Search Results (67)

Background/Objectives: Anti-drug antibody (ADA) formation can impact the safety, pharmacokinetics, and/or efficacy of biotherapeutics, including monoclonal antibodies (mAbs). Current strategies for ADA/immunogenicity risk prediction of mAbs include in silico algorithms, T cell proliferation assays, MHC-associated peptide proteomics assays (MAPPs), and dendritic cell internalization assays. However, B cell-mediated responses are not assessed in these assays. B cells are professional antigen-presenting cells (APCs) and secrete antibodies toward immunogenic mAbs. Therefore, methods to determine B cell responses would be beneficial for immunogenicity risk prediction and may provide a more comprehensive assessment of risk. Methods: We used a PBMC culture method with the addition of IL-4, IL-21, B cell activating factor (BAFF), and an anti-CD40 agonist mAb to support B cell survival and activation. Results: B cells in this assay format become activated, proliferate, and secrete IgG. A panel of 51 antibodies with varying clinical immunogenicity rates were screened in this assay with IgG secretion used as a readout for immunogenicity risk. IgG secretion differed among test articles but did not correlate with the clinical immunogenicity rating. Conclusions: This dataset highlights the challenges of developing a B cell assay for immunogenicity risk prediction and provides a framework for further refinement of a B cell-based assay for immunogenicity risk prediction of mAbs. Full article

SLE is characterized by the generation of a variety of autoantibodies including anti-dsDNA autoantibodies, causing damage in various organs. If autoimmunity is defined by the generation of a variety of autoantibodies against the self, SLE is the only disease to qualify. Identification of the SLE-causing factor must fulfill the following criteria: (i) the factor induces SLE, (ii) the factor is operating in active SLE and (iii) SLE heals after removal of the factor. All candidate factors are reviewed from this viewpoint in this review. As to the cause of SLE, high levels of interferon α can induce SLE; however, interferon α in most patients did not reach this high level. BAFF (B cell activating factor of the TNF family) is increased in SLE. BAFF itself induced some manifestation of SLE, whereas removal of interferon α or BAFF by an antibody (Ab) did not heal SLE. BXSB male mice with a duplicated TLR7 gene develop SLE; however, the gene Sle1 is also required for the development of SLE. In addition, sanroque mice develop a variety of autoantibodies and SLE; the sanroque mutation, which disrupts one of the repressors of ICOS, results in increased CCR7^lo CXCR5⁺Tfh cells, IL-21 and SLE. ICOS⁺T follicular helper (Tfh) cells increase in SLE and SLE-model (NZBxNZW)F1 mice, and the blockade of Tfh development ameliorated SLE, indicating the importance of Tfh cells in the pathogenesis of SLE. Self-organized criticality theory shows that SLE is caused by repeated infection, wherein SLE-inducing pathogens can vary individually depending on one’s HLA; however, the pathogen presented on HLA stimulates the T cell receptor (TCR) strongly beyond self-organized criticality. This stimulation generates TCR-revised, autoreactive DOCK8⁺Tfh cells, which induced a variety of autoantibodies and SLE. The SARS-CoV-2 virus is an example pathogen because SLE occurs after SARS-CoV-2 infection and vaccination. DOCK8⁺Tfh cells and SLE decreased after conventional or anti-DOCK Ab therapies. Thus, DOCK8⁺Tfh cells newly generated after repeated infection fulfill the criteria (i), (ii) and (iii) as the cause of SLE. Full article

Respiratory syncytial virus (RSV) is a major etiological agent of lower respiratory tract infections, particularly among infants and the elderly. Activation of B cells in the mucosa and the production of specific neutralizing antibodies are essential for protective immunity against pulmonary infection. B-cell activating factor (BAFF) is a critical survival factor for B cells and has been associated with antiviral responses; however, its regulation during RSV infection remains poorly understood. This study examined BAFF regulation in BEAS-2B cells exposed to RSV or IFN-β. The treatments resulted in a progressive increase in gene expression over time, accompanied by higher protein levels. BAFF mRNA peaked at 12 h post-infection and declined by 48 h, coinciding with the release of soluble BAFF protein into the culture supernatant. Pre-treatment with anti-IFN-β antibodies prior to RSV infection reduced both BAFF mRNA and protein levels, indicating that IFN-β plays a regulatory role in BAFF production by airway epithelial cells. Western blot analysis revealed membrane-bound BAFF (~31 kDa) in non-infected cells, with elevated expression at 24 h post-infection. By 48 h, this form was cleaved into a soluble ~17 kDa form, which was detected in the supernatant. Immunostaining further demonstrated reduced surface expression of membrane-bound BAFF in RSV-infected cells compared to uninfected controls, suggesting that RSV infection promotes the cleavage and release of BAFF into the extracellular environment. Additionally, the release of BAFF was not affected by furin convertase inhibition or ER–Golgi transport blockade, indicating a potentially novel cleavage mechanism. Co-culturing BAFF produced by BEAS-2B cells with isolated B cells enhanced B cell viability. Overall, these results indicate that RSV infection stimulates BAFF production in airway epithelial cells through a pathway involving IFN-β, potentially contributing to B cell activation and promoting local antibody-mediated immunity. Understanding this mechanism may offer valuable insights for improving mucosal vaccine strategies and enhancing immunity against respiratory pathogens. Full article

Background: Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease characterized by the proteolytic breakdown of the extracellular matrix. A clinical biomarker is needed for risk stratification and prognosis. Methods: In this single-center, 5-year observational study, 452 patients were enrolled: 343 with AAA (≥3 cm), and 109 controls (<3 cm). Plasma levels of six inflammatory proteins (human epididymis protein 4 (HE4), matrix metalloproteinase (MMP) 1 and 3, cathepsin S, chitinase 3 like-1, cathepsin S, and B-cell activating factor (BAFF)) were quantified at baseline. Patients were followed for a total of 5 years (60 months), and major adverse cardiovascular events (MACEs, defined as the composite of myocardial infarction, cerebrovascular attack, and cardiovascular-related death) were recorded. A Cox proportional hazard model was created using biomarker levels, age, sex, hypertension, hypercholesterolemia, diabetes mellitus, smoking status, and coronary artery disease to determine whether the baseline levels of these proteins were associated with MACEs over 5 years. Results: HE4, MMP-3, BAFF, and cathepsin S levels were significantly elevated in AAA patients compared to controls (all p < 0.05). HE4/WFDC2, MMP-3, and Chitinase 3-like 1 were significantly linearly associated with AAA diameter at baseline. With every normalized unit increase in HE4/WFDC2, MMP-3, and Chitinase 3-like 1, there was an increase in abdominal aortic diameter by 0.154 (95% CI: 0.032–0.276, p = 0.013), 0.186 (95% CI: 0.064–0.309, p = 0.003), and 0.231 (0.110–0.353, p < 0.001) centimeters, respectively. Among patients with AAA, elevated HE4 was associated with higher risk of MACEs (adjusted HR 1.249; 95% CI: 1.057–1.476; p = 0.009). Patients with high baseline HE4 (≥9.338 ng/mL) had significantly lower freedom from MACEs at 5 years (76.7% vs. 84.8%, p = 0.022). Conclusions: HE4 may be a potential prognostic biomarker that can be used to risk stratify patients with AAA to better personalize treatment strategies to reduce adverse events. Full article

Increasing evidence underlines the role of B-cells in the development of hepatic fibrogenesis following viral infections and metabolic dysfunction, through different mechanisms depending on the etiology. Circulating biomarkers of B-cell activation—such as B-cell activating factor (BAFF), immunoglobulin G (IgG) subclasses, and free light chains (FLCs)—may be associated with different results between viral and metabolic hepatic fibrosis, supporting their use as diagnostic tools. We conducted a case-control study including 100 patients with liver fibrosis, 50/100 of metabolic etiology and 50/100 of viral etiology. A reference group of 30 healthy donors was included as control. Serum levels of BAFF were measured using ELISA, while IgG subclasses (IgG1, IgG2, IgG3, IgG4), κ-FLC, λ-FLC, and the κ/λ ratio were quantified by turbidimetric methods. In univariate analysis, κ-FLC, λ-FLC, and BAFF levels were significantly elevated in both patient groups, with the highest concentrations consistently observed in metabolic fibrosis. IgG2 was selectively increased in metabolic fibrosis, whereas IgG3 was specifically elevated in viral fibrosis. Multivariate analysis confirmed these findings, showing a clear clustering of the three groups and identifying increased BAFF and κ-FLC as key features of metabolic fibrosis, while elevated IgG3 emerged as the most distinctive marker of viral etiology. These results reveal distinct B-cell-related immunological signatures in metabolic and viral hepatic fibrosis supporting the role of BAFF, FLCs, and IgG subclasses as biomarkers of etiological differentiation, and provide novel insights into the immune mechanisms driving fibrosis progression, potentially contributing to the identification of new therapeutic targets. Full article

Objectives: The aim of this study was to find correlations between vitamin D deficiency and thyroid autoimmune pathology in a group of patients from Dobrogea, a non-endemic geographical area, with a high degree of sunshine. An important factor in maintaining immunological balance is the intake of an adequate level of vitamin D. Multiple studies have suggested that vitamin D deficiency is associated with a higher incidence of autoimmune diseases. Recent studies have analyzed the possible effect of this factor in promoting autoimmunity, as the serum level of BAFF often increases among patients with systemic autoimmune diseases. Methods: This study included 80 patients with autoimmune thyroid pathology from the Dobrogea area. The entire study group (n = 80) was divided according to the established diagnosis into two study groups: Group 1 included 62 patients with CAT (chronic autoimmune thyroiditis), and Group 2 included 18 patients with GD (Graves’ disease). Results: Vitamin D study average values of 25-OH-vitamin D found statistically significant differences between vitamin D values in the two groups (p = 0.018). Determination of BAFF (B-cell-activating factor) serum levels among patients with CAT and GD obtained a lower mean value of BAFF for the CAT group compared with the GD group. The evolution of BAFF serum level related to the serum levels of the antithyroid antibodies ATPO (antithyroidperoxidase) and ATG (antithyroglobulin) was also analyzed. In the patients with GD, BAFF was not correlated with the value of ATPO or ATG, but in the patients with CAT, a correlation was found between the value of BAFF and the level of ATG but not the ATPO level. Conclusions: This study analyzed BAFF serum levels in patients with CAT and GD. The results indicate that BAFF acts as a stimulatory factor of immunoglobulin production in autoimmune diseases. These results require clarifying the role and therapeutic benefits of supplementing vitamin D intake in patients with autoimmune diseases. Full article

Background: Chemoresistance is an existing challenge faced in the treatment of the hairy cell leukemia variant (HCL-v). Classical hairy cell leukemia (HCL-c) is very sensitive to the standard of care with purine nucleoside analogs (PNAs) cladribine (cDa) and pentostatin. However, almost half of these patients eventually become less sensitive to chemotherapy and relapse. HCL-variant (HCL-v) is a biologically distinct entity from HCL-c that is not sensitive to frontline PNA therapy, and this treatment is not recommended for these patients. To address these treatment challenges, we investigated the role of B-cell activating factor (BAFF) in promoting HCL-v cell chemoresistance. Methods: Flow cytometry and quantitative PCR were used to measure the levels of BAFF and its receptors. To determine BAFF activated pathways in HCL-c and HCL-v, the Bonna-12 HCL-c cell line or HCL-v patient-derived cancer cells were stimulated with recombinat BAFF and activation of common BAFF-activated pathways, including the nonclassical nuclear factor kappa B (NF-κB) pathway, the Extracellular Signal-Regulated Kinase (Erk) and phosphatidylinositol-3 (PI-3) kinase (PI3K)/AKT serine/threonine kinase (AKT) pathways were measured by western blotting. To test whether BAFF signaling promotes chemoresistance in HCL-v, we stimulated patient-derived HCL-v cells with BAFF and performed RNA sequencing. Lastly, to confirm the functional implications of BAFF signaling in HCL-v, we treated patient-derived HCL-v cells with exogenous BAFF before treatment with cladribine. Results: We found that HCL-v patient-derived cancer cells express receptors of BAFF at varying degrees and express relatively lower levels of membrane-bound BAFF ligand expression. BAFF stimulation of these cells resulted in substantial activation of the nonclassical NF-κB pathway, which is known to promote anti-apoptotic and pro-survival effects in B-cell cancers. Conversely, in the Bonna-12 cell line, we observed constitutive activation of the nonclassical NF-κB pathway. Through RNA sequencing, we found that BAFF upregulates a myriad of genes that are known to promote chemoresistance in various cancers, including IL1, CXCL1/2, CXCL5, CXCL8, TRAF3, and PTGS2. Lastly, we found that BAFF protects these cells from cladribine-induced cell death in vitro. Conclusions: We conclude that BAFF provides chemo-protection in HCL-v cells by activating nonclassical NF-κB signaling, which results in the upregulation of multiple pro-survival or anti-apoptotic genes. Our results highlight an important role of BAFF in HCL-v resistance to chemotherapy and suggest that the BAFF blockade may enhance the chemosensitivity to PNAs in drug-resistant HCL-v patients. Full article

Current therapies for Graves’ disease (GD) primarily aim to manage hyperthyroidism through synthetic antithyroid drugs, radioiodine, or surgery. However, these approaches are often limited by their incomplete efficacy and the risk of inducing hypothyroidism. The latest advances in understanding the autoimmune mechanisms driving GD have paved the way for novel therapies targeting the thyrotropin receptor (TSH-R) or immune pathways. Overall, key targets include cluster of differentiation 20 (CD20), cluster of differentiation 40 (CD40), protein tyrosine phosphatase non-receptor type 22 (PTPN22), cytotoxic T lymphocyte antigen-4 (CTLA-4), B cell-activating factor (BAFF), and the Fc receptor-like protein 3 (FcRL3). Recent preclinical studies and clinical trials testing targeted therapies have shown promising results in terms of efficacy and safety. Here, we present a narrative review of the literature on emerging therapeutic approaches for GD that are currently under investigation. Full article

This study investigated the diagnostic, prognostic, and therapeutic significance of Fc receptor-like 1 (FCRL1) and B-cell activating factor (BAFF) mRNA expression in Egyptian patients with diffuse large B-cell lymphoma (DLBCL) undergoing the standard R-CHOP regimen (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) using quantitative real-time PCR (RT-qPCR). The results demonstrated that FCRL1 and BAFF mRNA expression were significantly elevated in DLBCL patients compared to healthy controls. A strong positive correlation existed between BAFF and FCRL1 expression levels. Diagnostic performance assessed through combined ROC curve analysis revealed that BAFF, FCRL1, and lactate dehydrogenase (LDH) achieved perfect diagnostic accuracy (AUC = 1.0), demonstrating 100% sensitivity, specificity, and predictive values. Further prognostic analysis using COX regression identified elevated FCRL1 expression as the most significant predictor of poor clinical outcomes. Kaplan–Meier survival analysis reinforced this finding, with high FCRL1 expression showing significant associations with reduced overall survival (OS, p = 0.031) and progression-free survival (PFS, p = 0.038). The study underscores the potential utility of BAFF and FCRL1 mRNA as diagnostic markers for DLBCL, with FCRL1 emerging as a promising prognostic marker and potential therapeutic target enabling more tailored treatment approaches for DLBCL, the most common type of B-cell non-Hodgkin lymphoma, and patients receiving R-CHOP therapy. Full article

Background/Objectives: Understanding the behavior of B cells during infection and vaccination is important for determining protective humoral immunity. We evaluated the profile of humoral immunity and B cell pool in individuals who were acutely infected with SARS-CoV-2, recovered from COVID-19, or received two doses of the AZD1222 vaccine. Methods: Peripheral blood mononuclear cells (PBMCs) from these individuals were subjected to in vitro stimulation to promote the differentiation of B cells into antibody-secreting cells (ASCs), and the ELISpot evaluated the abundance of pan and SARS-CoV-2 Spike S1-reactive IgG+ ASC. Stimulated PBMCs were characterized using flow cytometry. Culture supernatants were assessed for soluble B-cell-activating factors. The IgA and IgG for the S1 were evaluated through ELISA. Results: The recovered individuals displayed a robust S1 ASC compared to acute and vaccinated individuals. Although the frequency of total B cells or B cell subsets did not vary among the groups, plasmablast cells were increased in naïve and double-negative B cells in the acute, recovered, and vaccinated individuals. Similar IgA and IgG production appeared to be present in the acute and recovered individuals. During vaccination, more IgG is produced than IgA. In acute patients, BAFF levels were positively correlated with total B cells and IgG+ plasmablast cells but negatively correlated with IgA+ plasmablast cells. Conclusions: Vaccination and natural infection with COVID-19 induce a differential profile and functionality of B cells. We suggest that new vaccines against COVID-19 incorporate molecular adjuvants that regulate B lymphocyte functionality and consider the beneficial aspects of the IgA response in addition to IgG. Full article

Autoimmune diseases represent a severe personal and healthcare problem that seeks novel therapeutic solutions. Mesenchymal stem cells (MSCs) are multipotent cells with interesting cell biology and promising therapeutic potential. The immunoregulatory effects of secretory factors produced by umbilical cord mesenchymal stem cells (UC-MSCs) were assessed on B lymphocytes from 17 patients with systemic lupus erythematosus (SLE), as defined by the 2019 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for SLE, and 10 healthy volunteers (HVs). Peripheral blood mononuclear cells (PBMCs) from patients and HVs were cultured in a UC-MSC-conditioned medium (UC-MSCcm) and a control medium. Flow cytometry was used to detect the surface expression of CD80, CD86, BR3, CD40, PD-1, and HLA-DR on CD19+ B cells and assess the percentage of B cells in early and late apoptosis. An enzyme-linked immunosorbent assay (ELISA) quantified the production of BAFF, IDO, and PGE2 in PBMCs and UC-MSCs. Under UC-MSCcm influence, the percentage and mean fluorescence intensity (MFI) of CD19+BR3+ cells were reduced in both SLE patients and HVs. Regarding the effects of the MSC secretome on B cells in lupus patients, we observed a decrease in CD40 MFI and a reduced percentage of CD19+PD-1+ and CD19+HLA-DR+ cells. In contrast, in the B cells of healthy participants, we found an increased percentage of CD19+CD80+ cells and decreased CD80 MFI, along with a decrease in CD40 MFI and the percentage of CD19+PD-1+ cells. The UC-MSCcm had a minimal effect on B-cell apoptosis. The incubation of patients’ PBMCs with the UC-MSCcm increased PGE2 levels compared to the control medium. This study provides new insights into the impact of the MSC secretome on the key molecules involved in B-cell activation and antigen presentation and survival, potentially guiding the development of future SLE treatments. Full article

IgA nephropathy (IgAN) is characterized by immune-mediated glomerulonephritis, with the accumulation of galactose-deficient IgA1 (Gd-IgA1) in the glomeruli and increased levels of circulating Gd-IgA1 and Gd-IgA1-containing immune complexes. An incomplete understanding of the underlying mechanisms and differences in clinical and pathological features between individuals and ethnicities has contributed to the lack of established treatments for IgAN. A tumor necrosis factor (TNF) family member, a proliferation-inducing ligand (APRIL), is a crucial cytokine essential for the generation and survival of plasma cells. Recent studies demonstrated that APRIL is a pivotal mediator in the production of Gd-IgA1 in IgAN. As our understanding of the autoimmune pathogenesis underlying IgAN has improved, various pharmacological therapeutic targets, including APRIL antagonists, have emerged. Preliminary results showed that APRIL-targeting agents effectively reduced proteinuria and Gd-IgA1 levels without significantly increasing adverse events, indicating their potential as novel therapeutic agents for IgAN. In the present review, we discuss the current understanding of the role of APRIL in the pathogenesis of IgAN and novel therapeutic strategies focusing on APRIL-targeting agents for IgAN. APRIL inhibitors may offer new hope to patients with IgAN. Full article

Introduction: Systemic lupus erythematosus (SLE) is a multifaceted autoimmune disorder characterized by significant autoantibodies, particularly targeting nuclear antigens. SLE pathogenesis involves genetic, environmental, and hormonal factors. The disease course includes flares and remission and involves various organs. Recent therapeutic progresses, including biologics, have improved management and prognosis, though the long-term impact of novel therapies remains to be determined. Biologics in SLE: Rituximab, the earliest B-cell-oriented biologic, binds CD20 and depletes CD20+ B cells, leading to remission in some SLE patients. Belimumab is a B-cell-activating factor (BAFF) inhibitor with a recent additional indication for lupus nephritis. The CALIBRATE and BLISS-BELIEVE studies investigated combinations of these drugs with conventional therapies, showing varied efficacy. Ocrelizumab and obinutuzumab, newer CD20-oriented SLE therapies, together with ofatumumab and veltuzumab, are also promising. The latest trials highlight their efficacy and safety. Anifrolumab, targeting type-I interferon receptors, was evaluated in the TULIP 1/2 trials. The ongoing TULIP LTE trial supports the long-term safety and efficacy of anifrolumab. Additionally, the IRIS Phase III trial is exploring anifrolumab for lupus nephritis, showing favorable renal responses. Tocilizumab and secukinumab are being assessed for SLE, with mixed outcomes. Several biologics targeting the C5 complement protein, together with immunomodulators and immunotherapeutics, are also under investigation for potential benefits in SLE. Discussion: Biologics in SLE target specific immune components, aiming to improve disease control and reduce the side effects of conventional therapy. However, trial outcomes vary due to factors like inclusion criteria and trial design. Conclusions: Biotechnology progress enables targeted biologic therapies for SLE, reducing disease activity and improving patients’ quality of life. Full article

A T-cell-independent (TI) pathway activated by microbiota results in the generation of low-affinity homeostatic IgA with a critical role in intestinal homeostasis. Moderate aerobic exercise (MAE) provides a beneficial impact on intestinal immunity, but the action of MAE on TI-IgA generation under senescence conditions is unknown. This study aimed to determine the effects of long-term MAE on TI-IgA production in young (3 month old) BALB/c mice exercised until adulthood (6 months) or aging (24 months). Lamina propria (LP) from the small intestine was obtained to determine B cell and plasma cell sub-populations by flow cytometry and molecular factors related to class switch recombination [Thymic Stromal Lymphopoietin (TSLP), A Proliferation-Inducing Ligand (APRIL), B Cell Activating Factor (BAFF), inducible nitric oxide synthase (iNOS), and retinal dehydrogenase (RDH)] and the synthesis of IgA [α-chain, interleukin (IL)-6, IL-21, and Growth Factor-β (TGF-β)]; and epithelial cells evaluated IgA transitosis [polymeric immunoglobulin receptor (pIgR), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IL-4] by the RT-qPCR technique. The results were compared with data obtained from sedentary age-matched mice. Statistical analysis was computed with ANOVA, and p < 0.05 was considered to be a statistically significant difference. Under senescence conditions, MAE promoted the B cell and IgA+ B cells and APRIL, which may improve the intestinal response and ameliorate the inflammatory environment associated presumably with the downmodulation of pro-inflammatory mediators involved in the upmodulation of pIgR expression. Data suggested that MAE improved IgA and downmodulate the cytokine pro-inflammatory expression favoring homeostatic conditions in aging. Full article

Although rituximab is not specifically approved for the treatment of warm autoimmune hemolytic anemia (WAIHA), the First International Consensus Group recommends considering its use as part of the initial therapy for patients with severe disease and as a second-line therapy for primary WAIHA. Some patients do not respond to rituximab, and relapses are common. These relapses are associated with elevated B-cell-activating factor (BAFF) levels and the presence of quiescent long-lived plasma cells (LLPCs) in the spleen. A new group of immunomodulatory drugs, B-cell-activating factor inhibitors (BAFF-i), demonstrated efficacy in multiple autoimmune diseases and have the potential to improve WAIHA treatment outcomes by targeting B-cells and LLPCs. This article reviews the role of BAFF in autoimmune disorders and the currently available literature on the use of BAFF-directed therapies in various immunologic disorders, including WAIHA. Collectively, the clinical data thus far shows robust potential for targeting BAFF in WAIHA therapy. Full article