Examination of a Unique T Cell Subset TCD40 in Type 1 Diabetes
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wild-type (WT) T cells. This defect is largely rescued by the addition of recombinant human IL-2, suggesting that Foxq1 is required for optimal production of IL-2 and consequently, robust T cell proliferation. Accordingly, in in vitro luciferase assays, Foxq1 augmented transcriptional activity of the IL-2 transactivator NF-kB while mutant Foxq1 did not retain this function. Finally, Foxq1-mutant mice exhibited reduced susceptibility to the progression of experimental autoimmune encephalomyelitis than their WT counterparts. Thus, Foxq1 is essential for helper T cell activation and autoaggressive T cell responses in vivo, likely via its ability to potentiate NF-kB activity and IL-2 production. doi:10.1016/j.clim.2007.03.516 Sa.130 Human Bone Marrow Mesenchymal Stem Cells Support Polyclonal Stimulation of Human B Cells Elisabetta Traggiai, PhD, Institute G Gaslini, Genova, Italy, Alberto Martini, MD/PhD, Institute G Gaslini, Genova, Italy, Antonio Uccelli, MD/PhD, Department of Neurosciences, Ophthalmology and Genetics, Genova, Italy, Lorenzo Moretta, MD/PhD, Institute G Gaslini, Genova, Italy, Federica Benvenuto, PhD, Department of Neurosciences, Ophthalmology and Genetics, Genova, Italy, Marco Gattorno, MD, Institute G Gaslini, Genova, Italy To investigate the possible application of bone marrow (BM) mesenchymal stem cells (MSCs) in Systemic Lupus Erythematosus (SLE), an autoimmune disease in which B cells play a pivotal role, we studied the interaction of B cell subsets isolated from healthy donor and pediatric SLE patients with human BM MSCs. We isolated from periph- eral blood of healthy donors: a) immature transitional B cells, b) naive B cells, c) IgM memory and d) switch memory B cells. BM MSCs promoted proliferation and differentiation into immunoglobulin secreting cells of transitional and naive B cells stimulated with CpG 2006 in the absence of BCR triggering, and strongly enhanced proliferation and differentiation of both memory B cell populations. Furthermore, both proliferation and differ- entiation into plasma cells of CD19+ B cells isolated from pediatric SLE patients were enhanced by BM MSCs upon polyclonal stimulation. Inhibition of T cell proliferation by MSCs was suggested to be dependent on INF-g€ . To test whether INF-g€ could have an effect on the B cell response under the influence of MSCs, we co-cultured B cell subsets with MSC in the presence of human recombinant INF-ï §ï€®ï€ After 4 days of culture both proliferation and differentiation into plasma cells of all B cell subsets stimulated with CpG, soluble CD40L and anti- Ig were inhibited in both healthy donors and SLE patients. These data show the complexity of the cross-talk between MSCs and B cell and how the microenviroment in which the interaction take place could influence the outcome of the immune response. doi:10.1016/j.clim.2007.03.517 Sa.131 Examination of a Unique T Cell Subset TCD40 in Type 1 Diabetes David Wagner, Assistant Professor, Webb-Waring Institute, Denver, CO The identification of autoaggressive T cells in human disease has proven very difficult. We have discovered a unique T cell subset described as CD4lo and expressing the CD40 receptor termed TCD40. These T cells are significantly expanded in T1D but not T2D or control subjects. A portion of TCD40 cells respond to pre-pro-insulin, GAD peptides, and human islets. These T cells are expanded in diabetes high susceptibility HLA (DR3, DR4, DQ8) subjects, but are also expanded when T1D subjects do not possess any of the high susceptibility HLAs. TCD40 cells remain at expanded percentages in long-term diabetic subjects, suggesting that CD40 is not merely a Tcell activation marker. Interestingly, non-autoimmune subjects carrying DR3, DR4 or DQ8 do not have expanded TCD40 cells. Mechanistic differences in induction of RAG1 and RAG2 are seen between T1D and control subjects. Examination of TRAV usage in T1D and controls demonstrate prominent differences including the detection of TRAV8 in the periphery. TCD40 cells achieve effector status synthesizing predominantly Th1 cytokines. These data suggest a unique T cell population that may be predictive of autoimmunity. doi:10.1016/j.clim.2007.03.518 Sa.132 Effects of Class II/CLIP Affinity on the Class II Antigen Presentation Pathway in the Context of Autoimmunity Cornelia Rinderknecht, Graduate Student, Stanford University, Department of Pediatrics, San Carlos, CA, Tatiana Catanzarite, Student, Stanford University, Department of Pediatrics, Stanford, CA, Michael Belmares, Scientist, Arbor Vita Corporation, Sunnyvale, CA, Elizabeth Mellins, Associate Professor, Stanford University, Department of Pediatrics, Stanford, CA, Susan Kovats, Assistant Member, Oklahoma Medical Research Foundation, Arthritis and Immunology Research Program, Oklahoma City, OK Several MHC class II alleles linked with autoimmune diseases form unusually low-stability complexes with class II- associated invariant chain peptides (CLIP), leading us to hypothesize that this is an important feature contributing to disease pathogenesis. To investigate cellular consequences of altering class II/CLIP affinity, we evaluated invariant chain (Ii) mutants with increased CLIP affinity for two murine class II alleles, I-Ed and I-Ag7, which have low affinity for wt CLIP. I-Ed is associated with a mouse model of spontaneous, autoimmune joint inflammation, and I-Ag7 is associated with models of diabetes (NOD) and arthritis (KRN). Single amino acid mutations were made in murine Ii. Pulse-chase/co- immunoprecipitation analysis of I-Ed or I-Ag7 and CLIP was used to identify physiologically relevant CLIP mutants that are of high affinity but remain DM-sensitive. An increase in CLIP affinity for I-Ed or I-Ag7 resulted in increased cell- S119 Abstracts
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Transcript of Examination of a Unique T Cell Subset TCD40 in Type 1 Diabetes
wild-type (WT) T cells. This defect is largely rescued bythe addition of recombinant human IL-2, suggesting thatFoxq1 is required for optimal production of IL-2 andconsequently, robust T cell proliferation. Accordingly, in invitro luciferase assays, Foxq1 augmented transcriptionalactivity of the IL-2 transactivator NF-kB while mutantFoxq1 did not retain this function. Finally, Foxq1-mutantmice exhibited reduced susceptibility to the progression ofexperimental autoimmune encephalomyelitis than theirWT counterparts. Thus, Foxq1 is essential for helper T cellactivation and autoaggressive T cell responses in vivo,likely via its ability to potentiate NF-kB activity and IL-2production.
doi:10.1016/j.clim.2007.03.516
Sa.130 Human Bone Marrow Mesenchymal StemCells Support Polyclonal Stimulation of Human BCellsElisabetta Traggiai, PhD, Institute G Gaslini, Genova, Italy,Alberto Martini, MD/PhD, Institute G Gaslini, Genova, Italy,Antonio Uccelli, MD/PhD, Department of Neurosciences,Ophthalmology and Genetics, Genova, Italy, LorenzoMoretta, MD/PhD, Institute G Gaslini, Genova, Italy,Federica Benvenuto, PhD, Department of Neurosciences,Ophthalmology and Genetics, Genova, Italy, MarcoGattorno, MD, Institute G Gaslini, Genova, Italy
To investigate the possible application of bone marrow(BM) mesenchymal stem cells (MSCs) in Systemic LupusErythematosus (SLE), an autoimmune disease in which Bcells play a pivotal role, we studied the interaction of Bcell subsets isolated from healthy donor and pediatric SLEpatients with human BM MSCs. We isolated from periph-eral blood of healthy donors: a) immature transitional Bcells, b) naive B cells, c) IgM memory and d) switchmemory B cells. BM MSCs promoted proliferation anddifferentiation into immunoglobulin secreting cells oftransitional and naive B cells stimulated with CpG 2006in the absence of BCR triggering, and strongly enhancedproliferation and differentiation of both memory B cellpopulations. Furthermore, both proliferation and differ-entiation into plasma cells of CD19+ B cells isolated frompediatric SLE patients were enhanced by BM MSCs uponpolyclonal stimulation. Inhibition of T cell proliferation byMSCs was suggested to be dependent on INF-g€ . To testwhether INF-g€ could have an effect on the B cellresponse under the influence of MSCs, we co-cultured Bcell subsets with MSC in the presence of humanrecombinant INF-ï §ï€®ï€ After 4 days of culture bothproliferation and differentiation into plasma cells of all Bcell subsets stimulated with CpG, soluble CD40L and anti-Ig were inhibited in both healthy donors and SLE patients.These data show the complexity of the cross-talk betweenMSCs and B cell and how the microenviroment in whichthe interaction take place could influence the outcome ofthe immune response.
doi:10.1016/j.clim.2007.03.517
Sa.131 Examination of a Unique T Cell Subset TCD40in Type 1 DiabetesDavid Wagner, Assistant Professor, Webb-Waring Institute,Denver, CO
The identification of autoaggressive T cells in humandisease has proven very difficult. We have discovered aunique T cell subset described as CD4lo and expressing theCD40 receptor termed TCD40. These T cells are significantlyexpanded in T1D but not T2D or control subjects. A portionof TCD40 cells respond to pre-pro-insulin, GAD peptides,and human islets. These T cells are expanded in diabeteshigh susceptibility HLA (DR3, DR4, DQ8) subjects, but arealso expanded when T1D subjects do not possess any of thehigh susceptibility HLAs. TCD40 cells remain at expandedpercentages in long-term diabetic subjects, suggesting thatCD40 is not merely a T cell activation marker. Interestingly,non-autoimmune subjects carrying DR3, DR4 or DQ8 do nothave expanded TCD40 cells. Mechanistic differences ininduction of RAG1 and RAG2 are seen between T1D andcontrol subjects. Examination of TRAV usage in T1D andcontrols demonstrate prominent differences including thedetection of TRAV8 in the periphery. TCD40 cells achieveeffector status synthesizing predominantly Th1 cytokines.These data suggest a unique T cell population that may bepredictive of autoimmunity.
doi:10.1016/j.clim.2007.03.518
Sa.132 Effects of Class II/CLIP Affinity on the Class IIAntigen Presentation Pathway in the Context ofAutoimmunityCornelia Rinderknecht, Graduate Student, StanfordUniversity, Department of Pediatrics, San Carlos, CA,Tatiana Catanzarite, Student, Stanford University,Department of Pediatrics, Stanford, CA, Michael Belmares,Scientist, Arbor Vita Corporation, Sunnyvale, CA, ElizabethMellins, Associate Professor, Stanford University,Department of Pediatrics, Stanford, CA, Susan Kovats,Assistant Member, Oklahoma Medical Research Foundation,Arthritis and Immunology Research Program, OklahomaCity, OK
Several MHC class II alleles linked with autoimmunediseases form unusually low-stability complexes with class II-associated invariant chain peptides (CLIP), leading us tohypothesize that this is an important feature contributing todisease pathogenesis. To investigate cellular consequencesof altering class II/CLIP affinity, we evaluated invariant chain(Ii) mutants with increased CLIP affinity for two murine classII alleles, I-Ed and I-Ag7, which have low affinity for wt CLIP.I-Ed is associated with a mouse model of spontaneous,autoimmune joint inflammation, and I-Ag7 is associated withmodels of diabetes (NOD) and arthritis (KRN). Single aminoacid mutations were made in murine Ii. Pulse-chase/co-immunoprecipitation analysis of I-Ed or I-Ag7 and CLIP wasused to identify physiologically relevant CLIP mutants thatare of high affinity but remain DM-sensitive. An increase inCLIP affinity for I-Ed or I-Ag7 resulted in increased cell-
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