Corporation, Cell Biology, Menlo Park, CA, Jerrod Denham,Senior Manager, Geron Corporation, Product Development,Menlo Park, CA

A major concern in the use of allotransplantation of humanembryonic stem cell (hESC)-derived cell therapies is thepossibility of rejection by the host's immune system. We havepreviously reported that the undifferentiated hESC lines H1,H7 and H9 possess unique immunological properties whichmay make them less susceptible to rejection. To determine ifdifferentiation alters the immunogenicity of hESCs, we choseto study hESC-derived oligodendrocyte progenitor cells (OPC)that have the potential for clinical application to treatpatients with spinal cord injury. Undifferentiated H1 and H1-derived OPCs express low tomoderate levels of surface HLA-A,B,C antigens and lack surface expression of HLA-DR,DP,DQantigens. In an in vitro mixed lymphocyte reaction (MLR)assay, both hESCs and OPCs stimulated weak T cell prolifera-tion compared to allogeneic dendritic cells. Both undiffer-entiated hESCs (uhESCs) and their differentiated OPCderivatives were largely resistant to NK cell-mediated lysis.We have also investigated whether hESC-derived OPCs aresusceptible to the presence of anti-Neu5Gc antibodies innormal human sera. We observed that of ten sera from normalhealthy individuals representing all four blood groups, uhESCsshowed no susceptibility to lysis and eight sera did not showmeasurable cytotoxicity against OPCs. The same sera whentested against murine embryonic fibroblasts (MEFs) demon-strated significant complement-dependent lysis. Takentogether, these data show that the hESC-derived OPCs retainsome of the unique immunological properties of the parentalcell line from which they were differentiated.

doi:10.1016/j.clim.2007.03.148

Su.110 Adhesion Molecules in Pancreatitis-associated Lung InjuryRoman Vatseba, Medical University, Lviv, Ukraine, SergeChooklin, Medical University, Lviv, Ukraine, Myroslav Lyba,Medical University, Lviv, Ukraine

Respiratory failure is typical for acute necrotizing pan-creatitis. Unfortunately, the pathogenesis of these changes isfully unknown. The role of the endothelium in the humanacute pancreatitis is still unclear. Applying the ELISAtechnique, plasma levels of soluble E-selectin (sE-selectin)and sICAM-1 were studied in 51 patients with acutepancreatitis. Twenty-five of them had respiratory complica-tions. In this study enrolled patients who admitted to clinicwithin 48 hours after disease onset. The control groupcompiled 10 healthy volunteers. Already after admission theincreased levels of adhesion molecules were noted in allpatients. By that, the highest levels were observed inpatients with lung injury. During first 7 days plasma levelsof sE-selectin and sICAM-1 practically did not change inpatients with necrotizing pancreatitis, while in patients withthe pancreatitis-associated lung injury its levels graduallyincreased starting from the third day. There was a clearcorrelation between sE-selectin, sICAM-1 and severity ofhemodynamic compromise was established. The intensity ofendothelial activation, measured by adhesion molecules

concentration, considered to be key features of systemicinflammation in severe pancreatitis. These data pointed onthe role of adhesion molecules in the pathogenesis ofpancreatitis-associated lung injury. Blockade of ICAM-1 andE-selectin synthesis and its receptors may be a novel targetin the management of pancreatitis-associated lung injury.

doi:10.1016/j.clim.2007.03.149

Su.111 Aire Deficient Mice—A Model forAutoimmune Lung DiseaseAnthony Shum, Clinical Fellow, University of California, SanFrancisco Department of Medicine, San Francisco, CA, JasonDeVoss, Postdoctoral Fellow, University of California, SanFrancisco Diabetes Center, San Francisco, CA, MarkAnderson, Assistant Professor, University of California, SanFrancisco Diabetes Center and Department of Medicine, SanFrancisco, CA

Aire deficient mice have a mutation for the gene encodingAIRE, a transcription factor that drives the ectopic expressionof organ-specific antigens in the thymus. A deficiency in AIREresults in a breakdown of central tolerance toward self-antigens resulting in organ-specific autoimmune disease. TheAIRE knockout mouse is a model for Autoimmune Polygland-ular Syndrome Type 1, a disorder characterized by poly-glandular autoimmune disease. Pulmonary manifestations,while rare, have been reported, including lymphocyticinterstitial pneumonitis and bronchiolitis obliterans organiz-ing pneumonia. Our goals are to 1) understand themechanismof autoimmune-mediated attack and its relationship to thethymus 2) identify lung specific auto-antigens. Methods: AIREknockout mice were examined for lung histology andimmunohistochemistry. Serum from knockout mice was usedfor immunoblotting and indirect immunofluorescence. Flowcytometry and intracellular cytokine staining was performedon lymphocytes isolated from AIRE knockout lungs. Results:Lung histology reveals perivascular and peribronchiolarmononuclear inflammation. Immunoblots reveal a predomi-nant antigen at 84 kilodaltons. The presence of autoantibodyto this antigen correlates with the presence of histologicinfiltrates. Indirect immunofluorescence on lung sectionsfrom unaffected mice show staining of bronchiolar epithe-lium. Immune cell subtypes visualized on sections of knockoutmice reveal a predominance of CD4+ cells. Flow cytometricanalysis of lymphocytes from lungs of knockout mice confirmthe predominance of CD4+ T cells. Intracellular cytokinestaining of lymphocytes reveal the predominance of the TH1cytokine IFN-γ. Conclusions: AIRE deficient mice are apromising model of spontaneous autoimmune lung diseaseoffering the potential to identify lung auto-antigens.

doi:10.1016/j.clim.2007.03.150

Su.112 The XX Sex Chromosome Complement, ascompared to the XY, Confers Greater Susceptibility toExperimental Autoimmune Diseases — EAE and SLEDeborah Smith, Doctoral Candidate, University of California,Los Angeles Neuroscience, Los Angeles, CA, Sienmi Du,Research Assistant, University of California, Los Angeles

S178 Abstracts

Neurology, Los Angeles, CA, Seema Tiwari-Woodruff,Associate Professor, University of California, Los AngelesNeurology, Los Angeles, CA, Arthur P. Arnold, Chair,Distinguished Professor, University of California, Los AngelesPhysiological Science, Los Angeles, CA, Jennifer K. King,Post-Residency Fellow, University of California, Los Angeles,Rheumatology, Los Angeles, CA, Ram Raj Singh, Professorof Medicine, University of California, Los Angeles Medicine-Rheumatology, Los Angeles, CA, Rhonda R. Voskuhl,Professor in Residence, University of California, LosAngeles Neurology, Los Angeles, CA

The majority of autoimmune diseases are more commonin women as compared to men. This may be attributed todifferences in sex hormones, sex chromosomes or both. Todetermine the contribution of sex chromosomes to sexdifferences in susceptibility to autoimmune disease, we usedanimal models characterized by a known female preponder-ance, experimental autoimmune encephalomyelitis (EAE)and pristane-induced lupus, each in SJL mice. Mice whichhave Sry, the gene that encodes for testicular development,deleted from the Y chromosome were backcrossed onto theSJL strain, resulting in EAE and lupus-susceptible mice whichdiffer in their complement of sex chromosomes, while havingthe same gonadal type, thereby permitting assessment ofsex chromosome effects not confounded by differences insex hormones (ovary bearing XX vs. XY- mice). Whencomparing EAE in ovariectomized XX vs. XY- SJL mice,disease was more severe and there was more inflammation inthe spinal cords of mice with the XX sex chromosomecomplement. Also, when lupus was induced in ovariecto-mized XX vs. XY- SJL mice, mortality, nephritis and autoanti-body levels were each greater in mice with the XX sexchromosome complement. The differences in susceptibilityto EAE and lupus also occurred when comparing castrated XXSry versus XY- Sry mice (testis bearing mice). This is the firstevidence that XX sex chromosome complement, as comparedto XY, confers greater susceptibility to two immunopatholo-gically distinct diseases. This may be relevant to theincreased susceptibility of women to a variety of distinctautoimmune diseases.

doi:10.1016/j.clim.2007.03.151

Su.113 Expression of the Renal Antigen Neprhin byHuman Medullary Thymic Epithelial CellsMichael Tasch, Senior Fellow, University of Washington,Department of Medicine, Seattle, WA, Kimberly Muczynski,Associate Professor, University of Washington, Departmentof Medicine, Seattle, WA, Anne Stevens, Assistant Professor,University of Washington, Department of Pediatrics,Seattle, WA, J. Lee Nelson, Professor, Fred HutchinsonCancer Research Center, Division of Clinical Research,Seattle, WA

Idiopathic nephrotic syndrome, a set of glomerular pa-thologies often leading to end-stage renal disease, is asso-ciated with disturbances in Tcell function. This has led to theview that these diseases are a consequence of T cellmediated autoimmunity, though the relevant autoantigen(s)remain unidentified. Nephrin is a possible target for

autoimmunity in the kidney. The protein product of theNPHS1 gene and an essential component of the glomerularfiltration barrier, nephrin is expressed proximal to auto-immune renal lesions and conforms to the definition of atissue restricted antigen (TRA). Since intrathymic expressionof other TRAs has been implicated in the establishment ofcentral tolerance and protection from organ-specific auto-immunity, we hypothesized that nephrin is expressed by cellsof the human thymus. RT-PCR analysis showed that NPHS1mRNA is present in all human thymi (N=12) tested. Usingprimer sets flanking sequences encoding immunoglobulin-like domains, we showed that the thymic-specific transcriptappears identical to that from kidney. FACS-purified CD326+,HLA-DR+ medullary thymic epithelial cells (mTEC) exhibitedthe highest concentration of NPHS1 transcripts. Immuno-fluorescence analysis showed that nephrin protein isexpressed in thymus sections. Nephrin exhibited a predomi-nantly medullary pattern of expression, co-localizing withHLA-DR and cytokeratin, consistent with mTEC, althoughinfrequent nephrin-positive cells were seen in the cortex andcapsule also. Nephrin staining also showed distinct intracel-lular patterns including surface, intracellular granules andpunctate structures. These data provide a strong rationalefor exploring nephrin's role in negative selection and the roleof nephrin-specific T cells in human nephrotic syndrome.

doi:10.1016/j.clim.2007.03.153

Su.114 Low-dose of Local Radiation Treatment CanInhibit the Progression of ExperimentalAutoimmune Nephritis by Promoting ApoptosisM. S. Razzaque, Research Scientist, Department ofPathology, Nagasaki University, Nagasaki, Japan, L. Diange,Research Scientist, Department of Pathology, NagasakiUniversity, Nagasaki, Japan, A. Nazneen, ResearchScientist, Department of Pathology, Nagasaki University,Nagasaki, Japan, T. Taguchi, Professor, Department ofPathology, Nagasaki University, Nagasaki, Japan

Autoimmune crescentic glomerulonephritis (CrGN) is arapidly progressive form of nephritis and usually resistant totherapeutic intervention. Apoptosis plays important role inresolution of CrGN. We investigated the effects of localradiation treatment in the progression of CrGN in rats. Threeexperimental groups were studied; Group-I: sham-operatedcontrol (n=12); Group-II: intravenous injection of rabbitanti-rat GBM antibody (nephrotoxic serum, NTS) (n=23); andGroup-III: a single low-dose of 0.5 Gy X-ray radiationtreatment to local bilateral kidneys at 6, 13, 20, and27 days after NTS injection (n=55). In Group-III, the levelof BUN and serum creatinine was significantly decreasedafter radiation treatment compared with age-matchedGroup-II nephritic rats (pN0.05 or 0.001). Glomerularhypercellularity, crescents, global sclerosis and tubulointer-stitial damage gradually developed throughout the timecourse in Group-II rats, were significantly less (PN 0.05 or0.001) after radiation treatment in Group-III. The expressionof active caspases-3 and -7 was increased for irradiatedkidneys, compared with their corresponding Group-II rats.Western blot analysis showed that 17 kDa active caspase-3and 35 kDa active caspase-7 expressions markedly increased

S179Abstracts