Recombinant IgG Research Articles

Simultaneous Protein Quantitation and Glycosylation Profiling of Antigen-Specific Immunoglobulin G1 in Large Clinical Studies.

Antibodies have a key role in the immune system, making their characterization essential to biomedical, biopharmaceutical, and clinical research questions. Antibody effector functions are mainly controlled by quantity, subclass, and Fc glycosylation. We describe an integrated method to measure these three critical dimensions simultaneously. The subclass-specific immunoglobulin G (IgG) Fc glycosylation analysis combines immunosorbance with glycopeptide-centered LC-MS detection. For integrated IgG1-specific quantitation, a commercial, stable isotope labeled IgG1 protein standard was spiked into the immunosorbent eluates. Robust quantitation was achieved, relying on a combination of a proteotypic peptide and the most abundant glycopeptides, generated through proteolytic cleavage from a mixture of natural IgG1 and the recombinant IgG1 standard. Method performance was demonstrated in a large coronavirus vaccination cohort at a throughput of 100 samples/day. LC-MS-derived, anti-SARS-CoV-2 spike protein IgG1 concentrations ranged from 100 to 10000 ng/mL and correlated well with a clinically relevant immunoassay. Technical variation was 200 times lower than biological variation; intermediate precision was 44%. In conclusion, we present a method capable of robustly and simultaneously assessing quantity, subclass, and Fc glycosylation of antigen-specific IgG in large clinical studies. This method will facilitate a broader understanding of immune responses, especially the important interplay among the three dimensions.

Infusion Reactions to Infliximab in Pediatric Patients with Inflammatory Bowel Disease

Infliximab (IFX) is a recombinant DNA-derived chimeric IgG monoclonal antibody protein that inhibits tumor necrosis factor alpha (TNF-α). IFX, like other agents derived from foreign proteins, can cause infusion reactions both during and after the infusion. The incidence of infusion reactions ranges between 0% and 15% in pediatric patients. The potential underlying mechanisms for these reactions may include anaphylaxis and anaphylactoid reactions, cytokine release syndrome, serum sickness-like reactions, and the development of antibodies against IFX. Several precautions can help reduce the risk of a new infusion reaction, such as a gradual increase in the infusion rate, scheduled infusions, and administering premedication or immunomodulators alongside IFX. Acute mild to moderate reactions often resolve spontaneously after a temporary cessation of the infusion or reduction in the infusion rate. Strategies like graded dose challenges and premedication can be utilized to prevent recurrence. In cases of severe reactions, desensitization or switching to an alternative biologic may be considered. This article aims to review the most recent guidelines for managing IFX-related infusion reactions in pediatric patients with inflammatory bowel disease (IBD), relying on the best available evidence.

Development of bovine IgG3-specific assays using a novel recombinant single-domain binding reagent

Cattle express three subclasses of IgG antibody - IgG1, IgG2 and IgG3. Unlike IgG1 and IgG2, IgG3 was described relatively recently and the role of this subclass in immunity is unknown. Using recombinant bovine IgG1, IgG2 and IgG3 monoclonal antibodies (mAbs), we demonstrated that only one of the commercially available anti-bovine IgG mAbs tested was able to recognize IgG3, and no mAb exclusively bound IgG3. Here, we evaluated a small ankyrin repeat protein, called Ankyron™ AZS40101, that was generated to bind to bovine IgG3. Ankyron™ AZS40101 bound specifically to IgG3 with minimal reactivity to IgG1 and IgG2. Ankyron™ AZS40101 was shown to be useful in ELISA assays as either a capture or detection reagent. Utilisation of Ankyron™ AZS40101 alongside IgG1 and IgG2 specific mAbs to detect antigen-specific IgG subclasses in the serum of cattle sequentially vaccinated with heterologous foot-and-mouth disease virus capsid antigens revealed a low-level antigen-specific IgG3 response, in addition to IgG1 and IgG2 responses. Assessment of the total IgG1, IgG2 and IgG3 levels in healthy cattle plasma samples showed that IgG3 was measurable at a mean concentration of 0.19mg/mL, although this was significantly lower than those of IgG1 (mean 3.28mg/mL) and IgG2 (mean 3.41mg/mL). Thus, Ankyron™ AZS40101 is a new reagent that provides utility for measurement of bovine IgG3 responses to infection and vaccination.

Modular Semisynthetic Approach to Generate T Cell-Dependent Bispecific Constructs from Recombinant IgG1 Antibodies.

Redirecting T cells to tumor cells by bispecific antibodies is an effective approach to treat cancer, and T cell-dependent bispecific antibodies (TDBAs) are an emerging class of potent immunotherapeutic agents. By simultaneously targeting antigens on tumor cells and T cells, T cells are activated to kill tumor cells. Herein, we report a platform to generate a novel class of 2:1 structure of T cell-dependent bispecific antibody with bivalency for HER2 receptors on tumor cells and monovalency for CD3 receptors on T cells. For this, we use a biogenic inverse electron-demand Diels-Alder (IEDDA) click reaction on genetically encoded tyrosine residues to install one TCO handle on therapeutically approved antibody trastuzumab. Subsequent TCO-tetrazine click with a tetrazine-functionalized CD3-binding Fab yields a 2:1 HER2 × CD3 TDBA that exhibits a tumor-killing capability at picomolar concentrations. Monovalency toward the CD3 receptor on T cells can lower the chances of cytokine release syndrome, which is a common side effect of such agents. Our semisynthetic approach can generate highly potent TDBA constructs in a few chemoenzymatic and synthetic steps.

Abstract P389: Immunogenic Peptides Responsible for Experimental Hypertension Contribute to Systemic Lupus Erythematosus

Introduction: Hypertension and systemic lupus erythematosus (SLE) lead to modification of self-peptides by isolevuglandin (isoLG) lipid oxidation products. These self-peptides are presented by class 1 major histocompatibility complexes and drive CD8 + T cell activation. We have identified self-peptides from the sodium/glucose cotransporter2 (SGLT2); cadherin 16; Kelch domain-containing protein 7A and solute carrier family 23 that are IsoLG-adducted and cause CD8 + T cell activation in both ang II and L-NAME/high salt models of hypertension. These prime hypertension in response to low dose ang II. Hypothesis: We hypothesized that the same immunogenic peptides responsible for experimental hypertension contribute to systemic lupus erythematosus. Methods: A fluorescent probe made of recombinant IgG and the murine class 1 MHC H2-D b was loaded with either unadducted SGLT2 peptide or an isoLG-adducted SGLT2 peptide. This probe was used in flow cytometry to detect CD8 + T cells specific for this peptide antigen in 12-week-old C57Bl/6 and female B6SLE1.2.3 mice. Results: The unadducted SGLT2 probe recognized < 1% of CD8 + T cells (Figure). In contrast, ang II-infusion caused a striking increase in IsoLG-SGLT2 specific CD8 + T cells in C57Bl/6 aortas (Figure panels A and D). In C57Bl/6 very few CD8 + T cells recognizing IsoLG-SGLT2 were observed in the spleen (Panel B and E). Importantly, from 5 to 20% of CD8 + T cells in spleens of female B6SLE1.2.3 mice recognized the IsoLG-SGLT2 peptide (Figure panels C and E). Image 1. Conclusions: These findings strongly suggest that IsoLG-adducted peptides responsible for ang II-induced hypertension contribute to SLE and suggest that these conditions share similar immunogenicity.

Preclinical efficacy of peanut-specific IgG4 antibody therapeutic IGNX001

BackgroundExisting therapeutic strategies are challenged by long times to achieve effect and often require frequent administration. Peanut allergic individuals would benefit from a therapeutic that provides rapid protection against accidental exposure within days of administration while carrying little risk of adverse reactions. ObjectiveGuided by the repertoire of human IgE monoclonal antibodies (mAbs) from allergic individuals, we sought to develop a treatment approach leveraging the known protective effects of allergen-specific IgG4 antibodies. MethodsWe applied our single-cell RNA sequencing SEQ SIFTER™ platform to whole blood samples from peanut allergic individuals to discover IgE mAbs. These were then class-switched by replacing the IgE constant region with IgG4 while retaining the allergen-specific variable regions. In vitro mast cell activation tests (MATs), basophil activation tests (BATs), enzyme-linked immunosorbent assays (ELISAs), and an in vivo peanut allergy mouse model were used to evaluate the specificity, affinity, and activity of these recombinant IgG4 mAbs. ResultsWe determined that human peanut-specific IgE mAbs predominantly target immunodominant epitopes on Ara h 2 and Ara h 6 and that recombinant IgG4 mAbs effectively blocked these epitopes. IGNX001, a mixture of two such high-affinity IgG4 mAbs, provided robust protection against peanut-mediated mast cell activation in vitro as well as against anaphylaxis upon intragastric peanut challenge in a peanut allergy mouse model. ConclusionWe developed a peanut-specific IgG4 antibody therapeutic with convincing preclinical efficacy starting from a large repertoire of human monoclonal IgE antibodies from demographically and geographically diverse individuals. These results warrant further clinical investigation of IGNX001 and underscore the opportunity for the application of this therapeutic development strategy in other food and environmental allergies.

Efficacy and Safety of BP02 (Trastuzumab Biosimilar) in HER2-Positive Metastatic Breast Cancer: A Multicenter Phase III Study.

Trastuzumab targets human epidermal growth factor receptor 2 (HER2) receptors and is indicated for treating HER2-positive metastatic breast cancer. BP02,a recombinant IgG1 kappa humanized monoclonal antibody, is being developed as atrastuzumab biosimilar. The objective of this study was to evaluate the equivalence of BP02 with reference trastuzumab (RT: Herceptin®-EU) in patients withHER2-positive metastatic breast cancer. This double-blinded, 1:1 randomized, parallel-group, active-controlled, phase III equivalence trial recruited women aged 18-75 years with histologically/cytologically confirmed HER2- positive, locally recurrent or metastatic breast cancer with systemic metastasis, from 59 sites in India. Patients were randomly allocated 1:1 stratified by estrogen receptor/progesterone receptor status to receive BP02/RT (8-mg/kg loading dose on day 1-cycle 1, 6 mg/kg on day 1-cycles 2-8, of each 3-week cycle) combined with docetaxel (75mg/m2 on day 1-cycles 1-8) [induction phase]. Participants with complete or partial response, or stable disease at the end of the induction phase continued the study drug until disease progression/treatment discontinuation [maintenance phase]. The primary efficacy endpoint was the objective response rate per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Between 23 September, 2020 and 16 September, 2022, 690 patients were recruited (n = 345 each to BP02/RT). At the end of the induction phase (intent-to-treat population), a similar proportion of patients achieved an objective response rate with BP02 (n = 231 [67.0%], 95% confidence interval [CI] 62.0, 71.9) and RT (n = 238 [69.0%], 95% CI 64.1, 73.9). The 95% CI of risk difference (-2.03, 95% CI -9.15, 5.09) and 90% CI of risk ratio (0.97, 90% CI 0.89, 1.06) were within equivalence margins of ±13% and (0.80, 1.25), respectively. Treatment-emergent adverse events leading to treatment withdrawal were reported in 2.9% and 3.2% patients with BP02 and RT, respectively. BP02 showed an equivalent efficacy and similar safety profile to RT at the end of 24 weeks. CTRI Number: CTRI/2020/04/024456.

Reconstruction of Sjögren's syndrome-like sialadenitis by a defined disease specific gut-reactive single TCR and an autoantibody

Lymphocytes such as CD4+ T cells and B cells mainly infiltrate the salivary glands; however, the precise roles and targets of autoreactive T cells and autoantibodies in the pathogenesis of Sjögren's Syndrome (SS) remain unclear. This study was designed to clarify the role of autoreactive T cells and autoantibodies at the single-cell level involved in the development of sialadenitis. Infiltrated CD4+ T and B cells in the salivary glands of a mouse model resembling SS were single-cell-sorted, and their T cell receptor (TCR) and B cell receptor (BCR) sequences were analyzed. The predominant TCR and BCR clonotypes were reconstituted in vitro, and their pathogenicity was evaluated by transferring reconstituted TCR-expressing CD4+ T cells into Rag2−/− mice and administering recombinant IgG in vivo. The reconstitution of Th17 cells expressing TCR (#G) in Rag2−/− mice resulted in the infiltration of T cells into the salivary glands and development of sialadenitis, while an autoantibody (IgGr22) was observed to promote the proliferation of pathogenic T cells. IgGr22 specifically recognizes double-stranded RNA (dsRNA) and induces the activation of dendritic cells, thereby enhancing the expression of IFN signature and inflammatory genes. TCR#G recognizes antigens related to the gut microbiota. Antibiotic treatment severely reduces the activation of TCR#G-expressing Th17 cells and suppresses sialadenitis development. These data suggest that the anti-dsRNA antibodies and, TCR recognizing the gut microbiota involved in the development of sialadenitis like SS. Thus, our model provides a novel strategy for defining the roles of autoreactive TCR and autoantibodies in the development and pathogenesis of SS.

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

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

Sparsentan ameliorates glomerular hypercellularity and inflammatory-gene networks induced by IgA1-IgG immune complexes in a mouse model of IgA nephropathy.

IgA nephropathy (IgAN) is characterized by glomerular deposition of immune complexes (ICs) consisting of IgA1 with O-glycans deficient in galactose (Gd-IgA1) and Gd-IgA1-specific IgG autoantibodies. These ICs induce kidney injury, and in the absence of disease-specific therapy, up to 40% of patients with IgAN progress to kidney failure. IgA1 with its clustered O-glycans is unique to humans, which hampered development of small-animal models of IgAN. Here, we used a model wherein engineered ICs (EICs) formed from human Gd-IgA1 and recombinant human IgG autoantibody are injected into nude mice to induce glomerular injury mimicking human IgAN. In this model, we assessed the protective effects of sparsentan, a single-molecule dual endothelin angiotensin receptor antagonist (DEARA) versus vehicle on EIC-induced glomerular proliferation and dysregulation of gene expression in the kidney. Oral administration of sparsentan (60 or 120 mg/kg daily) to mice intravenously injected with EIC attenuated the EIC-induced glomerular hypercellularity. Furthermore, analysis of changes in the whole kidney transcriptome revealed that key inflammatory and proliferative biological genes and pathways that are upregulated in this EIC model of IgAN were markedly reduced by sparsentan, including complement genes, integrin components, members of the mitogen-activated protein kinase family, and Fc receptor elements. Partial overlap between mouse and human differentially expressed genes in IgAN further supported the translational aspect of the immune and inflammatory components from our transcriptional findings. In conclusion, our data indicate that in the mouse model of IgAN, sparsentan targets immune and inflammatory processes leading to protection from mesangial hypercellularity.NEW & NOTEWORTHY The mechanisms by which deposited IgA1 immune complexes cause kidney injury during early phases of IgA nephropathy are poorly understood. We used an animal model we recently developed that involves IgA1-IgG immune complex injections and determined pathways related to the induced mesangioproliferative changes. Treatment with sparsentan, a dual inhibitor of endothelin type A and angiotensin II type 1 receptors, ameliorated the induced mesangioproliferative changes and the associated alterations in the expression of inflammatory genes and networks.

Dual CTLA-4 and PD-1 checkpoint blockade using CS1002 and CS1003 (nofazinlimab) in patients with advanced solid tumors: A first-in-human, dose-escalation, and dose-expansion study.

This study investigated the safety and efficacy of an anti-CTLA-4 monoclonal antibody (CS1002) as monotherapy and in combination with an anti-PD-1 monoclonal antibody (CS1003) in patients with advanced/metastatic solid tumors. The phase 1 study involved phase 1a monotherapy dose-escalation (part 1) and phase 1b combination therapy dose escalation (part 2) and expansion (part 3). Various dosing schedules of CS1002 (0.3, 1, or 3mg/kg every 3 weeks, or 3mg/kg every 9 weeks) were evaluated with 200mg CS1003 every 3 weeks in part 3. Parts 1, 2, and 3 included a total of 13, 18, and 61 patients, respectively. No dose-limiting toxicities or maximum tolerated doses were observed. Treatment-related adverse events (TRAEs) were reported in 30.8%, 83.3%, and 75.0% of patients in parts 1, 2, and 3, respectively. Grade ≥3 TRAEs were experienced by 15.4%, 50.0%, and 18.3% of patients in each part. Of 61 patients evaluable for efficacy, 23 (37.7%) achieved objective responses in multiple tumor types. Higher objective response rates were observed with conventional and high-dose CS1002 regimens (1mg/kg every 3 weeks or 3mg/kg every 9 weeks) compared to low-dose CS1002 (0.3mg/kg every 3 weeks) in microsatellite instability-high/mismatch repair-deficient tumors, melanoma, and hepatocellular carcinoma (50.0% vs. 58.8%, 14.3% vs. 42.9%, and 0% vs. 16.7%). CS1002, as monotherapy, and in combination with CS1003, had a manageable safety profile across a broad dosing range. Promising antitumor activities were observed in patients with immune oncology (IO)-naive and IO-refractory tumors across CS1002 dose levels when combined with CS1003, supporting further evaluation of this treatment combination for solid tumors. CS1002 is a human immunoglobulin (Ig) G1 monoclonal antibody that blocks the interaction of CTLA-4 with its ligands and increases T-cell activation/proliferation. CS1003, now named nofazinlimab, is a humanized, recombinant IgG4 monoclonal antibody that blocks the interaction between human PD-1 and its ligands. In this original article, we determined the safety profile of CS1002 as monotherapy and in combination with CS1003. Furthermore, we explored the antitumor activity of the combination in anti-programmed cell death protein (ligand)-1 (PD-[L]1)-naive microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) pan tumors, and anti-PD-(L)1-refractory melanoma and hepatocellular carcinoma (HCC). CS1002 in combination with CS1003 had manageable safety profile across a broad dosing range and showed promising antitumor activities across CS1002 dose levels when combined with CS1003. This supports further assessment of CS1002 in combination with CS1003 for the treatment of solid tumors.

High-resolution map of the Fc functions mediated by COVID-19-neutralizing antibodies.

A growing body of evidence shows that fragment crystallizable (Fc)-dependent antibody effector functions play an important role in protection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. To unravel the mechanisms that drive these responses, we analyzed the phagocytosis and complement deposition mediated by a panel of 482 human monoclonal antibodies (nAbs) neutralizing the original Wuhan virus, expressed as recombinant IgG1. Our study confirmed that nAbs no longer neutralizing SARS-CoV-2 Omicron variants can retain their Fc functions. Surprisingly, we found that nAbs with the most potent Fc function recognize the N-terminal domain, followed by those targeting class 3 epitopes in the receptor binding domain. Interestingly, nAbs direct against the class 1/2 epitopes in the receptor binding motif, which are the most potent in neutralizing the virus, were the weakest in Fc functions. The divergent properties of the neutralizing and Fc function-mediating antibodies were confirmed by the use of different B cell germlines and by the observation that Fc functions of polyclonal sera differ from the profile observed with nAbs, suggesting that non-neutralizing antibodies also contribute to Fc functions. These data provide a high-resolution picture of the Fc-antibody response to SARS-CoV-2 and suggest that the Fc contribution should be considered for the design of improved vaccines, the selection of therapeutic antibodies, and the evaluation of correlates of protection.

Conversion of Mouse-Derived Hybridomas to Tasmanian Devil Recombinant IgG Antibodies.

The hybridoma method for production of monoclonal antibodies has been a cornerstone of biomedical research for several decades. Here we convert the monoclonal antibody sequence from mouse-derived hybridomas into a "devilized" recombinant antibody with devil IgG heavy chain and IgK light chain. The chimeric recombinant antibody can be used in functional assays, immunotherapy, and to improve understanding of antibodies and Fc receptors in Tasmanian devils. The process can be readily modified for other species.

Antibody engineering to generate anti-tumor-associated glycoprotein 72 mouse recombinant CC49 IgG with improved solubility, purity, and thermal stability

Tumor-associated glycoprotein 72 (TAG-72) is a mucin that is overexpressed heterogeneously on the surface of cancer cells, and is a potential target for immunotherapies for various cancer types. As a tumor marker, TAG-72 is measured with the cancer antigen (CA) 72–4 immunoassay. The murine monoclonal antibody (mAb) CC49 is a second-generation IgG that targets an antigen on TAG-72; however, CC49 has an unfavorable propensity to aggregate, which results in antibody impurity, instability, and low solubility and thus low potency and efficacy for therapeutic and diagnostic applications. Sequence analysis of CC49 revealed aggregation-prone motifs in the variable domain of the light chain. Using antibody engineering approaches, we developed three aggregation-resistant CC49 mIgG2a mutants (CC49M1, CC49M2, and CC49M3). The engineered CC49 mIgG2a mutants retained compatible binding performance with a significantly higher thermal stability. The CC49 mIgG2a mutants also demonstrated an almost 15-fold improvement in solubility, with 97% purity vs 70% purity of the parent molecule at 0.3 mg/mL. The enhanced stability and improved solubility of engineered CC49 could have significant advantages for diagnostic and therapeutic applications.

Site-directed neutralizing antibodies targeting structural sites on SARS-CoV-2 spike protein

‘Epivolve’ (epitope evolution) is an innovative paratope-evolving technology using a haptenated peptide or protein immunogen as a means of directing the in vivo immune response to specifically targeted sites at a one amino acid residue resolution. Guided by protein structural analysis, Epivolve technology was tested to develop site-directed neutralizing antibodies (nAbs) in a systematic fashion against the SARS-CoV-2 Receptor Binding Domain (RBD). Thirteen solvent-exposed sites covering the ACE2 receptor-binding interface were targeted. Immunogens composed of each targeted site were used to immunize rabbits in separate cohorts. In vivo site-directed immune responses against all 13 targets were demonstrated by B cell secreted IgG and recombinant IgG testing. One site, SL13 (Y505) which mutates from tyrosine to histidine in the SARS-CoV-2 Omicron variant, was chosen as a proof-of-concept (PoC) model for further functional monoclonal antibody development. Epivolve technology demonstrated the capabilities of generating pan-variant antibodies and nAbs against the SARS-CoV-2 primary strain and the Omicron variant.

Interim results from a phase I randomized, placebo-controlled trial of novel SARS-CoV-2 beta variant receptor-binding domain recombinant protein and mRNA vaccines as a 4th dose booster

SARS-CoV-2 booster vaccination should ideally enhance protection against variants and minimise immune imprinting. This Phase I trial evaluated two vaccines targeting SARS-CoV-2 beta-variant receptor-binding domain (RBD): a recombinant dimeric RBD-human IgG1 Fc-fusion protein, and an mRNA encoding a membrane-anchored RBD. 76 healthy adults aged 18-64y, previously triple vaccinated with licensed SARS-CoV-2 vaccines, were randomised to receive a 4th dose of either an adjuvanted (MF59®, CSL Seqirus) protein vaccine (5, 15 or 45μg, N=32), mRNA vaccine (10, 20, or 50μg, N=32), or placebo (saline, N=12) at least 90 days after a 3rd boost vaccination or SARS-CoV-2 infection. Bleeds occurred on days 1 (prior to vaccination), 8, and 29. govNCT05272605. No vaccine-related serious or medically-attended adverse events occurred. The protein vaccine reactogenicity was mild, whereas the mRNA vaccine was moderately reactogenic at higher dose levels. Best anti-RBD antibody responses resulted from the higher doses of each vaccine. A similar pattern was seen with live virus neutralisation and surrogate, and pseudovirus neutralisation assays. Breadth of immune response was demonstrated against BA.5 and more recent omicron subvariants (XBB, XBB.1.5 and BQ.1.1). Binding antibody titres for both vaccines were comparable to those of a licensed bivalent mRNA vaccine. Both vaccines enhanced CD4+ and CD8+ T cell activation. There were no safety concerns and the reactogenicity profile was mild and similar to licensed SARS-CoV-2 vaccines. Both vaccines showed strong immune boosting against beta, ancestral and omicron strains. Australian Government Medical Research Future Fund, and philanthropies Jack Ma Foundation and IFM investors.

Pathogenic myelin-specific antibodies in multiple sclerosis target conformational proteolipid protein 1-anchored membrane domains.

B cell clonal expansion and cerebrospinal fluid (CSF) oligoclonal IgG bands are established features of the immune response in multiple sclerosis (MS). Clone-specific recombinant monoclonal IgG1 Abs (rAbs) derived from MS patient CSF plasmablasts bound to conformational proteolipid protein 1 (PLP1) membrane complexes and, when injected into mouse brain with human complement, recapitulated histologic features of MS pathology: oligodendrocyte cell loss, complement deposition, and CD68+ phagocyte infiltration. Conformational PLP1 membrane epitopes were complex and governed by the local cholesterol and glycolipid microenvironment. Abs against conformational PLP1 membrane complexes targeted multiple surface epitopes, were enriched within the CSF compartment, and were detected in most MS patients, but not in inflammatory and noninflammatory neurologic controls. CSF PLP1 complex Abs provide a pathogenic autoantibody biomarker specific for MS.

Briumvi: a breakthrough in the treatment of relapsing multiple sclerosis: a review.

Multiple sclerosis (MS) is a chronic systemic autoimmune disorder characterized by plaques of demyelination, autoimmune inflammation, and astrocytic gliosis. The primary cells involved in the pathophysiology of MS are T cells. However, B cells have recently been implicated in the pathophysiology of the disease. Therefore, researchers have been exploring B cell therapy as an alternative treatment option for MS. B cell therapy is based on the targeted depletion of CD20-positive B cells. Rituximab, ocrelizumab, and ofatumumab are anti-CD20 antibodies already approved. Briumvi, the fourth type of anti-CD20 antibody was approved by FDA in December 2022, for the treatment of relapsing types of MS, including relapsing-remitting multiple sclerosis, active secondary progressive multiple sclerosis, and clinically isolated syndromes after the drug was tested in two randomized, double-blind, phase III, ULTIMATE I, and II trials which compared Briumvi (ublituximab) with Aubiago (teriflunomide). Ublituximab was found to have a much lower annual relapse rate in the ULTIMATE II trials than teriflunomide. Briumvi is a chimeric recombinant IgG1 monoclonal antibody directed against human CD20 with potential antineoplastic activity. Its mechanism of action involves several distinct processes that collectively lead to the depletion of B cells and suppression of the immune response. The primary mode of action of Briumvi is its high-affinity binding to CD20. Infusion-related reactions are the most common side effects encountered following intravenous administration of ublituximab.

Donepezil to lecanemab-advancements in targeted therapy of Alzheimer’s disease so far

Alzheimer's disease (AD) first identified as Alois Alzheimer in 1907, is a slowly progressing dementia that affects cognition, behaviour and functional status. There is no cure for AD since precise pathophysiological mechanisms underlying it is not completely known. Drugs may temporarily reduce the symptoms associated with disorder, but condition is ultimately fatal. Objective of treatment of AD is to reduce behaviour issues associated with memory loss and improve cognition. Single acetylcholinesterase inhibitors donepezil and galantamine, as well as the dual AChE and butyrylcholinesterase (BuChE) inhibitor rivastigmine, are now utilized in treatment of AD. Cholinesterase inhibitors have shown dose-dependent impact on cognition and functional activities in clinical trials. Memantine NMDA receptor antagonist is used to minimize neurotoxicity that's suspected to contribute to conditions like Alzheimer's and other neurodegenerative disorders. Estrogen administration post menopause can result in modulation of synaptogenesis, enhanced cerebral blood flow, mediation of crucial neurotransmitters and hormones, protection against apoptosis. Aducanumab is 1st disease modifying drug and monoclonal antibody that targets beta-amyloid clusters in mild AD. Recent advancement in therapy, lecanemab, a recombinant IgG1 monoclonal antibody is targeted against aggregated soluble and insoluble forms of amyloid beta, thereby minimizing Aβ plaques and preventing Aβ deposition in the brain. As research advances, molecular basis of disease becomes more apparent leading to the advent of plausible targeted therapy.

Real-world outcomes of mepolizumab treatment in severe eosinophilic asthma patients - retrospective cohort study in Slovakia.

Mepolizumab, a fully-humanized recombinant IgG1 kappa monoclonal antibody directed against IL-5, has shown improved asthma control and lung function in randomised controlled trials. The aim of this study was to evaluate real-world clinical experience in patients with severe eosinophilic asthma treated with mepolizumab in Slovakia. A retrospective, non-interventional study based on medical records of all adult asthma patients initiating mepolizumab between November 1, 2017 and January 31, 2019, completing 12 months of treatment. At baseline, general and clinical profile data were recorded 12 months prior to treatment. Primary and secondary endpoints described the results of mepolizumab use at 2, 6, and 12 months after the initiation and compared to baseline. Statistical testing of individual change (in each patient) in selected parameters was performed. The cohort included 17 patients with particularly severe asthma at baseline, with frequent severe exacerbations (SE, median 5 [IQR 4-6]/patient/year), high blood eosinophil counts (median 0.6x109/L), frequent oral corticosteroid (OCS) dependence (82.35%), median dose 15 (IQR 7.5-20) mg/day, impaired lung function, and a spectrum of comorbidities. In a one-year follow-up, the data showed reductions in median SE (0 [IQR 0-1] patient/year, eosinophilia (median 0.175x109/L) and OCS maintenance dose (median 6.25 [IQR 2.5-20] mg/day), all statistically significant after 12 months on mepolizumab. Improved and stabilised lung functions throughout the cohort and a reduced incidence of nasal polyposis were observed. The results provide clinical evidence of mepolizumab efficacy in a real sample of patients with severe asthma when administered in routine care settings in Slovakia.