LILRA3 Promotes Lupus-like Chronic Graft-versus-Host Disease by Expansion of Follicular Helper T Cells and Anti-dsDNA Autoantibodies

Yundi Tang¹, Yuxuan Wang ¹, Yundong Zou ¹, Mengru Liu ¹, Yan Du ¹ and Jianping Guo ¹, ¹Department of Rheumatology and Immunology, Peking University People's Hospital, Beijing, China (People's Republic)

Meeting: 2019 ACR/ARP Annual Meeting

Keywords: cellular response and autoantibody production, knock-in mice, LILRA3, lupus-like disease

Session Information

Date: Sunday, November 10, 2019

Title: SLE – Animal Models Poster

Session Type: Poster Session (Sunday)

Session Time: 9:00AM-11:00AM

Background/Purpose: Leukocyte immunoglobulin-like receptor A3 (LILRA3) is a soluble member of LILR family. We previously reported that LILRA3 is a novel genetic risk for multiple autoimmune diseases, including systemic lupus erythematosus (SLE). However, it is unclear how LILRA3 contributes to the pathogenesis of SLE. This study was undertaken to examine the in vivo role of LILRA3 and its possible mechanism(s) in development of lupus in a chronic graft-versus-host disease (cGVHD) model.

Methods: To functionally study the role of LILRA3 in lupus pathogenesis, we generated a novel LILRA3 knock-in (LILRA3-KI) mouse and evaluated clinical and immunological phenotypes in the bm12-induced cGVHD model. Human LILRA3 gene (Gene ID: 11026) was inserted into Rosa26 allele in C57BL/6 (B6) mice based on Cas9/sgRNA system. The cGVHD was induced by an intraperitoneal injection of the bm12 donor splenocytes into recipients, either B6 wild-type (B6-WT) or LILRA3-KI mice. Mice were assessed for the development of splenomegaly, immune cellular response, autoantibody production, and renal pathology.

Results: Compared with B6-WT recipient mice, the LILRA3-KI mice displayed a more pronounced lupus-like phenotype and immune response, which includes an apparent spleen enlargement (p < 0.001); expansion of Tfh cells (p < 0.001), germinal center (GC) B cells (p < 0.01), and plasma B cells (p < 0.001); and elevated levels of serum anti-double-stranded DNA IgG autoantibodies (p < 0.001).

Conclusion: Our data indicate that LILRA3 promotes lupus-like disease probably through the excessive expansion of Tfh, GC B, and plasma cells, and subsequently leading to an excessive production of anti-dsDNA autoantibodies.

Figure 1. Construction strategy of the LILRA3 knock-in mice. Humanized LILRA3 knock-in -LILRA3-KI- mice were constructed on C57BL/6 background. A full-length sequence of human LILRA3 gene -Gene ID: 11026- was inserted into the C57BL/6 Rosa26 allele based on CRISPR-Cas9 technology -A-. LILRA3 expression was confirmed by southern blot -B-, PCR -C-, and ELISA -D-. After cGVHD, serum LILRA3 was highly expressed in bm12→KI mice at both days 14 and 28 -E-. The bm12→KI mice showed a significant aggravation of splenomegaly -F-. Results from F: data were obtained from 2 independent experiments at day 14 -B6→B6: n=9; bm12→B6: n=12; bm12→KI: n=12-. At day 28, data were obtained from a single experiment -B6→B6: n=4; bm12→B6: n=6; bm12→KI: n=4-. Data are displayed as mean±SD. ** p < 0.01, *** p < 0.001.

Figure 2. Increased expansion of Tfh cells in LILRA3-KI cGVHD mice. On days 14 and 18, the frequencies of CD4+IFNγ+ Th1 cells -A-, CD4+IL-17A+ Th17 cells -B-, CD4+CD25+FoxP3+ Tregs -C-, and CD4+PD-1+CXCR5+ Tfh cells -D- from splenocytes were determined by flow cytometry. At day 14, data were obtained from 2 independent experiments -B6→B6: n=9; bm12→B6: n=12; bm12→KI: n=12-. At day 28, data were obtained from a single experiment -B6→B6: n=4; bm12→B6: n=6; bm12→KI: n=4-. Data are displayed as mean±SD. * p < 0.05, ** p < 0.01, *** p < 0.001.

Figure 3. Increased expansion of GC B, plasma cells and anti-dsDNA autoantibody production in LILRA3-KI cGVHD mice. On days 14 and 18, the frequencies of CD19+FAS+GL-7+ GC B cells -A-, and CD19+CD138+B220- plasma cells -B- from splenocytes were determined by flow cytometry. Serum levels of anti-dsDNA IgG -C-, and ANA -D- were measured by ELISA. At day 14, data were obtained from 2 independent experiments -B6→B6: n=9; bm12→B6: n=12; bm12→KI: n=12-. At day 28, data were obtained from a single experiment -B6→B6: n=4; bm12→B6: n=6; bm12→KI: n=4-. Data are displayed as mean±SD. ** p < 0.01, *** p < 0.001.

Disclosure: Y. Tang, None; Y. Wang, None; Y. Zou, None; M. Liu, None; Y. Du, None; J. Guo, None.

To cite this abstract in AMA style:

Tang Y, Wang Y, Zou Y, Liu M, Du Y, Guo J. LILRA3 Promotes Lupus-like Chronic Graft-versus-Host Disease by Expansion of Follicular Helper T Cells and Anti-dsDNA Autoantibodies [abstract]. Arthritis Rheumatol. 2019; 71 (suppl 10). https://acrabstracts.org/abstract/lilra3-promotes-lupus-like-chronic-graft-versus-host-disease-by-expansion-of-follicular-helper-t-cells-and-anti-dsdna-autoantibodies/. Accessed .

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