POS0135 DOWNREGULATION OF miR-885-5p AS A KEY EFFECTOR IN CUTANEOUS LUPUS ERYTHEMATOSUS PATHOGENESIS

Background

Skin involvement is common in systemic lupus erythematosus (SLE), with up to 70% of patients developing skin lesions at some point during the course of their disease. Moreover, cutaneous lesions are the first sign of systemic disease in 20% of SLE patients [1]. Skin requires a regulated and undisrupted miRNA profile for a correct development and function. Studies show that miRNAs play a pathogenic role in autoimmune skin diseases such as Psoriasis [2]. Understanding of the role of deregulated miRNAs in CLE may enhance our knowledge about CLE pathogenesis which is currently not understood.

Objectives

Identify differentially expressed miRNAs in skin lesions to determine their role in CLE pathogenesis.

Methods

Paired skin biopsies from CLE lesional (n=20) and non-lesional skin (n=20) were obtained. MiRNA microarray screening was performed using TaqMan MicroRNA Array. Validation was performed in a new cohort of FFPE skin samples by qRT-PCR (n=20). In situ hybridization was performed to identify the skin cell type involved in selected miRNAs. Next, in vitro experiments using primary skin and immune cells were performed in order to discover their role in CLE pathogenesis. A microarray screening and luciferase assay were performed to find miR-885-5p altered gene expression, molecular pathways and target genes.

Results

MiR-885-5p was found downregulated in CLE lesional skin (-4.45 fold, pvalue<0,01, respectively). Results were confirmed in a validation cohort. In situ hybridization revealed miR-885-5p was located in the epidermal keratinocytes in CLE non-lesional skin. Healthy keratinocytes presented an increased miR-885-5p expression compared with other relevant cell types such as fibroblasts (p<0.001) or PBMCs (p<0.001). Moreover stimulation with IFNα and UVB promoted a marked long-lasting downregulation of miR-885-5p (IFNα, 24h -67 fold (p<0.001); UVB, 24h -70 fold (p<0.001)).

Gene microarray of anti-miR-885-5p keratinocytes showed that the unique gene that was upregulated in all anti-miR-885-5p conditions was PSMB5. In vitro experiments demonstrated that PSMB5 is a direct target of miR-885-5p (74% of reduction p<0.001) and it is involved in epidermal inflammation by enhancing NFKB and inflammatory cytokines IL-1β, TNFα and CXCL8. In addition, we observed immune recruitment in UVB stimulated anti-miR885-5p keratinocytes and we found that this immune migration is mediated via miR-885-5p direct binding of TRAF1 and subsequent chemokine CCL5, CCL20, CXCL8 and S100A7 secretion.

Conclusion

Our findings demonstrate that CLE lesions present a downregulation of miR-885-5p that is strongly implicated in CLE pathogenesis. Moreover, miRNA applicability as therapeutics makes the discovered miRNAs promising candidates for novel therapy in CLE, as there is a need to develop new therapies for refractory cases and to avoid current treatment significant side effects.

References

[1]Okon LG, Werth VP. Cutaneous lupus erythematosus: diagnosis and treatment. Best Pract Res Clin Rheumatol. 2013; 27(3):391-404.

[2]Sonkoly E et al. MicroRNAs: novel regulators involved in the pathogenesis of psoriasis? PLoS One. 2007. 11;2(7):e610.

Disclosure of Interests

None declared

POS0463 REENGINEERING CHIMERIC ANTIGEN RECEPTOR T CELLS FOR TARGETED THERAPY OF LUPUS NEPHRITIS

Background

Although the pathogenesis of lupus nephritis (NL) is not completely clear, it is known that the production of anti-dsDNA or anti-C1q antibodies is related to its activity [1]. Despite treatment, approximately 30-40% of patients continue to present a significant number of renal outbreaks [2]. Therefore, there is a growing interest in the development of more specific drugs. As B cells play a central role in the pathogenesis of SLE, the therapy CAR-T cells has been studied reporting good results for the prevention and also for as treatment in murine lupus models [3,4]. Recently, a new selective immunotherapy for autoimmune diseases has been demonstrated by modifying the T cells with a chimeric autoantigen receptor (CAAR) [5]. This novel therapeutic approach could be beneficial in NL with the aim of depleting only anti-DNA producing B cells. In this way, the benefits of anti-CD20 biologics would be obtained, but it would be much more specific, personalized and, surely, effective since only the self-reactive B cells would be destroyed.

Objectives

To study CAAR-Tcell anti-dsDNA and anti-C1q therapy in NL through in vitro experiments (primary cells and kidney organoids).

Methods

Synthesis of 6 CAAR anti-dDNA that will be transfected in the primary T cells extracted from patients with NL and healthy controls (N = 10 per group). Through in vitro experiments their ability to lyse the B cells that produce anti-dsDNA or anti-C1q will be evaluated. The two CAAR-Tcell models that is most effective will be evaluated using kidney organoid models obtained from human samples.

Results

We engineered six human T cells models to express a chimeric autoantibody receptor (CAAR), consisting lupus nephritis autoantigen. As antigens for anti-DNA produced B cells, we designed Heparanase1/2, Histone1 and alpha actinin 1/2 CAAR-Tcells. For anti-C1q produced B cells, we used C1q protein fused to CD19-CD3 signaling domains. The CAAR-Tcells models that exhibited specify cytotoxicity in vitro againts B cells producing anti-dDNA were Heparanase2 and alpha actinin1 CAAR-Tcells (selectivity of 75% vs 45%). C1q CAAR-T cells also presented specificy cytotoxicity for anti-C1q B cells (selectivity of 80%). In vivo imaging assay reveals that C1q or Heparanase2 CAAR-Tcells depleted completly B cells at 48 hours (ratio 1:10, Bcells:CAAR T-cells). We developed 3D in vitro organoid culture using human kidney organoid and B cells from lupus nephritis patients. We evaluated Heparanase2 and C1q CAAR-Tcells using them and we demostrated that C1q CAAR-Tcells could resolved better local kidney inflammation (reduction of IL6, TNF and INF cytokines levels).

Conclusion

Taken together, these results show that C1q CAAR-Tcells could be an effective and selective immune therapy for treatment of lupus nephritis. Currently, we are evaluated this therapy using NZWB/F1 murine models.

References

[1]Rekvig OP, Thiyagarajan D, Pedersen HL, Horvei KD, Seredkina N. Future Perspectives on Pathogenesis of Lupus Nephritis: Facts, Problems, and Potential Causal Therapy Modalities. Am J Pathol. 2016;186:2772-2782

[2]Liu Z, Davidson A. Taming lupus-a new understanding of pathogenesis is leading to clinical advances. Nat Med 2012;18:871–82.

[3]Kansal R et al. Sustained B cell depletion by CD19-targeted CAR T cells is a highly effective treatment for murine lupus. Sci Transl Med. 2019; 11:eaav1648.

[4]Jin X et al. Therapeutic efficacy of anti-CD19 CAR-T cells in a mouse model of systemic lupus erythematosus. Cell Mol Immunol. 2021;18:1896-1903.

[5]Christoph T et al. Reengineering chimeric antigen receptor T cells for targeted therapy of autoimmune disease. Science. 2016; 353:179-84.

Acknowledgements

I have acknowledgement Instituto de Salud Carlos III for their kind financial support (grant PI18/01917)

Disclosure of Interests

None declared.

Voltage-dependent potassium channels Kv1.3 and Kv1.5 in human cancer

Membrane ion channels participate in cancerous processes such as proliferation, migration and invasion, which contribute to metastasis. Increasing evidence indicates that voltage-dependent K(+) (Kv) channels are involved in the proliferation of many types of cells, including tumor cells. Kv channels have generated immense interest as a promising tool for developing new anti-tumor therapies. Therefore, the identification of potential biomarkers and therapeutic targets in specific cancers is an important prerequisite for the treatment. Since Kv1.3 and Kv1.5 are involved in the proliferation of many mammalian cells, we aimed to study the expression of Kv1.3 and Kv1.5 in a plethora of human cancers. Thus, tissues from breast, stomach, kidney, bladder, lung, skin, colon, ovary, pancreas, brain, lymph node, skeletal muscle and some of their malignant counterparts have been analyzed. Whereas Kv1.3 expression was either decreased or did not change in most tumors, Kv1.5 was overexpressed. However, the presence of Kv1.3 was mostly associated with inflammatory lymphoplasmocytic cells. Independent of the suitability of individual channels as therapeutic targets, the identification of a Kv phenotype from tumor specimens could have a diagnostic value of its own. Our results demonstrate that Kv1.5, and to some extent Kv1.3, are aberrantly expressed in a number of human cancers. These channels could serve both as novel markers of the metastatic phenotype and as potential new therapeutic targets. The concept of Kv channels as therapeutic targets or prognostic biomarkers attracts increasing interest and warrants further investigation.