Consistent with the histology and immunohistochemistry findings, we detected an average of 7

Consistent with the histology and immunohistochemistry findings, we detected an average of 7.8 times more human Doxifluridine GAPDH expression in kidneys of 3 different P5-DKO mice (average relative expression=16839) compared to ND-DKO (average relative expression=2215, n=3 mice from 2 different ND donors, P<0.049). A correlation of SLE disease phenotype was observed in the SLE-DKO mice engrafted with PBMC from APS patient (P5) whose cells were engrafted from samples obtained 2 different times using 34 mice at each time point. mice infused with human PBMC. In both SLE-DKO and ND-DKO mice, 5080% human CD45+ cells were observed in PBMC fraction 46 weeks post engraftment, with 7090% CD3+ cells. There were fewer CD3+4+cells (5.52.1%) and more CD3+8+cells (79.43.6%) in the SLE-DKO mice, as in the SLE patients. CD19+B cells and CD11c+Monocytic cells were found in the spleen, lung, liver and bone marrow. There was no significant difference in plasma human IgG levels and anti-dsDNA antibodies between SLE-DKO and ND-DKO mice. Levels of aCL antibody were significantly higher in all SLE-DKO mice infused with PBMC from a SLE patient with high titers of aCL Rabbit polyclonal to CD10 antibodies. SLE-DKO mice had proteinuria, human IgG deposits in the kidneys and shorter life span. In SLE- DKO mice engrafted from the aCL-positive patient, we found micro-thrombi and infiltration of CD3+, CD8+ and CD19+ cells in the glomeruli, recapitulating APS in these mice. == Conclusion == A novel humanized SLE-DKO mouse is established, exhibiting many characteristics of immunologic and clinical features of SLE. == INTRODUCTION == Systemic lupus erythematosus (SLE) is a prototypic multisystem autoimmune disease characterized by autoantibodies and immune complex deposition. Anti-double stranded DNA antibodies (anti-dsDNA Ab) and antiphospholipid antibodies (APL Ab) are present in 70% and 3040% of patients respectively (13). Although it is presumed that autoantibodies contribute to disease pathogenesis, the cause of SLE remains unclear and therapies are limited. While studies of spontaneous or induced of mouse models have advanced our understanding of SLE, each strain has unique advantages and disadvantages, no strain is a perfect phenocopy of human Doxifluridine SLE, and effective treatments in SLE mouse models often do not translate to human disease (3,4). To overcome these limitations and attempt to mimic the pathophysiology of human SLE, we infused peripheral blood mononuclear cells (PBMC) of SLE patients into a newly generated inbred severe-combined-immunodeficient (SCID) mouse, the BALB-Rag2/ IL2Rgc/ (double knock-out, DKO) mouse, which lacks T, B and NK cells. (5,6) Both the Rag2, recombination activation gene 2, responsible for rearrangement of T and B cell receptors and the IL2R gamma chain (receptor to IL2, 4, 7, 9, 15 and 21) required by T/NK cells, are deleted in DKO mice. As such, there is no detectable murine IgG or IgM, (5,7) A similar IL2RgcKO mouse was constructed on the NOD/SCID background resulting in NSG/NOG mice (7,8). The SCID genotype of NSG/NOG mice was derived from a spontaneous point mutation of DNA-dependent protein kinase in CB17(BALB/c)/SCID mouse (9,10). Both DKO and NSG/NOG mice have been successfully used to engraft human CD34+ stem cells, reconstituting the full components of human hematopoietic system (7,8,11). The NSG/NOG mice have been used extensively for tumor xenografts (7,8). The CB17/SCID, DKO and NSG/NOG mice have also been used to engraft human PBMC and cord blood mononuclear cells to study HIV and vaccines. (11,12) We chose to study DKO mice rather than NSG/NOG mice, because the latter are deficient in lytic complement activity ((13), Jackson Laboratory web-site), a key pathway implicated in SLE. Previous studies support the rationale and feasibility of our approach. Two groups of investigators infused 1530 million PBMC from SLE patients into CB17/SCID mice and detected anti-dsDNA antibodies in the circulation and mouse C3 deposition in the kidneys after 812 weeks (14,15). Their work was limited because only 65% of mice were successfully engrafted with human cells and they required large numbers of PBMC which is challenging in SLE patients who are often lymphopenic. (16,17). We hypothesized that the engraftment of SLE PBMC into DKO mice would consistently generate SLE disease and provide a unique and improved humanized mouse model of SLE to facilitate translational studies with human cells as targets for therapy. We report our observations on DKO mice, engrafted with PBMC from 5 SLE patients, including Doxifluridine 2 with APS and 4 normal donors (ND). == MATERIALS AND METHODS == == Subjects == Approximately 1030 ml of heparinized peripheral blood was obtained from 4 disease-free consented ND volunteers and 5 patients who fulfilled ACR criteria for SLE, 2 of which had APS. The exclusion criteria were pregnancy and acute infection. Clinical characteristics of the patients are detailed inTable 1. All patients gave informed consent for this study, and the study was approved by the Institutional Review Board at Hospital for Special Surgery. == Table 1. == Description of SLE patients and SLE-DKO mice studied in this report. SLEDAI = Systemic Lupus Erythematosus Disease Activity Index; anti-ds-DNA = anti- double strand DNA antibodies (abnormal is >10 IU/ml); (IU) = international units; aCL = anticardiolipin antibodies (abnormal is >15 GPL U); MMF = mycophenolate mophetil; HXQ = hydroxychloroquine; MP = methylprednisolone Engraftment of SLE-DKO mice: P1: n=2; P2: n=3; P3: n=3; P4: n=2; P5: n=7. == Mice and engraftment of human PBMC == Adult male and female DKO (BALB-Rag2/ IL2Rgc/) breeding pairs were.