Publications

Lupus nephritis (LN) is common in people with systemic lupus erythematosus (SLE) and advances, almost invariably, to end-stage renal disease (ESRD). In this issue of the JCI, Abraham, Durkee, et al. presented a large-scale immune cell landscape of kidney biopsies from patients with LN by combining multiplexed confocal microscopy imaging with customized computer vision and quantification. The presence of diverse CD4- T cells in small neighborhoods, but not of B cells or CD4+ T cells in large neighborhoods, is linked to the development of ESRD. Unexpectedly, B cells in the kidney heralded a good prognosis. The precise location of different types of immune cells allows inference on possible interactions between different immune cells and also between immune and kidney-resident cells. The data have important implications on the development of prognostic tools and effective targeted therapies in patients with LN.

T-cells are critically involved in the pathogenesis of systemic lupus erythematosus. Although treatment with the anti-CD3 antibody has been reported to be effective in several autoimmune disease animal models including lupus, the immunosuppressive mechanisms remain obscure because of its pleiotropic in vivo kinetics. In this study, a conventional anti-CD3 (2C11C) and a non-mitogenic anti-CD3 with a manipulated Fc region (2C11S) were compared to elucidate the underlying mechanism of action. The efficacy and safety of 2C11S in vivo were demonstrated by sustained TCR reduction for a longer period as compared to 2C11C and no induction of cytokine release or T-cell depletion. Anti-CD3s were administered to NZB/W F1 (BWF1) mice at different time points for individual periods. The short-term treatment with 2C11S in the early phase of lupus suppressed the autoantibody associated with the reduction of germinal center B-cells. Treatment in the late phase attenuated lupus nephritis without affecting autoantibodies or differentiation of effector T-cells. The effect of reduced TCR in the development of autoimmunity was examined by CD3zeta heterozygous-deficient mice, in which T-cells had reduced TCR intensity but showed normal TCR signaling response. Autoantibody and lupus nephritis were attenuated significantly in CD3zeta heterozygous-deficient lupus-prone mice. Collectively, the reduction of surface TCR by non-mitogenic anti-CD3 could sufficiently suppress the development of lupus.

We had shown previously that the protein phosphatase 2A regulatory subunit PPP2R2D suppresses IL-2 production, and PPP2R2D deficiency in T cells potentiates the suppressive function of regulatory T (Treg) cells and alleviates imiquimod-induced lupus-like pathology. In this study, in a melanoma xenograft model, we noted that the tumor grew in larger sizes in mice lacking PPP2R2D in T cells (Lck(Cre)R2D(fl/fl)) compared with wild type (R2D(fl/fl)) mice. The numbers of intratumoral T cells in Lck(Cre)R2D(fl/fl) mice were reduced compared with R2D(fl/fl) mice, and they expressed a PD-1(+)CD3(+)CD44(+) exhaustion phenotype. In vitro experiments confirmed that the chromatin of exhaustion markers PD-1, LAG3, TIM3, and CTLA4 remained open in Lck(Cre)R2D(fl/fl) CD4 T conventional compared with R2D(fl/fl) T conventional cells. Moreover, the percentage of Treg cells (CD3(+)CD4(+)Foxp3(+)CD25(hi)) was significantly increased in the xenografted tumor of Lck(Cre)R2D(fl/fl) mice compared with R2D(fl/fl) mice probably because of the increase in the percentage of IL-2-producing Lck(Cre)R2D(fl/fl) T cells. Moreover, using adoptive T cell transfer in mice xenografted with melanoma, we demonstrated that PPP2R2D deficiency in T cells enhanced the inhibitory effect of Treg cells in antitumor immunity. At the translational level, analysis of publicly available data from 418 patients with melanoma revealed that PPP2R2D expression levels correlated positively with tumor-infiltration level of CD4 and CD8 T cells. The data demonstrate that PPP2R2D is a negative regulator of immune checkpoint receptors, and its absence exacerbates effector T cell exhaustion and promotes Treg cell expansion. We conclude that PPP2R2D protects against melanoma growth, and PPP2R2D-promoting regimens can have therapeutic value in patients with melanoma.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by defective regulatory T (T(reg)) cells. Here, we demonstrate that a T cell-specific deletion of calcium/calmodulin-dependent protein kinase 4 (CaMK4) improves disease in B6.lpr lupus-prone mice and expands T(reg) cells. Mechanistically, CaMK4 phosphorylates the glycolysis rate-limiting enzyme 6-phosphofructokinase, platelet type (PFKP) and promotes aerobic glycolysis, while its end product fructose-1,6-biphosphate suppresses oxidative metabolism. In T(reg) cells, a CRISPR-Cas9-enabled Pfkp deletion recapitulated the metabolism of Camk4(-/-) T(reg) cells and improved their function and stability in vitro and in vivo. In SLE CD4(+) T cells, PFKP enzymatic activity correlated with SLE disease activity and pharmacologic inhibition of CaMK4-normalized PFKP activity, leading to enhanced T(reg) cell function. In conclusion, we provide molecular insights in the defective metabolism and function of T(reg) cells in SLE and identify PFKP as a target to fine-tune T(reg) cell metabolism and thereby restore their function.

The complement system is involved in the origin of autoimmunity and systemic lupus erythematosus. Both genetic deficiency of complement components and excessive activation are involved in primary and secondary renal diseases, including lupus nephritis. Among the pathways, the classical pathway has long been accepted as the main pathway of complement activation in systemic lupus erythematosus. However, more recent studies have shown the contribution of factors B and D which implies the involvement of the alternative pathway. While there is evidence on the role of the lectin pathway in systemic lupus erythematosus, it is yet to be demonstrated whether this pathway is protective or harmful in lupus nephritis. Complement is being explored for the development of disease biomarkers and therapeutic targeting. In the current review we discuss the involvement of complement in lupus nephritis.

To explore bias in lupus erythematosus (LE) randomized clinical trials (RCTs) and to help the development of benchmarks for future trials and management. We searched systematically three databases and three registries to summarize the interventional randomized clinical trials (RCTs) and identify factors associated with participant loss. Trials which examined pharmacological interventions with control group were included and a meta-analysis was carried out by using fixed and random effects models to calculate risk ratio of participant loss in the intervention and control groups. A total of 481 trials with 68,582 participants met our inclusion criteria, organ specific interventional studies along with trials that address quality of life attributes and geopolitical disparities are missing or lagging behind. 90 trials were involved in the meta-analyses, the withdrawal ratio between intervention and control groups was distinctly influenced by national income of the trial-conducted country. In high income countries, the withdrawal ratio was relatively constant, while for trials conducted in low and middle income countries, the results were altered by trial registration, year of start, number of centers, number of participants, and primary outcome identification. Moreover, the comparability of participants was also worrying, trial location and registration status altered basal participant adherence. Our study reveals the unexpectedly huge heterogeneity brought by national income and trial registration in lupus RCTs worldwide. To maintain the fundamental repeatability and referenceability of LE RCTs, rigorously designed single-country trials with diverse inclusion criteria are needed.

OBJECTIVE: To evaluate the long-term efficacy and safety of ustekinumab through 2 years in patients with active systemic lupus erythematosus (SLE). METHODS: This was a placebo-controlled (week 24), phase II study in 102 patients with seropositive active SLE. Patients were randomized to ustekinumab (approximately 6 mg/kg single intravenous infusion, then subcutaneous [SC] injections of 90 mg every 8 weeks) or placebo, added to background therapy. Placebo patients initiated ustekinumab (90 mg SC every 8 weeks) at week 24. Patients could enter an optional open-label study extension after week 40 (final ustekinumab administration at week 104). Efficacy assessments included Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), SLEDAI-2K Responder Index-4 (SRI-4), physician global assessment (PGA), and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Observed data are reported for the extension period. The final efficacy assessment was at week 112; safety was monitored through week 120. RESULTS: In this subset of patients who entered the study extension, 24 in the ustekinumab group and 14 in the placebo crossover group completed study treatment. At week 112, 79% and 92%, respectively, had an SRI-4 response; 92% in both groups had >/= 4-point improvement from baseline in SLEDAI-2K score; 79% and 93%, respectively, had >/= 30% improvement from baseline in PGA; 86% and 91%, respectively, had >/= 50% improvement in active joint (pain and inflammation) count; and 79% and 100%, respectively, had >/= 50% improvement in CLASI Activity Score. No deaths, malignancies, opportunistic infections, or tuberculosis cases occurred. Safety events were consistent with the known ustekinumab safety profile. CONCLUSION: Of the 46 patients who entered the voluntary extension of this phase II study, clinical benefit in global and organ-specific SLE activity measures was observed with ustekinumab through 2 years with no new or unexpected safety findings. [ClinicalTrials.gov: NCT02349061].

Autoimmune diseases are characterized by dysregulation and aberrant activation of cells in the immune system. Therefore, restoration of the immune balance represents a promising therapeutic target in autoimmune diseases. Interleukin-2 (IL-2) can promote the expansion and differentiation of different immune cell subsets dose-dependently. At high doses, IL-2 can promote the differentiation and expansion of effector and memory T cells, whereas at low doses, IL-2 can promote the differentiation, survival, and function of regulatory T (T(reg)) cells, a CD4(+) T cell subset that is essential for the maintenance of immune homeostasis and immune tolerance. Therefore, IL-2 exerts immunostimulatory and immunosuppressive effects in autoimmune diseases. The immunoregulatory role of low-dose IL-2 has sparked excitement for the therapeutic exploration of modulating the IL-2-T(reg) axis in the context of autoimmune diseases. In this review, we discuss recent advances in the therapeutic potential of IL-2 or IL-2-derived molecules in the treatment of autoimmune diseases.