Novel Treatments in Lupus

Systemic lupus erythematosus: an expert insight into emerging therapy agents in preclinical and early clinical development

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic disease that is potentially fatal. There is no cure for SLE and the medications used are associated with toxic side effects. In the era of revolutionary emerging novel biologic agents, the design and investigation of targeted therapy for these patients is necessary. Novel therapies under investigation in phase II-III clinical trials showed promising results. Therapies can target various pathways involved in SLE including cytokines, signal transduction inhibitors, B-cell depletion and interference with co-stimulation. Of interest is the proof of concept of sequential therapy.

AREAS COVERED

We performed an extensive literature search via PubMed, Medline, Elsevier Science and Springer Link databases between the years 2014-2020 using the following terms: SLE, novel treatments. We have reviewed 232 articles and selected those articles that (i) focus on phase II-III emerging therapies and (ii) offer new findings from existing therapies, which reveal breakthrough concepts in SLE treatment.

EXPERT OPINION

It is still difficult to crack the puzzle of a successful SLE treatment approach. New strategies with potential may encompass the targeting of more than one protein. Another way forward is to identify each SLE patient and personalize therapy by clinical manifestations, disease activity, serology and activated protein.

Signaling Lymphocytic Activation Molecule Family Member 1 Engagement Inhibits T Cell-B Cell Interaction and Diminishes Interleukin-6 Production and Plasmablast Differentiation in Systemic Lupus Erythematosus

OBJECTIVE

Signaling lymphocytic activation molecule family member 1 (SLAMF1) homophilic interactions promote immunoglobulin production and T cell-B cell cross-talk. SLAMF1 is overexpressed on T and B cells in patients with systemic lupus erythematosus (SLE). This study was undertaken to determine the role of SLAMF1 monoclonal antibody (mAb) in modulating T cell-B cell interaction and B cell activation.

METHODS

Anti-IgM-prestimulated naive or total B cells from either healthy donors or patients with SLE were cocultured with autologous T cells under CD3/CD28 stimulation, in the presence or absence of the SLAMF1 mAb. Naive B cells were stimulated with anti-IgM and CD40L in the presence of the SLAMF1 antibody. Cytokine production by CD4+ T cells and B cells was examined by flow cytometry and/or quantitative polymerase chain reaction. Plasmablast formation and T cell and B cell conjugates were assessed by flow cytometry. IgG and antinuclear antibody production was determined by enzyme-linked immunosorbent assay.

RESULTS

SLAMF1 ligation in a human peripheral blood T cell-B cell culture system reduced the following in both healthy controls and patients with SLE: conjugate formation, interleukin-6 (IL-6) production by B cells, IL-21 and IL-17A production by T cells, and Ig and autoantibody production. Whereas the SLAMF1 mAb directly affected the function of isolated peripheral B cells by decreasing IL-6 and Ig production in vitro, it did not affect cytokine production by isolated T cells stimulated in vitro.

CONCLUSION

The SLAMF1 antibody inhibits T cell-B cell interaction and suppresses B cell cytokine production and differentiation, thereby acting as a potential therapeutic tool in the treatment of patients with SLE.

Targeting Regulatory T Cells to Treat Patients With Systemic Lupus Erythematosus

Regulatory T cells (Tregs) are central in integration and maintenance of immune homeostasis. Since breakdown of self-tolerance is a major culprit in the pathogenesis of systemic lupus erythematosus (SLE), restoration of the immune tolerance through the manipulation of Tregs can be exploited to treat patients with SLE. New information has revealed that Tregs besides their role in suppressing the immune response are important in tissue protection and regeneration. Expansion of Tregs with low-dose IL-2 represents an approach to control the autoimmune response. Moreover, control of Treg metabolism can be exploited to restore or improve their function. Here, we summarize the function and diversity of Tregs and recent strategies to improve their function in patients with SLE.