Interferon-λ enhances adaptive mucosal immunity by boosting release of thymic stromal lymphopoietin.

Interferon-λ (IFN-λ) acts on mucosal epithelial cells and thereby confers direct antiviral protection. In contrast, the role of IFN-λ in adaptive immunity is far less clear. Here, we report that mice deficient in IFN-λ signaling exhibited impaired CD8+ T cell and antibody responses after infection with a live-attenuated influenza virus. Virus-induced release of IFN-λ triggered the synthesis of thymic stromal lymphopoietin (TSLP) by M cells in the upper airways that, in turn, stimulated migratory dendritic cells and boosted antigen-dependent germinal center reactions in draining lymph nodes. The IFN-λ-TSLP axis also boosted production of the immunoglobulins IgG1 and IgA after intranasal immunization with influenza virus subunit vaccines and improved survival of mice after challenge with virulent influenza viruses. IFN-λ did not influence the efficacy of vaccines applied by subcutaneous or intraperitoneal routes, indicating that IFN-λ plays a vital role in potentiating adaptive immune responses that initiate at mucosal surfaces.

Sleep deprivation reduced LPS-induced IgG2b production by up-regulating BMAL1 and CLOCK expression.

Sleep deprivation (SD) weakens the immune system and leads to increased susceptibility to infectious or inflammatory diseases. However, it is still unclear how SD affects humoral immunity. In the present study, sleep disturbance was conducted using an sleep deprivation instrument, and the bacterial endotoxin lipopolysaccharide (LPS) was used to activate the immune response. It was found that SD-pretreatment reduced LPS-induced IgG2b+ B cells and IgG2b isotype antibody production in lymphocytes of spleen. And, SD-pretreatment decreased the proportion of CD4+T cells, production of CD4+T cells derived TGF-ß1 and its contribution in helping IgG2b production. Additionally, BMAL1 and CLOCK were selectively up-regulated in lymphocytes after SD. Importantly, BMAL1 and CLOCK deficiency contributed to TGF-ß1 expression and production of IgG2b+ B cells. Thus, our results provide a novel insight to explain the involvement of BMAL1 and CLOCK under SD stress condition, and their roles in inhibiting TGF-ß1 expression and contributing to reduction of LPS induced IgG2b production.

Evaluating the conduct and reporting of the T-cell dependent antibody response in the Extended One-Generation Reproductive Toxicity study provided under the EU REACH regulation.

The European Union (EU) Chemicals Strategy for Sustainability regards chemicals that affect the immune system among the most harmful ones. The Extended One-Generation Reproductive Toxicity study (EOGRTS; Organisation for Economic Co-Operation and Development (OECD) Test Guideline (TG) 443), addresses, among others, potential effects of chemicals on development. In specific cases, the EOGRTS is performed with addition of a so-called cohort 3, that addresses potential effects on the developing immune system, by means of a central assay measuring the T-cell dependent antibody response (TDAR). This assay is based on an interplay of antigen presentation, T-cell help and antibody production by B-cells, and together comprises a functional immune response. In the context of the EOGRTS review project of the European Chemicals Agency (ECHA), we evaluated 15 available TDARs for compliance with conduct and reporting requirements. Collectively, the majority of the TDAR studies were considered to be adequately conducted. We however observed: (i) the protocols differed by the antigen used (sheep red blood cells (SRBC) or KLH), the route of administration (intravenous, intraperitoneal, or subcutaneous), prime or prime/boost immunizations, and whether IgG was measured. (ii) There was major variation in the effects of the positive control for immunosuppression, cyclophosphamide. (iii) Proficiency was not always shown. (iv) Statistical analysis was not always done or reported. (v) Results of effects on lymphocyte populations or other immunotoxicity observations obtained in cohort 1 (or 2) of the EOGRTS were not always discussed together with results of the TDAR. Taken together, next to an improved quality of reporting, this may suggest a need to better define the conduct of the TDAR in OECD TG 443 and OECD Guidance Document (GD) 151, at least for certain aspects.

Inhibition of elastase enhances the adjuvanticity of alum and promotes anti-SARS-CoV-2 systemic and mucosal immunity.

Alum, used as an adjuvant in injected vaccines, promotes T helper 2 (Th2) and serum antibody (Ab) responses. However, it fails to induce secretory immunoglobulin (Ig) A (SIgA) in mucosal tissues and is poor in inducing Th1 and cell-mediated immunity. Alum stimulates interleukin 1 (IL-1) and the recruitment of myeloid cells, including neutrophils. We investigated whether neutrophil elastase regulates the adjuvanticity of alum, and whether a strategy targeting neutrophil elastase could improve responses to injected vaccines. Mice coadministered a pharmacological inhibitor of elastase, or lacking elastase, developed high-affinity serum IgG and IgA antibodies after immunization with alum-adsorbed protein vaccines, including the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2). These mice also developed broader antigen-specific CD4+ T cell responses, including high Th1 and T follicular helper (Tfh) responses. Interestingly, in the absence of elastase activity, mucosal SIgA responses were induced after systemic immunization with alum as adjuvant. Importantly, lack or suppression of elastase activity enhanced the magnitude of anti-SARS-CoV-2 spike subunit 1 (S1) antibodies, and these antibodies reacted with the same epitopes of spike 1 protein as sera from COVID-19 patients. Therefore, suppression of neutrophil elastase could represent an attractive strategy for improving the efficacy of alum-based injected vaccines for the induction of broad immunity, including mucosal immunity.

Prevention of nodules and enhancement of antibody response to genetically engineered recombinant vaccine against Human Chorionic Gonadotropin (hCG) for contraception.

OBJECTIVE: Human Chorionic Gonadotropin (hCG) plays a crucial role in embryo implantation and in maintenance of pregnancy. An immuno-contraceptive approach involves the use of a recombinant hCGß-LTB vaccine formulated with adjuvant Mycobacterium indicus pranii (MIP), to prevent pregnancy without disturbing ovulation, hormonal profiles, and menstrual cycles in women. The present work in mice was designed to address issues encountered in clinical trials conducted with hCGß-LTB vaccine, with focus on two primary concerns. Firstly, it aimed to determine the optimal vaccine dosage required to induce a high level of anti-hCG antibodies. Secondly, it aimed to assess the safety profile of the vaccine, specifically injection site reactions in the form of nodules, observed in some of the subjects. METHODS AND RESULTS: Studies undertaken indicate that a 2 µg dose of the protein version of the vaccine, administered in mice through the intramuscular route, can induce high anti-hCG titres. Furthermore, administering a booster dose enhances the antibody response. Our findings suggest that the concentration and frequency of administration of the adjuvant MIP can also be reduced without compromising vaccine efficacy. CONCLUSION: The issue of nodule formation at the injection site can be mitigated either by administering the vaccine along with MIP intramuscularly or injecting hCG vaccine and MIP at separate intradermal sites. Thus, protein vaccine administered at a 2µg dose via the intramuscular route addresses both efficacy and safety concerns.

The Phase I/II clinical trials initiated with the recombinant hCG vaccine in women revealed inadequate antibody titres in all subjects, alongside the development of nodules at the injection sites in some participants. Studies were undertaken in mice to propose potential strategies for mitigating injection site reactions and enhancing the antibody response. It was concluded that the optimum dose of the protein version of the vaccine to get high antibody titres, is 2 µg administered intramuscularly while upholding safety standards.

Antibiotic use differentially affects the risk of anti-drug antibody formation during anti-TNFα therapy in inflammatory bowel disease patients: a report from the epi-IIRN.

OBJECTIVE: Anti-drug antibodies (ADA) to anti-tumour necrosis factor (anti-TNF) therapy drive treatment loss of response. An association between intestinal microbial composition and response to anti-TNF therapy was noted. We therefore aimed to assess the implications of antibiotic treatments on ADA formation in patients with inflammatory bowel disease (IBD). DESIGN: We analysed data from the epi-IIRN (epidemiology group of the Israeli IBD research nucleus), a nationwide registry of all patients with IBD in Israel. We included all patients treated with anti-TNF who had available ADA levels. Survival analysis with drug use as time varying covariates were used to assess the association between antibiotic use and ADA development. Next, specific pathogen and germ-free C57BL mice were treated with respective antibiotics and challenged with infliximab. ADA were assessed after 14 days. RESULTS: Among 1946 eligible patients, with a median follow-up of 651 days from initiation of therapy, 363 had positive ADA. Cox proportional hazard model demonstrated an increased risk of ADA development in patients who used cephalosporins (HR=1.97, 95% CI 1.58 to 2.44), or penicillins with ß-lactamase inhibitors (penicillin-BLI, HR=1.4, 95% CI 1.13 to 1.74), whereas a reduced risk was noted in patients treated with macrolides (HR=0.38, 95% CI 0.16 to 0.86) or fluoroquinolones (HR=0.20, 95% CI 0.12 to 0.35). In mice exposed to infliximab, significantly increased ADA production was observed in cephalosporin as compared with macrolide pretreated mice. Germ-free mice produced no ADA. CONCLUSION: ADA production is associated with the microbial composition. The risk of ADA development during anti-TNF therapy can possibly be reduced by avoidance of cephalosporins and penicillin-BLIs, or by treatment with fluoroquinolones or macrolides.

Efficacy and safety of heterologous booster vaccination with Ad26.COV2.S after BNT162b2 mRNA COVID-19 vaccine in haemato-oncological patients with no antibody response.

Patients with haemato-oncological malignancies are one of the high-risk groups for a severe course in case of COVID-19 infections. Furthermore, vaccination results in significantly lower response rates in haematological malignancies and lower antibody levels in patients with solid cancer. We investigated efficacy and safety of a heterologous booster vaccination with Ad26.COV2.S DNA vector vaccine in haemato-oncological patients without antibody response after double-dose BNT162b2 messenger (m-)RNA COVID-19 vaccine. A total of 32 haemato-oncological non-responders to double-dose BNT162b2 received a heterologous booster vaccination with Ad26.COV2.S. Blood samples were assessed directly before the vaccination (T0) and four weeks after (T1). Safety assessment was performed using a standardised questionnaire. The overall response rate was 31%, with a mean (SD) antibody titre of 693·79 (1 096·99) binding activity units (BAU)/ml. Patients with chronic lymphocytic leukaemia or lymphoma showed a significantly lower response rate (P = 0·048). Adverse events were reported in 29·6% of patients, of which 7·1% were graded as severe, including grade III and IV events following the Common Terminology Criteria of Adverse Events (CTCAE). The heterologous booster vaccination with Ad26.COV2.S led to a serological response in nine out of 29 patients without response after double-dose BNT162b2. Furthermore, the vaccination was safe in our cohort, leading to mainly mild local and systemic reactions. Overall, this vaccination regimen should be further evaluated to increase the response rate in the highly vulnerable population of haemato-oncological patients.

BCL6 BTB-specific inhibitor reversely represses T-cell activation, Tfh cells differentiation, and germinal center reaction in vivo.

Inhibition of the BCL6 BTB domain results in killing Diffuse Large B-cell Lymphoma (DLBL) cells, reducing the T-cell dependent germinal center (GC) reaction in mice, and reversing GC hyperplasia in nonhuman primates. The available BCL6 BTB-specific inhibitors are poorly water soluble, thus, limiting their absorption in vivo and our understanding of therapeutic strategy targeting GC. We synthesized a prodrug (AP-4-287) from a potent BCL6 BTB inhibitor (FX1) with improved aqueous solubility and pharmacokinetics (PK) in mice. We also evaluated its in vivo biological activity on humoral immune responses using the sheep red blood cells (SRBC)-vaccination mouse model. AP-4-287 had a significant higher aqueous solubility and was readily converted to FX1 in vivo after intraperitoneally (i.p.) administration, but a shorter half-life in vivo. Importantly, AP-4-287 treatment led to a reversible effect on (1) the reduction in the frequency of splenic Ki67+ CD4+ T cells, Tfh cells, and GC B cells; (2) lower GC formation following vaccination; and (3) a decrease in the titers of antigen-specific IgG and IgM antibodies. Our study advances the preclinical development of drug targeting BCL6 BTB domain for the treatment of diseases that are associated with abnormal BCL6 elevation.

An analysis of antibody responses and clinical sequalae of the Sinopharm HB02 COVID19 vaccine in dialysis patients in the United Arab Emirates.

AIM: To establish the responses to the Sinopharm HB02 COVID-19 vaccination in the dialysis population, which are not well established. We examined the humoral responses to the Sinopharm COVID vaccine in haemodialysis patients. METHODS: Standard vaccinations (two doses at interval of ~21 days) were given to all consenting haemodialysis patients on dialysis (n = 1296). We measured the antibody responses at 14-21 days after the second vaccine to define the development of anti-spike antibodies >15 AU/ml after vaccination and observed the clinical effects of vaccination. RESULTS: Vaccination was very well tolerated with few side-effects. In those who consented to antibody measurements, (n = 446) baseline sampling showed 77 had positive antibodies, yet received full vaccination without any apparent adverse events. Positive anti-spike antibodies developed in 50% of the 270 baseline negative patients who had full sampling, compared with 78.1% in the general population. COVID infection continues to occur in both vaccinated and unvaccinated individuals, but in the whole group vaccination appears to have been associated with a reduction in the case fatality rate. CONCLUSION: The humoral immune responses to standard HB02 vaccination schedules are attenuated in a haemodialysis cohort, but likely the vaccine saves lives. We suggest that an enhanced HB02 vaccination course or antibody checking may be prudent to protect this vulnerable group of patients. We suggest a booster dose of this vaccine at 3 months should be given to all dialysis patients, on the grounds that it is well tolerated even in those with good antibody levels and there may be a survival advantage.

Erythropoietin Reduces Auto- and Alloantibodies by Inhibiting T Follicular Helper Cell Differentiation.

BACKGROUND: Although high-affinity IgG auto- and alloantibodies are important drivers of kidney inflammation that can result in ESKD, therapeutic approaches that effectively reduce such pathogenic antibodies remain elusive. Erythropoietin (EPO) has immunomodulatory functions, but its effects on antibody production are unknown. METHODS: We assessed the effect and underlying mechanisms of EPO/EPO receptor (EPOR) signaling on primary and secondary, T cell-dependent and T-independent antibody formation using in vitro culture systems, murine models of organ transplantation and lupus nephritis, and mice conditionally deficient for the EPOR expressed on T cells or B cells. RESULTS: In wild-type mice, recombinant EPO inhibited primary, T cell-dependent humoral immunity to model antigens and strong, polyclonal stimuli, but did not alter T-independent humoral immune responses. EPO also significantly impaired secondary humoral immunity in a potent allogeneic organ transplant model system. The effects required T cell, but not B cell, expression of the EPOR and resulted in diminished frequencies of germinal center (GC) B cells and T follicular helper cells (TFH). In vitro and in vivo experiments showed that EPO directly prevented TFH differentiation and function via a STAT5-dependent mechanism that reduces CD4+ T cell expression of Bcl6. In lupus models, EPO reduced TFH, GC B cells, and autoantibody production, and abrogated autoimmune glomerulonephritis, demonstrating clinical relevance. In vitro studies verified that EPO prevents differentiation of human TFH cells. CONCLUSIONS: Our findings newly demonstrate that EPO inhibits TFH-dependent antibody formation, an observation with potential implications for treating antibody-mediated diseases, including those of the kidney.

Oral insulin immunotherapy in children at risk for type 1 diabetes in a randomised controlled trial.

AIMS/HYPOTHESIS: Oral administration of antigen can induce immunological tolerance. Insulin is a key autoantigen in childhood type 1 diabetes. Here, oral insulin was given as antigen-specific immunotherapy before the onset of autoimmunity in children from age 6 months to assess its safety and immune response actions on immunity and the gut microbiome. METHODS: A phase I/II randomised controlled trial was performed in a single clinical study centre in Germany. Participants were 44 islet autoantibody-negative children aged 6 months to 2.99 years who had a first-degree relative with type 1 diabetes and a susceptible HLA DR4-DQ8-containing genotype. Children were randomised 1:1 to daily oral insulin (7.5 mg with dose escalation to 67.5 mg) or placebo for 12 months using a web-based computer system. The primary outcome was immune efficacy pre-specified as induction of antibody or T cell responses to insulin and measured in a central treatment-blinded laboratory. RESULTS: Randomisation was performed in 44 children. One child in the placebo group was withdrawn after the first study visit and data from 22 insulin-treated and 21 placebo-treated children were analysed. Oral insulin was well tolerated with no changes in metabolic variables. Immune responses to insulin were observed in children who received both insulin (54.5%) and placebo (66.7%), and the trial did not demonstrate an effect on its primary outcome (p = 0.54). In exploratory analyses, there was preliminary evidence that the immune response and gut microbiome were modified by the INS genotype Among children with the type 1 diabetes-susceptible INS genotype (n = 22), antibody responses to insulin were more frequent in insulin-treated (72.7%) as compared with placebo-treated children (18.2%; p = 0.03). T cell responses to insulin were modified by treatment-independent inflammatory episodes. CONCLUSIONS/INTERPRETATION: The study demonstrated that oral insulin immunotherapy in young genetically at-risk children was safe, but was not associated with an immune response as predefined in the trial primary outcome. Exploratory analyses suggested that antibody responses to oral insulin may occur in children with a susceptible INS genotype, and that inflammatory episodes may promote the activation of insulin-responsive T cells. TRIAL REGISTRATION: Clinicaltrials.gov NCT02547519 FUNDING: The main funding source was the German Center for Diabetes Research (DZD e.V.).

Analysis of antibody responses after COVID-19 vaccination in liver transplant recipients and those with chronic liver diseases.

BACKGROUND & AIMS: Liver transplant (LT) recipients or other immunocompromised patients were not included in the registration trials studying the efficacy of vaccines against SARS-CoV-2. Although the clinical efficacy of COVID-19 vaccines in immunocompromised patients is unknown, many societies have recommended vaccination of this highly vulnerable patient population. METHODS: In this prospective study, we determined antibody responses to spike protein, 4 weeks after the 2nd dose of mRNA vaccines or after the single dose of Johnson & Johnson vaccine, in LT recipients and those with chronic liver disease (CLD) with and without cirrhosis. RESULTS: Of the 233 patients enrolled so far, 62 were LT recipients, 79 had cirrhosis (10 decompensated) and 92 had CLD without cirrhosis. Antibody titers were defined as undetectable (<0.40 U/ml), suboptimal (0.40-250 U/ml) and adequate (>250 U/ml). Of the 62 patients who had LT, antibody levels were undetectable in 11 patients and suboptimal (median titer 17.6, range 0.47-212 U/ml) in 27 patients. Among 79 patients with cirrhosis, 3 had undetectable antibody levels and 15 had suboptimal (median titer 41.3, range 0.49-221 U/L) antibody responses. Of the 92 patients without cirrhosis, 4 had undetectable antibody levels and 19 had suboptimal (median titer 95.5, range 4.9-234 U/L) antibody responses. Liver transplantation, use of 2 or more immunosuppression medications and vaccination with a single dose of the Johnson & Johnson vaccine were associated with poor immune response on multivariable analysis. No patient had any serious adverse events. CONCLUSIONS: Poor antibody responses after SARS-CoV-2 vaccination were seen in 61% of LT recipients and 24% of those with CLD. LAY SUMMARY: The clinical efficacy of COVID-19 vaccines in immunocompromised patients is unknown. We performed a prospective study to evaluate immune responses to COVID-19 vaccines (Moderna, Pfizer or Johnson & Johnson) in 62 liver transplant recipients, 79 patients with cirrhosis and 92 with chronic liver diseases without cirrhosis. We found that 17.8% of liver transplant recipients, 3.8% of those with cirrhosis and 4.3% of those with chronic liver diseases without cirrhosis had undetectable antibody levels. In total, 61.3% of liver transplant recipients and 24% of those with chronic liver diseases (with or without cirrhosis) had poor antibody responses (undetectable or suboptimal). Liver transplantation, use of immunosuppressive medications and vaccination with a single dose of Johnson & Johnson vaccine were associated with poor antibody responses when adjusted for other factors.

Serological SARS-CoV-2 antibody response, potential predictive markers and safety of BNT162b2 mRNA COVID-19 vaccine in haematological and oncological patients.

Haemato-oncological patients are at risk in case of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Currently, vaccination is the best-evaluated preventive strategy. In the present study, we aimed to assess serological response, predictive markers, and safety of BNT162b2 in haemato-oncological patients. A total of 259 haemato-oncological patients were vaccinated with two 30 µg doses of BNT162b2 administered 21 days apart. Serological response was assessed by ELECSYS® Anti-SARS-CoV-2-S immunoassay before vaccination, and at 3 and 7 weeks after the first dose (T1, T2). Safety assessment was performed. At T2 spike protein receptor binding domain (S/RBD) antibodies were detected in 71·4% of haematological and in 94·5% of oncological patients (P < 0·001). Haematological patients receiving systemic treatment had a 14·2-fold increased risk of non-responding (95% confidence interval 3·2-63·3, P = 0·001). Subgroups of patients with lymphoma or chronic lymphocytic leukaemia were at highest risk of serological non-response. Low immunoglobulin G (IgG) level, lymphocyte- and natural killer (NK)-cell counts were significantly associated with poor serological response (P < 0·05). Vaccination was well tolerated with only 2·7% of patients reporting severe side-effects. Patients with side-effects developed a higher S/RBD-antibody titre compared to patients without side-effects (P = 0·038). Haematological patients under treatment were at highest risk of serological non-response. Low lymphocytes, NK cells and IgG levels were found to be associated with serological non-response. Serological response in oncological patients was encouraging. The use of BNT162b2 is safe in haemato-oncological patients.

High-throughput compound screen reveals mTOR inhibitors as potential therapeutics to reduce (auto)antibody production by human plasma cells.

Antibody production by the B cell compartment is a crucial part of the adaptive immune response. Dysregulated antibody production in the form of autoantibodies can cause autoimmune disease. To date, B-cell depletion with anti-CD20 antibodies is commonly applied in autoimmunity, but pre-existing plasma cells are not eliminated in this way. Alternative ways of more selective inhibition of antibody production would add to the treatment of these autoimmune diseases. To explore novel therapeutic targets in signaling pathways essential for plasmablast formation and/or immunoglobulin production, we performed a compound screen of almost 200 protein kinase inhibitors in a robust B-cell differentiation culture system. This study yielded 35 small cell-permeable compounds with a reproducible inhibitory effect on B-cell activation and plasmablast formation, among which was the clinically applied mammalian target of rapamycin (mTOR) inhibitor rapamycin. Two additional compounds targeting the phosphoinositide 3-kinase-AKT-mTOR pathway (BKM120 and WYE-354) did not affect proliferation and plasmablast formation, but specifically reduced the immunoglobulin production. With this compound screen we successfully applied a method to investigate therapeutic targets for B-cell differentiation and identified compounds in the phosphoinositide 3-kinase-AKT-mTOR pathway that could specifically inhibit immunoglobulin production only. These drugs may well be explored to be of value in current B-cell-depleting treatment regimens in autoimmune disorders.

Toward a universal influenza virus vaccine: Some cytokines may fulfill the request.

The influenza virus annually causes widespread damages to the health and economy of the global community. Vaccination is currently the most crucial strategy in reducing the number of patients. Genetic variations, the high diversity of pandemic viruses, and zoonoses make it challenging to select suitable strains for annual vaccine production. If new pandemic viruses emerge, it will take a long time to produce a vaccine according to the new strains. In the present study, intending to develop a universal influenza vaccine, new bicistronic DNA vaccines were developed that expressed NP or NPm antigen with one of modified IL-18/ IL-17A/ IL-22 cytokine adjuvants. NPm is a mutant form of the antigen that has the ability for cytoplasmic accumulation. In order to investigate and differentiate the role of each of the components of Th1, Th2, Th17, and Treg cellular immune systems in the performance of vaccines, Treg competent and Treg suppressed mouse groups were used. Mice were vaccinated with Foxp3-FC immunogen to produce Treg suppressed mouse groups. The potential of the vaccines to stimulate the immune system was assessed by IFN-γ/IL-17A Dual FluoroSpot. The vaccine's ability to induce humoral immune response was determined by measuring IgG1, IgG2a, and IgA-specific antibodies against the antigen. Kinetics of Th1, Th2, and Th17 cellular immune responses after vaccination, were assessed by evaluating the expression changes of IL-17A, IFN-γ, IL-18, IL-22, IL-4, and IL-2 cytokines by semi-quantitative real-time RT-PCR. To assess the vaccines' ability to induce heterosubtypic immunity, challenge tests with homologous and heterologous viruses were performed and then the virus titer was measured in the lungs of animals. Evaluation of the data obtained from this study showed that the DNA-vaccines coding NPm have more ability to induces a potent cross-cellular immune response and protective immunity than DNA-vaccines coding NP. Although the use of IL-18/ IL-17A/ IL-22 genetic adjuvants enhanced immune responses and protective immunity, Administration of NPm in combination with modified IL-18 (Igk-mIL18-IgFC) induced the most effective immunity in Treg competent mice group.

Antibody Development in Patients Treated Long-Term With OnabotulinumtoxinA for Benign Essential Blepharospasm and Hemifacial Spasm.

BACKGROUND: Report the development of onabotulinumtoxinA neutralizing antibodies in patients treated consecutively for 20 years or longer for benign essential blepharospasm (BEB), hemifacial spasm (HFS), and Meige Syndrome. METHODS: Prospective, randomized, cross-sectional study of 12 randomly selected patients from a single clinical practice that have been treated consecutively for 20 or more years with onabotulinumtoxinA for BEB, HFS, or Meige Syndrome. Serum samples were collected from each subject and analyzed for neutralizing antibody formation using the Mouse Protection Assay. RESULTS: None of the tested patients (0%) displayed neutralizing antibodies to onabotulinumtoxinA. The mean duration of treatment was 27.5 years (range 22.1-34.1, SD 3.1, 95% confidence interval 25.45-29.50). Nine of the patients had a diagnosis of BEB, 2 HFS, and one Meige. Eleven of the 12 patients were women. There was no statistically significant difference in treatment dosage or interval over the course of treatment. CONCLUSIONS: The data support previous studies showing low incidence of antibody formation for botulinum A toxins with this subset of long-term treated patients. The results also provide further evidence for studies that have suggested increased onabotulinumtoxinA treatment volumes and/or decreased intervals between treatments are not due to neutralizing antibody formation and secondary non-response, but rather study designs that do not consider the titration phase of initial treatments. This study is specific to long-term treated patients, and the results cannot be generalized to patients naive to treatment.

Application of the Antibody-Inducing Activity of Glycosphingolipids to Human Diseases.

Glycosphingolipids (GSLs) are composed of a mono-, di-, or oligosaccharide and a ceramide and function as constituents of cell membranes. Various molecular species of GSLs have been identified in mammalian cells due to differences in the structures of oligosaccharides. The oligosaccharide structure can vary depending on cell lineage, differentiation stage, and pathology; this property can be used as a cell identification marker. Furthermore, GSLs are involved in various aspects of the immune response, such as cytokine production, immune signaling, migration of immune cells, and antibody production. GSLs containing certain structures exhibit strong immunogenicity in immunized animals and promote the production of anti-GSL antibodies. By exploiting this property, it is possible to generate antibodies that recognize the fine oligosaccharide structure of specific GSLs or glycoproteins. In our study using artificially synthesized GSLs (artGSLs), we found that several structural features are correlated with the antibody-inducing activity of GSLs. Based on these findings, we designed artGSLs that efficiently induce the production of antibodies accompanied by class switching and developed several antibodies that recognize not only certain glycan structures of GSLs but also those of glycoproteins. This review comprehensively introduces the immune activities of GSLs and their application as pharmaceuticals.

Inhibition of Bruton Tyrosine Kinase Reduces Neuroimmune Cascade and Promotes Recovery after Spinal Cord Injury.

Microglia/astrocyte and B cell neuroimmune responses are major contributors to the neurological deficits after traumatic spinal cord injury (SCI). Bruton tyrosine kinase (BTK) activation mechanistically links these neuroimmune mechanisms. Our objective is to use Ibrutinib, an FDA-approved BTK inhibitor, to inhibit the neuroimmune cascade thereby improving locomotor recovery after SCI. Rat models of contusive SCI, Western blot, immunofluorescence staining imaging, flow cytometry analysis, histological staining, and behavioral assessment were used to evaluate BTK activity, neuroimmune cascades, and functional outcomes. Both BTK expression and phosphorylation were increased at the lesion site at 2, 7, 14, and 28 days after SCI. Ibrutinib treatment (6 mg/kg/day, IP, starting 3 h post-injury for 7 or 14 days) reduced BTK activation and total BTK levels, attenuated the injury-induced elevations in Iba1, GFAP, CD138, and IgG at 7 or 14 days post-injury without reduction in CD45RA B cells, improved locomotor function (BBB scores), and resulted in a significant reduction in lesion volume and significant improvement in tissue-sparing 11 weeks post-injury. These results indicate that Ibrutinib exhibits neuroprotective effects by blocking excessive neuroimmune responses through BTK-mediated microglia/astroglial activation and B cell/antibody response in rat models of SCI. These data identify BTK as a potential therapeutic target for SCI.

Design, Synthesis, and Biological Evaluation of Desmuramyl Dipeptides Modified by Adamantyl-1,2,3-triazole.

Muramyl dipeptide (MDP) is the smallest peptidoglycan fragment able to trigger the immune response. Structural modification of MDP can lead to the preparation of analogs with improved immunostimulant properties, including desmuramyl peptides (DMPs). The aim of this work was to prepare the desmuramyl peptide (L-Ala-D-Glu)-containing adamantyl-triazole moiety and its mannosylated derivative in order to study their immunomodulatory activities in vivo. The adjuvant activity of the prepared compounds was evaluated in a murine model using ovalbumin as an antigen, and compared to the reference adjuvant ManAdDMP. The results showed that the introduction of the lipophilic adamantyl-triazole moiety at the C-terminus of L-Ala-D-Glu contributes to the immunostimulant activity of DMP, and that mannosylation of DMP modified with adamantyl-triazole causes the amplification of its immunostimulant activity.

Hepatitis B core-specific memory B cell responses associate with clinical parameters in patients with chronic HBV.

BACKGROUND & AIMS: Little is known about the frequency, phenotype and function of HBV-specific B cells during chronic infection. Here we study HBcAg and HBsAg-specific B cells in different clinical phases of a chronic HBV infection. METHODS: We included 118 treatment naïve and 34 nucleos(t)ide analogue-treated patients with chronic HBV and 23 healthy HBsAg-vaccinated controls. Global and HBV-specific B lymphocytes were examined by FACS using fluorescently labeled HBsAg and HBcAg as baits. Functional HBV-specific B cell responses were quantified in B cell ELISPOT assays. Anti-HBs and anti-HBc antibodies were measured in serum and in ELISPOT supernatant by ELISA. RESULTS: Higher HBcAg-directed B cell responses were found in HBV clinical phases with elevated vs. low serum alanine aminotransferase (ALT) levels, irrespective of the HBeAg-status. In contrast, HBsAg-directed responses were lower and did not significantly fluctuate. In individual patients a mean 17.8-fold more circulating B cells target HBcAg than HBsAg baits. These HBcAg-specific B cells present a classical memory B cell profile and have slightly higher CD69 expression levels compared to global memory B cells. Viral suppression and ALT normalization upon treatment led to a numeric and functional reduction of HBcAg-specific B cell responses, accompanied by progressive decreases in serum anti-HBc antibodies. CONCLUSION: HBcAg-specific memory B cells present a classical memory B cell phenotype, vary in number and function throughout HBV's natural history and are significantly reduced during antiviral treatment. LAY SUMMARY: In recent years, studies examining the role of B cells during chronic hepatitis B virus infection have regained interest. We show that circulating B cells more often target the hepatitis B core antigen than the hepatitis surface antigen. Moreover, these hepatitis B core-specific B cells associate with the natural history of chronic HBV, and their responses decline during effective antiviral treatment.