Immunization Protocol Research Articles

Linking antibody against apolipoprotein A-1 to metabolic dysfunction-associated steatohepatitis in mice

Abstract Background Metabolic dysfunction-associated fatty liver disease (MASLD) is a common liver condition associated with increased cardiovascular disease (CVD) risk. Cytokeratin 18 (CK-18) is indicative of liver injury and used as a surrogate biomarker covering MASLD to cirrhosis phenotypes. Autoantibodies against apolipoprotein A-1 (AAA-1) are known CVD risk factors inducing MASLD in vitro, but their role in modulating steatohepatitis and fibrosis in vivo is still elusive. We investigated AAA-1's contribution to systemic low-grade inflammation, liver steatosis, and fibrosis using a MASLD mouse model and a validated passive immunization protocol (PIP). Methods 10 weeks-old male C57BL/6J mice were fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) and immunized with AAA-1 (200ug) or control antibodies for ten days. At sacrifice, plasma samples were collected, and CK-18 levels, and proinflammatory cytokines were measured using the Mesoscale Discovery platform. Hematoxylin and Eosin and Sirius Red Fast Green staining were used to reveal liver steatosis and fibrosis, respectively. RNA were extracted from mouse liver samples and mRNA were then analyzed using a commercial fibrosis-specific genes panel (nCounter Human Fibrosis V2 Panel) and the nCounter Analysis System. Results Compared to control IgG recipients, CDAHFD mice injected with AAA-1 exhibited significantly elevated plasma levels of CK-18 (5.3 vs 2.1, p=0.031), IL-6 (13 vs 6.9, p=0.035), IL-10 (27.3 vs 9.8, p=0.007) and TNF-α (32.1 vs 24.2, p=0.032), and liver steatosis (93.4% vs 73.8%, p=0.007). Nanostring technology experiments revealed upregulation of several pro-fibrotic m-RNAs in liver tissue from AAA-1 immunized mice compared to the IgG immunized control group. These included Serum Amyloid A (Fold Change (FC) AAA-1 vs IgG : 2.5, p=0.02) , G-protein coupled receptors 65 (FC: 2.7, p=0.01), Periostin (FC: 2.6, p=0.001), Phospholipid transfer protein (FC: 2.2, p=0.0004), Vascular Cell Adhesion Molecule 1 (FC: 2.5, p=0.02) and Angiopoietin-like 4 (FC: 2.8, p=0.01). Histologically, the amount of liver fibrosis remained unaffected, probably due to the short time of the study. Conclusions Short AAA-1 PIP induced enhanced liver steatosis and inflammation accompanied by an elevation of the expression of several pro-fibrotic genes in CDAHFD mice, suggesting that AAA-1 may contribute to the transition from MASLD to MASH. Knowing whether increased exposure time to AAA-1 could lead to end stage disease (including cirrhosis and HCC), and if this could apply to humans as well warrant further investigations.

21st century Latin American synthetic peptides for their application in antivenom production

Envenomation caused by snakes, scorpions, and spiders represents a serious public health problem in Latin America. The antivenoms used for its treatment are produced by immunizing horses repeatedly with sublethal doses of animal venoms along with the adjuvant. However, venom availability is a bottleneck. Furthermore, toxin-neutralizing antibodies are only a few of the total produced with this classical method. Therefore, high doses of antivenom are required to achieve the neutralization power, which usually causes adverse reactions in the patient. With the aim of obtaining a higher proportion of toxin-neutralizing antibodies while reducing the dependency on venom availability, alternative immunization protocols have been explored using synthetic peptides with epitopes from clinically relevant toxins. The process to design an immunogenic peptide entitles: (a) choice of the medical relevant toxins in the venom; (b) identification of the epitopes in the selected toxins; (c) improvement of peptide immunogenicity; (d) immunogen synthesis; and e) in vitro and in vivo evaluation. The present article aims to review the advances in the design of immunogenic synthetic peptides for their application in antivenom production in Latin America during the 21st century. Epitopes have been identified from many clinically important toxins in Latin American snakes (snake venom metalloproteinases, snake venom serine proteases, crotamine, phospholipases A2, and three-finger toxins), scorpions (beta-mammal/insect toxin Ts1, alpha-mammal toxin Ts2, alpha-mammal toxin Ts3, toxin Ts4, and beta-mammal Tt1g neurotoxin), and spiders (dermonecrotic toxin and delta-ctenitoxin-Pn2a). Nevertheless, their application is still experimental, even though they are ideal for large-scale and low-cost antivenom production, factors that are necessary to meet national and regional demands.

Calf immunization protocols with low-virulence isolates of Anaplasma marginale: Analysis of post-inoculation effects and protection against natural challenge

Bovine anaplasmosis is endemic and is of fundamental importance worldwide. Therefore, measures for controlling and preventing clinical diseases are warranted to ensure the reduction of associated economic losses. The objective of the present study was to assess the post-inoculation effects and protection conferred by three different protocols of inoculation of low-virulence live strains of Anaplasma marginale (UFMG1 and UFMG3) in field-challenged cattle. Sixty-eight Holstein calves with an average age of 17 days were randomly divided into four groups. The groups received two subcutaneous administrations spaced 40 days apart, at a dosage of 2 × 106 infected erythrocytes of the following A. marginale strains: G1 (UFMG1 + UFMG1); G2 (UFMG3 + UFMG3); G3 (UFMG1 + UFMG3); and G4 (control). Every two days, the animals were evaluated for rectal temperature, Packed Cell Volume (PCV), and blood smears. Blood samples were collected prior to inoculation, before the field challenge, and after the challenge period, nPCR and IFAT techniques were performed. There were no significant differences in rickettsemia levels, reduction in PCV, or antibody detection among the different inoculation strategies. Forty days after the second inoculation, 90 %, 84.6 %, and 90.9 % of the animals in G1, G2, and G3, respectively, tested positive using nPCR. After inoculation, the group G2, which received the UFMG3 inoculum, had a higher frequency of treatment (odds ratio of 6.7; 1.198-38.018 CI; p = 0.03), while groups G1 and G3 demonstrated similar treatment frequencies compared to the control. During the natural challenge phase, 13.3 % of animals in group G1 required treatment (odds ratio of 0.108; 0.018-0.635 CI; p = 0.014) compared to 58.8 % of the control group. Considering the results collectively, the protocol using the UFMG1 strain (G1) stands out for its potential to be safe and induce some degree of immunization against A. marginale, reducing the incidence of clinical disease and the need for treatment during natural challenge.

Regulatory cell therapy for kidney transplantation and autoimmune kidney diseases.

Regulatory cell therapies, including regulatory T cells and mesenchymal stromal cells, have shown promise in early clinical trials for reducing immunosuppression burden in transplantation. While regulatory cell therapies may also offer potential for treating autoimmune kidney diseases, data remains sparse, limited mainly to preclinical studies. This review synthesises current literature on the application of regulatory cell therapies in these fields, highlighting the safety and efficacy shown in existing clinical trials. We discuss the need for further clinical validation, optimisation of clinical and immune monitoring protocols, and the challenges of manufacturing and quality control under Good Manufacturing Practice conditions, particularly for investigator-led trials. Additionally, we explore the potential for expanding clinical indications and the unique challenges posed in paediatric applications. Future directions include scaling up production, refining protocols to ensure consistent quality across manufacturing sites, and extending applications to other immune-mediated diseases.

Oral Live-Carrier Vaccine of Recombinant Lactococcus lactis Inducing Prophylactic Protective Immunity Against Helicobacter pylori Infection.

Helicobacter pylori infects the gastric mucosa and induces chronic gastritis, peptic ulcers, and gastric cancer. Research has demonstrated that vaccination can induce a protective immune response and prevent H. pylori infection. Oral administration of the Lactococcus lactis live-carrier vaccine is safe and easily complied with by the public. In this study, two recombinant L. lactis strains were constructed that expressed antigens of H. pylori urease subunit alpha (UreA) and UreA fused with Escherichia coli heat-labile toxin B subunit (LTB-UreA), named LL-UreA and LL-LTB-UreA, respectively. The expression of antigen proteins was confirmed by Western blotting analysis. Survival assessment indicated that the engineered L. lactis could colonize in the digestive tract of BALB/c mice up to 10 days after the last oral administration with our immunization protocol. The ability to induce immune response and immune protective efficacy of the L. lactis were confirmed. These results indicated that oral administration with LL-UreA or LL-LTB-UreA could induce UreA-specific mucosal secretory IgA (sIgA) and cellular immune response, significantly increasing the cytokines levels of interferon-gamma (IFN-γ), interleukin (IL)-17A, and IL-10, together with the proportion of CD4+IFN-γ+ T cells and CD4+IL17A+ T cells. More importantly, oral administration of LL-UreA and LL-LTB-UreA brought about effective protection in mice to prevent H. pylori infection, especially LL-UreA, resulting in 70% of mice showing no H. pylori colonization and the remaining 30% showing only low levels of colonization. These findings underscore the potential of using orally administered engineered L. lactis vaccines to prevent H. pylori infection.

Design, development and preclinical assessment of MENAVip-ICP, a new snake antivenom with potential coverage of species in the Middle East and North Africa regions

Snakebite in the Middle East and North Africa (MENA) is a public health problem whose magnitude is not fully known. Several antivenoms are available in these regions, but these formulations are designed for restricted geographical settings. Many countries do not have local production of antivenoms and must access products whose clinical performance has not been demonstrated. We hypothesize that it is possible to unify the treatment for viperid snakebites of MENA in a single antivenom formulation. Hereby we describe the design, development and preclinical evaluation of an antivenom of broad geographical coverage for this region (MENAVip-ICP). We produced this antivenom from the plasma of horses immunized with eight medically important venoms of viperid snake species from MENA. For this, we used a strategy based on two stages: first, immunization of horses with North African (NA) venoms, followed by a second immunization stage, on the same horses, with MENA venoms. We purified antivenoms from both stages: the Anti-NA and the final product Anti-MENA (MENAVip-ICP). Anti-NA was considered as intermediate formulation and was purified with the intention to study the progression of the immunoglobulin immune response of the horses. Antivenoms from both stages neutralized lethal, hemorrhagic, and procoagulant activities of homologous venoms. Compared to Anti-NA, MENAVip-ICP improved the neutralization profile of intravenous lethality and in vitro procoagulant activities of venoms. A notable finding was the difference in the neutralization of lethality when MENAVip-ICP was assessed intraperitoneally versus intravenously in the murine model. Intraperitoneally, MENAVip-ICP appears more effective in neutralizing the lethality of all venoms. Furthermore, MENAVip-ICP neutralized the lethal activity of venoms of species from other regions of MENA, Central/East Asia, and Sub-Saharan Africa that were not included in the immunization protocol. Our results showed that MENAVip-ICP neutralizes the main toxic activities induced by viperid MENA venoms at the preclinical level. Consequently, it is a promising product that could be clinically assessed for the treatment of snakebite envenomings in this region.

Tau-Targeted Immunotherapy for Alzheimer's Disease: Insight into Clinical Trials

The use of immunotherapy as a therapeutic approach to Alzheimer's Disease (AD) is gaining rapid interest, with the primary goal of targeting abnormalities that impact neuronal viability through specific antibodies. Currently, clinical strategies focus intensively on targeting the two main pathologies associated with AD, beta-amyloid (Ab) and tau. This review examines ongoing research in the realm of tau immunotherapy, including clinical trials that demonstrate promising potential for halting AD progression. Several trials are underway, focusing on improving tau-targeted immunotherapy tools based on passive and active immunization protocols. Tau-targeted therapies have proven relevant and demonstrated safety and efficacy in both animal models and human clinical trials. Some studies have demonstrated a reduction in tau protein aggregation in animal models, highlighting a potential mechanism by which these antibodies inhibit the spread of tau protein in the extracellular space. Recent discoveries have highlighted the potential role of tau-targeting therapy with antibodies and have revealed significant promise in treating pathological tau in AD.

Concanavalin-A-Induced Acute Liver Injury in Mice.

Acute liver injury is a life-threatening disease. Although immune responses are involved in the development and exacerbation of acute liver injury, the cellular and molecular mechanisms are not fully understood. Intravenous administration of the plant lectin concanavalin A (ConA) is widely used as a model of acute liver injury. ConA triggers T cell activation and cytokine production by crosslinking glycoproteins, including the T cell receptor, leading to the infiltration of myeloid cells into the liver and the subsequent amplification of inflammation in the liver. Thus, the pathogenesis of ConA-induced acute liver injury is considered a model of immune-mediated acute liver injury or autoimmune hepatitis in humans. However, the severity of the liver injury and the analyses of immune cells and non-hematopoietic cells in the liver following ConA injection are significantly influenced by the experimental conditions. This article outlines protocols for ConA-induced acute liver injury in mice and evaluation methods for liver injury, immune cells, and non-hematopoietic cells in the liver. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Induction of acute liver injury by ConA injection Basic Protocol 2: Evaluation of inflammatory cytokines in mouse plasma Basic Protocol 3: Preparation of liver sections and histological analysis of liver injury Basic Protocol 4: Preparation of liver immune cells Basic Protocol 5: Preparation of hepatocytes, endothelial cells, and hepatic stellate cells Basic Protocol 6: Flow cytometry of immune and non-hematopoietic liver cells Basic Protocol 7: Flow cytometric sorting of endothelial cells and hepatic stellate cells Basic Protocol 8: Quantitative reverse transcription polymerase chain reaction.

Efficacy and Prolonged Safety of Haemophilus influenzae Type b Conjugate Vaccines.

The purpose of this study was to find data proving the influence of the Haemophilus influenzae type b (Hib) conjugate vaccination on the frequency of invasive Hib illness. A systematic literature search was conducted on the PubMed database to identify peerreviewed publications pertaining to the epidemiology of Haemophilus influenzae meningitis, both before and after the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines. The search query employed a combination of relevant keywords, including "invasive," "Haemophilus," "influenzae," "meningitis," and specific serotype b (Hib). Additionally, terms related to epidemiology, burden, risk factors, impact, Hib vaccine, Hib conjugate vaccine, combination vaccine, vaccine production, efficacy, immunisation coverage, surveillance, review, clinical aspects, outcomes, and various age groups (adults and children) were incorporated. The search encompassed articles published till now. Subsequently, relevant research papers concerning Haemophilus influenzae meningitis were subjected to a comprehensive review and analysis. The Hib conjugate vaccination has shown to be extremely effective when administered to the entire population. However, changes to the immunisation protocol appear to be required in order to effectively manage invasive Hib illness.

Comparison of Post-Vaccination Cellular Immune Response in Patients with Common Variable Immune Deficiency.

The problem of identifying vaccine-specific T-cell responses is still a matter of debate. Currently, there are no universal, clearly defined, agreed upon criteria for assessing the effectiveness of vaccinations and their immunogenicity for the cellular component of immunity, even for healthy people. But for patients with inborn errors of immunity (IEI), especially those with antibody deficiencies, evaluating cellular immunity holds significant importance. To examine the effect of one and two doses of inactivated adjuvanted subunit influenza vaccines on the expression of endosomal Toll-like receptors (TLRs) on the immune cells and the primary lymphocyte subpopulations in patients with common variable immunodeficiency (CVID). During 2018-2019, six CVID patients received one dose of a quadrivalent adjuvanted influenza vaccine; in 2019-2020, nine patients were vaccinated with two doses of a trivalent inactivated influenza vaccine. The proportion of key lymphocyte subpopulations and expression levels of TLRs were analyzed using flow cytometry with monoclonal antibodies. No statistically significant alterations in the absolute values of the main lymphocyte subpopulations were observed in CVID patients before or after vaccination with the different immunization protocols. However, after vaccination, a higher expression of TLR3 and TLR9 in granulocytes, monocytes, and lymphocytes was found in those patients who received two vaccine doses rather than one single dose. This study marks the first instance of using a simultaneous two-dose vaccination, which is associated with an elevated level of TLR expression in the immune cells. Administration of the adjuvanted vaccines in CVID patients appears promising. Further research into their impact on innate immunity and the development of more effective vaccination regimens is warranted.

The effect of vaccination of gilts with a pre-farrow RNA particle vaccine following pre-breeding natural planned exposure on piglet growth and viral shedding

The objective of this study was to compare rotavirus shedding and performance of piglets from gilts immunized using natural planned exposure (NPE) or an RNA particle vaccine (RPV) prior to farrowing following initial NPE pre-breeding. A final total of 117 farrowed gilts and their piglets were enrolled into 4 groups. All gilts received two administrations of NPE prior to breeding. Gilts in group 1 were later given three NPE administrations at 5, 4, and 3 weeks prior to farrowing (WPF). Group 2 was dosed with an RNA particle vaccine (RPV) at 5 and 3 WPF and group 3 at 1 WPF only. Group 4 (control group) did not receive any NPE or RPV. Fecal samples from gilts and fecal swabs from their piglets were tested for rotavirus A (RVA), rotavirus B (RVB), and rotavirus C (RVC) by qRT-PCR. The 117 gilt samples were tested individually at 5 sampling points from pre-breeding to entry into the farrowing rooms. Piglet samples were pooled by litter (3 piglets sampled per litter) and tested at 3, 7, 14, and 21 days of age. The clinical and production impact of the treatments were assessed by comparing average adjusted weaning weights, the percentage of piglets weighing in the bottom 10% of study piglets at weaning, the percentage of piglets placed in the nursery, and the percentage of litters with the presence of diarrhea. No statistically significant differences were identified but there appeared to be several interesting numerical trends that are both biologically plausible and consistent among treatment groups. The control group, which received no pre-farrow immunization, had the highest percentage of litters with diarrhea at all time points and overall in the farrowing house. A numerical trend was also observed on average cycle threshold (Ct) values for RVC in piglets. Interestingly, the control group had the lowest numerical average Ct value at 7, 14, and 21 days of age. Ct values for RVA were consistently lower than for RVC in the stock solution and natural planned exposure gruel. This likely correlated to a lower level of RVC exposure in all gilts pre-breeding and group 1 gilts pre-farrow. This may have an inverse correlation to the higher levels of shedding of RVC in piglets. The lack of statistical significance between treatment groups with regard to diarrhea and weights in the piglets may be attributed to sample size, lack of sufficient natural rotavirus challenge, pre-breeding NPE in all gilts, or a variety of other reasons. Replication of this study with a larger sample size, using a challenge model, or relocated to a farm with increased natural rotavirus clinical challenges may yield different results. If beneficial under different conditions, the RPV would eliminate many of the risks associated with NPE administration, including continuous introduction of live virus on-farm, potential spread of other pathogens, difficulty of isolating on-farm strains, and labor and cost of producing NPE material. Limitations of the original research include the use of quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) to measure the levels of RVA and RVC in the stock solution and gruel and to monitor RV shedding, rather than techniques with the ability to differentiate live and non-viable virus. Additionally, these studies were performed on an all-gilt breeding farm. It may be more challenging to appreciate differences in treatment groups on a multiparous sow farm due to the higher level of immunity correlated to increasing parity. These immunization protocols were designed to be applicable in a field setting for routine rotavirus immunization, though their feasibility must be carefully considered before implementation on each individual farm.

Adjuvant ArtinM favored the host immunity against Cryptococcus gattii infection in C57BL/6 mice.

Aim: Cryptococcus gattii causes a severe fungal infection with high mortality rate among immunosuppressed and immunocompetent individuals. Due to limitation of current antifungal treatment, new immunotherapeutic approaches are explored.Methods: This study investigated an immunization strategy utilizing heat-inactivated C. gattii with ArtinM as an adjuvant. C57BL/6 mice were intranasally immunized with heat-killed C. gattii and ArtinM was administrated either before immunization or along with HK-C. gattii. Mice were infected with C. gattii and the efficacy of the immunization protocol was evaluated.Results: Mice that received ArtinM exhibited increased levels of IL-10 and relative expression of IL-23 in the lungs, reduced fungal burden and preserved tissue integrity post-infection.Conclusion: Adjuvant ArtinM improved immunization against C. gattii infection in C57BL/6 mice.

Heterogenous Induction of Blocking Antibodies against Ragweed Allergen Molecules by Allergen Extract-Based Immunotherapy Vaccines.

Currently, allergen-specific immunotherapy (AIT) for ragweed allergy is still based on natural allergen extracts. This study aimed to analyse the ability of four commercially available AIT vaccines (CLUSTOID, TYRO-SIT, POLLINEX Quattro Plus and Diater Depot) regarding their ability to induce IgG antibodies against ragweed pollen allergens in rabbits. Accordingly, the IgG reactivity of AIT-induced rabbit sera was tested for ten different ragweed pollen allergens (Amb a 1, 3, 4, 5, 6, 8, 9, 10, 11 and 12) by an ELISA. Furthermore, the ability of rabbit AIT-specific sera to block allergic patients' IgE binding to relevant ragweed allergens (Amb a 1, 4, 6, 8 and 11) and to inhibit allergen-induced basophil activation was evaluated by an IgE inhibition ELISA and a mediator release assay. Only two AIT vaccines (Diater Depot > CLUSTOID) induced relevant IgG antibody levels to the major ragweed allergen Amb a 1. The IgG responses induced by the AIT vaccines against the other ragweed allergens were low and highly heterogeneous. Interestingly, the kinetics of IgG responses were different among the AIT vaccines and even within one AIT vaccine (Diater Depot) for Amb a 1 (long-lasting) versus Amb a 8 and Amb a 11 (short-lived). This could be due to variations in allergen contents, the immunogenicity of the allergens, and different immunization protocols. The IgE inhibition experiments showed that rabbit AIT-specific sera containing high allergen-specific IgG levels were able to inhibit patients' IgE binding and prevent the mediator release with Diater Depot. The high levels of allergen-specific IgG levels were associated with their ability to prevent the recognition of allergens by patients' IgE and allergen-induced basophil activation, indicating that the measurement of allergen-induced IgG could be a useful surrogate marker for the immunological efficacy of vaccines. Accordingly, the results of our study may be helpful for the selection of personalized AIT vaccination strategies for ragweed-allergic patients.

VCA supercooling in a swine partial hindlimb model

Vascularized composite allotransplantations are complex procedures with substantial functional impact on patients. Extended preservation of VCAs is of major importance in advancing this field. It would result in improved donor-recipient matching as well as the potential for ex vivo manipulation with gene and cell therapies. Moreover, it would make logistically feasible immune tolerance induction protocols through mixed chimerism. Supercooling techniques have shown promising results in multi-day liver preservation. It consists of reaching sub-zero temperatures while preventing ice formation within the graft by using various cryoprotective agents. By drastically decreasing the cell metabolism and need for oxygen and nutrients, supercooling allows extended preservation and recovery with lower ischemia–reperfusion injuries. This study is the first to demonstrate the supercooling of a large animal model of VCA. Porcine hindlimbs underwent 48 h of preservation at − 5 °C followed by recovery and normothermic machine perfusion assessment, with no issues in ice formation and favorable levels of injury markers. Our findings provide valuable preliminary results, suggesting a promising future for extended VCA preservation.

Low-dose M.tb infection but not BCG or MTBVAC vaccination enhances heterologous antibody titres in non-human primates.

Mycobacteria are known to exert a range of heterologous effects on the immune system. The mycobacteria-based Freund's Complete Adjuvant is a potent non-specific stimulator of the immune response used in immunization protocols promoting antibody production, and Mycobacterium bovis Bacille Calmette Guérin (BCG) vaccination has been linked with decreased morbidity and mortality beyond the specific protection it provides against tuberculosis (TB) in some populations and age groups. The role of heterologous antibodies in this phenomenon, if any, remains unclear and under-studied. We set out to evaluate antibody responses to a range of unrelated pathogens following infection with Mycobacterium tuberculosis (M.tb) and vaccination with BCG or a candidate TB vaccine, MTBVAC, in non-human primates. We demonstrate a significant increase in the titer of antibodies against SARS-CoV-2, cytomegalovirus, Epstein-Barr virus, tetanus toxoid, and respiratory syncytial virus antigens following low-dose aerosol infection with M.tb. The magnitude of some of these responses correlated with TB disease severity. However, vaccination with BCG administered by the intradermal, intravenous or aerosol routes, or intradermal delivery of MTBVAC, did not increase antibody responses against unrelated pathogens. Our findings suggest that it is unlikely that heterologous antibodies contribute to the non-specific effects of these vaccines. The apparent dysregulation of B cell responses associated with TB disease warrants further investigation, with potential implications for risk of B cell cancers and novel therapeutic strategies.

Recombinant Human Proteoglycan Aggrecan-G1 Domain-induced Arthritis (GIA) Mouse Model.

The recombinant human proteoglycan aggrecan-G1 domain (rhG1)-induced arthritis (GIA) mouse model is a complex model of rheumatoid arthritis (RA). In GIA, autoimmune arthritis is induced by repeated intraperitoneal immunization of genetically susceptible BALB/c mice with the rhG1 antigen emulsified in the adjuvant dimethyldioctadecylammonium (DDA). This article describes the steps for producing and purifying the rhG1 antigen, the immunization protocol, methods for following the clinical picture of arthritis, and the evaluation of relevant laboratory parameters. In this model, the autoimmune arthritis develops stepwise, similar to RA: First is the preclinical stage (after the first immunization, days 0-20) with no sign of inflammation but detectable T and B cell activation; next, the stage of early arthritis (after the second immunization, days 21-41), where the first definitive signs of arthritis appear together with autoantibody production; and then the severe late-stage arthritis (after the third immunization, after day 42), which presents with massive inflammation of the limbs, leading to cartilage and bone destruction and finally ankylosis. The protocols described here provide sufficient information for investigators to use the GIA model to study different aspects of autoimmune arthritis. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol: Induction of recombinant human proteoglycan aggrecan-G1 domain (rhG1)-induced arthritis (GIA) Support Protocol 1: Production of rhG1-Xa-mFc2a fusion protein with CHOK1 mammalian expression system Support Protocol 2: Purification of the rhG1-Xa-mFc2a fusion protein by affinity chromatography Support Protocol 3: Preparation of DDA adjuvant Support Protocol 4: Clinical assessment of arthritis Support Protocol 5: Measurement of serum antibody levels and cytokines Support Protocol 6: Measurement of rhG1-induced proliferation and cytokine production in spleen cell culture Support Protocol 7: Histological assessment of arthritic limbs Support Protocol 8: Evaluation of arthritis with micro-computed tomography.

The use of Bacillus subtilis as a cost-effective expression system for production of Cholera Toxin B fused factor VIII epitope regions applicable for inducing oral immune tolerance.

Coagulation factor replacement therapy for the X-linked bleeding disorder Haemophilia, characterized by a deficiency of coagulation protein factor VIII (FVIII), is severely complicated by antibody (inhibitors) formation. The development of FVIII inhibitors drastically alters the quality of life of the patients and is associated with a tremendous increase in morbidity as well as treatment costs. The ultimate goal of inhibitor control is antibody elimination. Immune tolerance induction (ITI) is the only clinically established approach for developing antigen-specific tolerance to FVIII. This work aims to establish a novel cost-effective strategy to produce FVIII molecules in fusion with cholera toxin B (CTB) subunit at the N terminus using the Bacillus subtilis expression system for oral tolerance, as the current clinical immune tolerance protocols are expensive. Regions of B-Domain Deleted (BDD)-FVIII that have potential epitopes were identified by employing Bepipred linear epitope prediction; 2 or more epitopes in each domain were combined and cDNA encoding these regions were fused with CTB and cloned in the Bacillus subtilis expression vector pHT43 and expression analysis was carried out. The expressed CTB-fused FVIII epitope domains showed strong binding affinity towards the CTB-receptor GM1 ganglioside. To conclude, Bacillus subtilis expressing FVIII molecules might be a promising candidate for exploring for the induction of oral immune tolerance.

Bacterium-like Particles from Corynebacterium pseudodiphtheriticum as Mucosal Adjuvant for the Development of Pneumococcal Vaccines.

Previously, it was shown that intranasally (i.n.) administered Corynebacterium pseudodiphtheriticum 090104 (Cp) or CP-derived bacterium-like particles (BLPs) improve the immunogenicity of the pneumococcal conjugate vaccine (PCV). This work aimed to deepen the characterization of the adjuvant properties of Cp and CP-derived BLPs for their use in the development of pneumococcal vaccines. The ability of Cp and CP-derived BLPs to improve both the humoral and cellular specific immune responses induced by i.n. administered polysaccharide-based commercial pneumococcal vaccine (Pneumovax 23®) and the chimeric recombinant PSPF (PsaA-Spr1875-PspA-FliC) protein was evaluated, as well as the protection against Streptococcus pneumoniae infection in infant mice. Additionally, whether the immunization protocols, including Cp and CP-derived BLPs, together with the pneumococcal vaccines can enhance the resistance to secondary pneumococcal pneumonia induced after inflammatory lung damage mediated by the activation of Toll-like receptor 3 (TLR3) was assessed. The results showed that both Cp and CP-derived BLPs increased the immunogenicity and protection induced by two pneumococcal vaccines administered through the nasal route. Of note, the nasal priming with the PSPF T-dependent antigen co-administered with Cp or CP-derived BLPs efficiently stimulated humoral and cellular immunity and increased the resistance to primary and secondary pneumococcal infections. The CP-derived BLPs presented a stronger effect than live bacteria. Given safety concerns associated with live bacterium administration, especially in high-risk populations, such as infants, the elderly, and immunocompromised patients, BLPs emerge as an attractive mucosal adjuvant to improve the host response to pneumococcal infections and to enhance the vaccines already in the market or in development.

Trained innate immunity modulates osteoblast and osteoclast differentiation

Macrophages are key regulators in bone repair and regeneration. Recent studies have shown that long-term epigenetic changes and metabolic shifts occur during specific immune training of macrophages that affect their functional state, resulting in heightened (trained) or reduced (tolerant) responses upon exposure to a second stimulus. This is known as innate immune memory. Here, we study the impact of macrophages’ memory trait on osteoblast differentiation of human mesenchymal stromal cells (hMSCs) and osteoclast differentiation. An in vitro trained immunity protocol of monocyte-derived macrophages was employed using inactivated Candida albicans and Bacillus Calmette–Guérin (BCG) to induce a ‘trained’ state and Pam3CSK4 (PAM) and Lipopolysaccharides (LPS) to induce a ‘tolerance’ state. Macrophages were subsequently cocultured with hMSCs undergoing osteogenic differentiation during either resting (unstimulated) or inflammatory conditions (restimulated with LPS). Alkaline phosphatase activity, mineralization, and cytokine levels (TNF, IL-6, oncostatin M and SDF-1α) were measured. In addition, macrophages underwent osteoclast differentiation. Our findings show that trained and tolerized macrophages induced opposing results. Under resting conditions, BCG-trained macrophages enhanced ALP levels (threefold), while under inflammatory conditions this was found in the LPS-tolerized macrophages (fourfold). Coculture of hMSCs with trained macrophages showed mineralization while tolerized macrophages inhibited the process under both resting and inflammatory conditions. While osteoclast differentiation was not affected in trained-macrophages, this ability was significantly loss in tolerized ones. This study further confirms the intricate cross talk between immune cells and bone cells, highlighting the need to consider this interaction in the development of personalized approaches for bone regenerative medicine.Graphical

One-point evaluation of children exposed to rubella infection In Utero in Maiduguri, North-Eastern Nigeria: A follow-up Study

Background: Rubella is a disease caused by a virus, rubella virus. Major obstetrics concerns are profound effects of the virus on developing fetuses, which may result in multiple congenital malformations. Although vaccination has reduced the incidence of rubella virus substantially; the World Health Organization (WHO) estimated that more than 100,000 cases of congenital rubella syndrome occur each year worldwide, most of them in developing countries. Diagnosis of rubella cannot be made on clinical grounds alone due to lack of specific symptoms or signs that are unique to the disease. Women infected with rubella during pregnancy are at increased risk of developing complication for the women and their fetuses. Some of these complications may not present at birth, but several years during childhood and later in life. Methodology: The main rubella sero-prevalence study was conducted in 2013, at the Department of Obstetrics and Gynaecology of the University of Maiduguri Teaching Hospital (UMTH), Maiduguri, Borno State, North-Eastern Nigeria. This is a follow-up descriptive study. The children of women who had significant titres of Immunoglobulin M antibodies, and who were negative for Immunoglobulin G antibodies were followed during their pregnancies and childbirth. The children born to these women who acquired rubella virus infection in mid pregnancy were reviewed at 10-11 years of age, and their current state of health is reported. Their biodata, educational status, rubella serostatus, state of health, and history of vaccination with measles were obtained. Results: There were 459 pregnant women who consented and participated in the main sero-prevalence study. Four hundred twenty-one women (91.7%) women tested positive for rubella-specific IgG antibodies, and of the remaining 38 women, 6 (15.8%) were positive for IgM rubella-specific antibody. All the patients with positive IgM antibodies were followed up till birth. All the pregnancies were carried to term and delivered in hospital. None of the neonates was found to have any congenital malformation at birth. At 10 years review of the six (6) children, 1 (16.7%) child developed cataract. None of the children developed cardiac, ear, or other complications of rubella. Five (5) children (83.3%) tested positive for both IgG, one (1) was negative (the child with cataract) for rubella antibodies. None had IgM rubella antibodies. All the children were enrolled in schools and their performance is at least average of their peers. Conclusion: None of the known types of congenital rubella syndrome was found in this study, this may be as a result of smaller number of infected pregnancies. It is recommended that inclusion of rubella vaccination in the National programme on Immunization protocol will be cost effective in the prevention of rubella-associated complication in children.