CD20-Mimotope Peptide Active Immunotherapy in Systemic Lupus Erythematosus and a Reappraisal of Vaccination Strategies in Rheumatic Diseases

Immune cell aberrations in Systemic Lupus Erythematosus: navigating the targeted therapies toward precision management

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by multilayered dysregulation of immune cell homeostasis, spanning B cell effector dysfunction, T follicular helper (Tfh) cell hyperactivity, and plasmacytoid dendritic cell (pDC) tolerance breakdown. Advances in high-parameter immunophenotyping, single-cell multiomics profiling, and spatial multiomics have redefined SLE pathogenesis, revealing stage-specific immune network perturbations. These discoveries have propelled mechanism-driven therapeutic strategies, including CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy for B cell depletion, disruption of T-B cell synaptic signaling (CD40L inhibitors), and restoration of pDC tolerance (anti-BDCA2 antibodies). While patient heterogeneity poses challenges for universal therapeutic efficacy, emerging strategies integrating molecular endotyping and cellular biomarkers hold promise for overcoming these limitations. By aligning targeted therapies with the immunophenotypic signatures of individual patients, precision medicine approaches are expected to optimize treatment efficacy, minimize off-target effects, and ultimately enhance long-term clinical outcomes in SLE. This review synthesizes current insights into how immune cell perturbations contribute to SLE pathogenesis, modulate disease flares, and determine therapeutic refractoriness, with a critical synthesis of recent clinical trial outcomes.

Bischoff D, S Singh S, H. Hahn B. Peptide-based immunotherapy in lupus: Where are we now?

In autoimmune rheumatic diseases, immune hyperactivity and chronic inflammation associate with immune dysregulation and the breakdown of immune self-tolerance. A continued, unresolved imbalance between effector and regulatory immune responses further exacerbates inflammation that ultimately causes tissue and organ damage. Many treatment modalities have been developed to restore the immune tolerance and immmunoregulatory balance in autoimmune rheumatic diseases, including the use of peptide-based therapeutics or the use of nanoparticles-based nanotechnology. This review summarizes the state-of-the-art therapeutic use of peptide-based therapies in autoimmune rheumatic diseases, with a specific focus on lupus.

A novel BAFF antagonist, BAFF-Trap, effectively alleviates the disease progression of systemic lupus erythematosus in MRL/lpr mice

Abnormal B cells, which produce antibodies against self-antigens, play a key role in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). B-cell activating factor (BAFF) is closely associated with abnormal B cells and participates in B cell-mediated autoimmune diseases; thus, neutralizing BAFF is an effective method for treating these diseases. Our group designed a novel fusion protein, BAFF-Trap, that contains the BAFF-binding domains of two BAFF receptors (TACI and BAFF-R) and the Fc domain of human IgG1. In this study, we showed that BAFF-Trap significantly decreased the autoantibody levels, BAFF concentrations and B cells numbers in MRL/lpr mice. BAFF-Trap suppressed the expression of pro-inflammatory cytokines in the kidney and decreased the frequencies of T cell subsets and dendritic cells. Furthermore, BAFF-Trap reduced proteinuria and IgG deposition, relieved glomerular damage in the kidney, and markedly improved the survival rate of mice. These results indicated that BAFF-Trap may be a potential drug for the treatment of SLE.

Peptide-Based Vaccination Therapy for Rheumatic Diseases

Rheumatic diseases are extremely heterogeneous diseases with substantial risks of morbidity and mortality, and there is a pressing need in developing more safe and cost-effective treatment strategies. Peptide-based vaccination is a highly desirable strategy in treating noninfection diseases, such as cancer and autoimmune diseases, and has gained increasing attentions. This review is aimed at providing a brief overview of the recent advances in peptide-based vaccination therapy for rheumatic diseases. Tremendous efforts have been made to develop effective peptide-based vaccinations against rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), while studies in other rheumatic diseases are still limited. Peptide-based active vaccination against pathogenic cytokines such as TNF-α and interferon-α (IFN-α) is shown to be promising in treating RA or SLE. Moreover, peptide-based tolerogenic vaccinations also have encouraging results in treating RA or SLE. However, most studies available now have been mainly based on animal models, while evidence from clinical studies is still lacking. The translation of these advances from experimental studies into clinical therapy remains impeded by some obstacles such as species difference in immunity, disease heterogeneity, and lack of safe delivery carriers or adjuvants. Nevertheless, advances in high-throughput technology, bioinformatics, and nanotechnology may help overcome these impediments and facilitate the successful development of peptide-based vaccination therapy for rheumatic diseases.

CD20-Mimotope Peptides: A Model to Define the Molecular Basis of Epitope Spreading

Antigen-mimicking peptide (mimotope)-based vaccines are one of the most promising forms of active-immunotherapy. The main drawback of this approach is that it induces antibodies that react poorly with the nominal antigen. The aim of this study was to investigate the molecular basis underlying the weak antibody response induced against the naïve protein after peptide vaccination. For this purpose, we analyzed the fine specificity of monoclonal antibodies (mAb) elicited with a 13-mer linear peptide, complementary to theantigen-combining site of the anti-CD20 mAb, Rituximab, in BALB/c mice. Anti-peptide mAb competed with Rituximab for peptide binding. Even so, they recognized a different antigenic motif from the one recognized by Rituximab. This explains their lack of reactivity with membrane (naïve) CD20. These data indicate that even on a short peptide the immunogenic and antigenic motifs may be different. These findings highlight an additional mechanism for epitope spreading and should be taken into account when designing peptides for vaccine purposes.