Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Engraftment of PBMC from SLEand ACL Donors into BALB-Rag2/ IL2Rgc-KO Mice: A Promising Model for Studying SLE.
Koo4, Gloria C., Salmon2, Jane E., Perino3, Giorgio, Qing1, Xiaoping, Redecha1, Patricia B., Vukelic2, Milena, Andrade1, Danieli
Our goal was to construct a SLE mouse model that resembles the human disease and has human cells which may be studied to define pathophysiology and targeted for treatments.
We infused peripheral blood mononuclear cells (PBMC) from SLE patients into the severe combined immuno-deficient mouse, BALB- Rag2 -/- IL2Rgc -/- mice (DKO), which lack T, B and NK cells. PBMC from 5 SLE patients (5 anti-dsDNA positive and 2 of these were ACL positive) and 4 normal donors (ND) at 35 ×106/mouse were infused IV and IP to non- irradiated 45 weeks old DKO mice, 25 DKO mice/donor. We evaluated the engraftment of human CD45+ cells and lymphocyte subsets. We monitored the plasma human IgG concentration, anti-dsDNA antibody, anti-cardiolipin (CL) antibody, proteinuria, and performed histologic examination of the liver and kidney.
We found 100% engraftment of human PBMC in 38 DKO mice studied. In both SLE-DKO and ND-DKO mice, we found 510% human CD45+ cells in the PBMC fraction 2 weeks post engraftment, and these cells expanded to 5080% at 46 weeks. PBMC from both SLE-DKO and ND-DKO mice contained 7090% human CD3+ cells. In SLE-DKO mice, as reported in SLE patients, there were fewer CD3+4+cells (5.1±1.9 %) and more CD3+8+ cells (81.6± 3.9 %), significantly different from that in ND-DKO mice, which had normal distribution of CD3+CD4+ (66.2 ±2.5 %) and CD3+8+ (16.5 ± 2.1%) cells in the PBMC (SLE-DKO vs. ND-DKO: P<1.3E-08 for CD4+, P< 2.1E-07 for CD8+ populations). CD19+ B cells were present mainly in the peritoneum and bone marrow, and CD11c cells were found in the spleen. Human CD45+ cells, assessed by FACS analyses, were also present in the lung, liver, and kidney. There was no significant difference in plasma human IgG levels between SLE-DKO and ND-DKO mice (32.3 ±13 and 26.4 ±7 ug/ml, respectively). Anti-dsDNA antibodies were found in SLE-DKO mice (3.97 ± 1.6 IU/ml) and lower in ND-DKO mice (2.2 ± 0.7 IU/ml, DKO=1 ± 0.02), but not significantly different between the 2 groups (P<0.25). Strikingly, levels of ACL antibody were higher in all SLE-DKO mice infused with cells from an ACL positive patient (SLE-DKO, 8.5 ±1.4 vs ND-DKO, 3.6 ± 0.2 GCL-U; P<0.019, un-engrafted DKO, 3.6 ± 0.8 GCL-U). SLE-DKO mice had evidence of nephritis. After 46 weeks of engraftment, they had proteinuria, (SLE-DKO: 93.5 ± 25 ug/mg; ND-DKO: 22 ± 3.3 ug/mg albumin/creatinine; P<0.01; un-engrafted DKO:17.8 ug/mg). Kidney sections showed human IgG deposits. In SLE- DKO mice engrafted with PBMC from an ACL-positive patient, we found micro-thrombi in the glomeruli of the kidney, and the liver showed fibrosis and necrosis. By 45 weeks after engraftment, 50% of the SLE-DKO mice died, whereas ND-DKO lived >7 weeks (SLE-DKO vs ND-DKO, P<0.04).
We have created a novel humanized SLE-DKO mouse that exhibits many characteristics of immunologic and clinical features of SLE. Importantly, we recapitulated clinical manifestations of APS in mice infused with PBMC from an ACL-positive patient. The SLE - DKO mouse promises to be an excellent model to study the pathophysiology of SLE and test human-specific therapies. Supported in part by NIH fund, R01 AR03889 and CNPQ 200591/2008-8.
To cite this abstract, please use the following information:
Koo, Gloria C., Salmon, Jane E., Perino, Giorgio, Qing, Xiaoping, Redecha, Patricia B., Vukelic, Milena, et al; Engraftment of PBMC from SLEand ACL Donors into BALB-Rag2/ IL2Rgc-KO Mice: A Promising Model for Studying SLE. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :427