct cytokine signatures, which showed relationship to viral features in these untreated CHB patients.

Differentially Expressed Genes of Natural Killer Cells Can Distinguish Rheumatoid Arthritis Patients from Healthy Controls

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases, while its molecular triggers are not fully understood. A few studies have shown that natural killer (NK) cells may play either a pathogenic or a protective role in RA. In this study, we sought to explore NK cell markers that could be plausibly used in evaluating the differences among healthy controls and RA patients. Publicly available transcriptome datasets from RA patients and healthy volunteers were analyzed, in order to identify differentially expressed genes (DEGs) between 1. different immune cells as compared to NK cells, and 2. NK cells of RA patients and healthy controls. The identified DEGs were validated using 16 healthy controls and 17 RA patients. Peripheral blood mononuclear cells (PBMCs) were separated by Ficoll density gradient method, while NK cells were isolated using RosetteSep technique. RNA was extracted and gene expression was assessed using RT-qPCR. All selected genes were differentially expressed in NK cells compared to PBMCs. CD56, CXCL16, PECAM-1, ITGB7, BTK, TLR10, and IL-1β were significantly upregulated, while CCL2, CCR4, RELA and IBTK were downregulated in the NK cells of RA patients when compared to healthy controls. Therefore, these NK specific genes might be used as promising biomarkers for RA diagnosis.

Enhanced Expression of TLR8 in Placental Tissue in Preeclampsia

The expression of TLR8 in the placental tissue was studied in specimens from women of reproductive age with early- and late-onset preeclampsia (12 and 8 patients, respectively). The reference groups included 15 women: 10 with uneventful full-term pregnancy and 5 with preterm operative delivery on gestation weeks 28-33. The expression of TLR8 in placental structures was maximum in early-onset preeclampsia (p<0.01) characterized by the gravest clinical course, while the expression of TLR8 in late-onset preeclampsia was comparable with that in full-term pregnancy. This significant increase of TLR8 expression in placental tissue seemed to reflect activation of the key proinflammatory factors of congenital immunity and induction of the systemic inflammatory response. Manifest differences in the expression of TLR8 in late- and early-onset preeclampsia confirmed the hypothesis on different variants of this condition.

Receptor targeting drug delivery strategies and prospects in the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic inflammatory disease, is characterized by cartilage damage, bone tissue destruction, morphological changes in synovial fluids, and synovial joint inflammation. The inflamed synovial tissue has potential for passive and active targeting because of enhanced permeability and retention effect and the existence of RA synovial macrophages and fibroblasts that selectively express surface receptors such as folate receptor β, CD44 and integrin αVβ. Although there are numerous interventions in RA treatment, they are not safe and effective. Therefore, it is important to develop new drug or drug delivery systems that specifically targets inflamed/swollen joints but attenuates other possible damages to healthy tissues. Recently some receptors such as toll-like receptors (TLRs), the nucleotide-binding oligomerization domain-like receptors, and Fc-γ receptor have been identified in synovial tissue and immune cells that are involved in induction or suppression of arthritis. Analysis of the TLR pathway has moreover suggested new insights into the pathogenesis of RA. In the present paper, we have reviewed drug delivery strategies based on receptor targeting with novel ligand-anchored carriers exploiting CD44, folate and integrin αVβ as well as TLRs expressed on synovial monocytes and macrophages and antigen presenting cells, for possible active targeting in RA. TLRs could not only open a new horizon for developing new drugs but also their antagonists or humanized monoclonal antibodies that block TLRS specially TLR4 and TLR9 signaling could be used as targeting agents to antigen presenting cells and dendritic cells. As a conclusion, common conventional receptors and multifunctional ligands that arte involved in targeting receptors or developing nanocarriers with appropriate ligands for TLRs can provide profoundly targeting drug delivery systems for the effective treatment of RA.

The indications and safety of polyvalent immunoglobulin for post-exposure prophylaxis of hepatitis A, rubella and measles

Derived from pooled blood donations, polyvalent immunoglobulins are used for post-exposure prophylaxis as one aspect of the public health management of hepatitis A, rubella and measles. This review summarizes the safety profile of these blood products and the current recommendations for their use for the prevention of hepatitis A, rubella and measles among people who have been exposed to these diseases. The current recommendations are drawn from the most recent publicly available national guidelines of the United States, Australia, New Zealand, Canada and the United Kingdom as accessed in February 2019.

Direct Engagement of TLR9 Ligand with T Helper Cells Leads to Cell Proliferation & Up-regulation of Cytokines

PURPOSE

Toll like receptor (TLR) engagement is primarily a function of the innate immune cells. The purpose of the study was to assess direct uptake of ODN 2216 in T helper cells and effects on cell proliferation and cytokine expression.

METHODS

We isolated CD4+ CD25- T helper cells by magnetic sorting and studied the uptake of ODN 2216 using flow cytometry and confocal microscopy. We then studied the effect of ODN 2216 engagement on cell proliferation and cytokine expression using flow cytometry and gene expression of TLR9 signaling genes using real time RT-PCR.

RESULTS

We made a chance observation that purified T helper cells from healthy individuals consistently bind to the TLR9 ligand ODN 2216. In PBMCs, on the other hand, 98% of monocytes preferentially bound to ODN 2216 FITC, indicating that they competed with the lymphocytes. We confirmed intracellular localization of ODN 2216 FITC as well as intracellular expression of TLR9 in Thelper cells. Furthermore, ODN 2216 FITC was also co-localized with the lysosomal membrane associated protein 1. The uptake of TLR9 ligand culminated in cellular proliferation, up-regulation of cytokines and increased mRNA expression of TLR9 and IRF7 in T helper cells, in the absence of antigen presenting cells. ODN 2216 uptake was inhibited by promethazine as well as by TLR9 antagonist.

CONCLUSIONS

Our results show a direct engagement of TLR9 ligand in T helper cells and suggest involvement of TLR9 signalling in CD4+T cells, which may envisage novel targets for TLR inhibitors.

Lichen planus: altered AIM2 and NLRP1 expression in skin lesions and defective activation in peripheral blood mononuclear cells

BACKGROUND

Lichen planus (LP) is an inflammatory skin disease with unknown aetiology. Activation by pathogen-associated molecular patterns or environmental stimuli may activate some components of inflammasomes that contribute to the inflammatory process in LP lesions.

AIM

To characterize the inflammasomes in skin lesions and peripheral blood mononuclear cells (PBMCs) of patients with LP under Toll-like receptor (TLR) activation.

METHODS

In total, 15 patients with LP and 14 healthy controls (HCs) were enrolled in the study. Inflammasome expression in skin was evaluated by real-time PCR and immunohistochemistry, while ELISA was used to assess the production of interleukin (IL)-1β by PBMCs under stimulation with TLR4 and TLR7/TLR8 agonists and adenosine triphosphate (ATP).

RESULTS

Compared with the levels in HC samples, increased expression of the inflammasome AIM2 was verified in both epidermal and dermal sections of LP skin lesions, whereas NLRP1 and IL-β expression levels were enhanced in the dermis. LP skin lesion samples exhibited higher AIM2 transcript levels, similar NLRP1 levels and lower pro-IL-1β mRNA levels compared with HC samples. We verified that, compared with PBMCs from HC subjects, PBMCs from patients with LP produced similar amounts of IL-1β after induction by TLR4 agonists but lower IL-1β levels after induction by TLR7/TLR8 agonists, regardless of the addition of ATP.

CONCLUSION

Alterations in innate immunity, such as inflammasome component expression in skin lesions and PBMCs, were observed in patients with LP. Further investigations of dysfunctional inflammasome activation and the chronic inflammatory status of LP are required.

Spherical Nucleic Acid Nanoparticles: Therapeutic Potential

Spherical nucleic acids (SNAs) are highly oriented, well organized, polyvalent structures of nucleic acids conjugated to hollow or solid core nanoparticles. Because they can transfect many tissue and cell types without toxicity, induce minimum immune response, and penetrate various biological barriers (such as the skin, blood-brain barrier, and blood-tumor barrier), they have become versatile tools for the delivery of nucleic acids, drugs, and proteins for various therapeutic purposes. This article describes the unique structures and properties of SNAs and discusses how these properties enable their application in gene regulation, immunomodulation, and drug and protein delivery. It also summarizes current efforts towards clinical translation of SNAs and provides an expert opinion on remaining challenges to be addressed in the path forward to the clinic.

Hydroxychloroquine efficiently suppresses inflammatory responses of human class-switched memory B cells via Toll-like receptor 9 inhibition

Hydroxychloroquine is widely used for autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. Although B cells contribute to the pathogenesis of these diseases, the action of hydroxychloroquine on B cells remains unclear. Here we examined the effects of hydroxychloroquine on functions of B cell subsets. Hydroxychloroquine efficiently inhibited the mammalian target of rapamycin complex 1, differentiation of CD19⁺IgD^-CD27⁺ class-switched memory B cells to plasmablasts and their IgG production, under stimulation with CpG, a Toll-like receptor (TLR)-9 ligand. Hydroxychloroquine also inhibited CpG-induced production of interleukin-6 and tumor necrosis factor-α in B cell subsets. Taken together, hydroxychloroquine markedly suppresses the TLR9-mediated human B cell functions during inflammatory processes. Based on our results, we believe that hydroxychloroquine can be beneficial in the treatment of B cell-mediated autoimmune diseases.

Blocking TIR Domain Interactions in TLR9 Signaling

Interaction of TLR9 with ligands activates NF-κB, leading to proinflammatory cytokine production. Excessive TLR activation is a pathogenic factor for inflammatory diseases. This study has examined cell-permeating decoy peptides (CPDPs) derived from the TLR9 Toll/IL-1R resistance (TIR) domain. CPDP 9R34, which included AB loop, β-strand B, and N-terminal BB loop residues, inhibited TLR9 signaling most potently. CPDPs derived from α-helices C, D, and E (i.e., 9R6, 9R9, and 9R11) also inhibited TLR9-induced cytokines but were less potent than 9R34. 9R34 did not inhibit TLR2/1, TLR4, or TLR7 signaling. The N-terminal deletion modification of 9R34, 9R34-ΔN, inhibited TLR9 as potently as the full length 9R34. Binding of 9R34-ΔN to TIR domains was studied using cell-based Förster resonance energy transfer/fluorescence lifetime imaging approach. Cy3-labeled 9R34-ΔN dose-dependently decreased fluorescence lifetime of TLR9 TIR-Cerulean (Cer) fusion protein. Cy3-9R34-ΔN also bound TIRAP TIR, albeit with a lesser affinity, but not MyD88 TIR, whereas CPDP from the opposite TIR surface, 9R11, bound both adapters and TLR9. i.p. administration of 9R34-ΔN suppressed oligonucleotide-induced systemic cytokines and lethality in mice. This study identifies a potent, TLR9-specific CPDP that targets both receptor dimerization and adapter recruitment. Location of TIR segments that represent inhibitory CPDPs suggests that TIR domains of TLRs and TLR adapters interact through structurally homologous surfaces within primary receptor complex, leading to formation of a double-stranded, filamentous structure. In the presence of TIRAP and MyD88, primary complex can elongate bidirectionally, from two opposite ends, whereas in TIRAP-deficient cells, elongation is unidirectional, only through the αE side.