identified that play a pivotal role in the control of auto-immunity and transplantation tolerance in rodents. Recentstudies have shown that immature DC and ex vivo expandedTreg could be potential reagents to promote antigen-specifictolerance in vivo. To date, these works have been carried outmostly in rodents and will need to be validated in primatesbefore being applied in the clinic. In order to bettercharacterise tolerogenic DC and Treg in primates we firstgenerated and characterised different types of DC frommacaque bone marrow (BMDC). Among these cells, the mostimmature BMDC (adherent cells resulting from culture in thepresence of GM-CSF alone) could be good candidates for invivo testing in protocols of tolerance induction. We were alsoable to demonstrate that in the presence of IL-2, semi-mature BMDC (cultured with GM-CSF and IL-4) have theability to expand CD4+CD25+CD127-Foxp3+ macaque Tregcells (25 fold in 7 days) and additionally increase their sup-pressive activity. These results represent an important steptowards the potential use of tolerogenic DC and/or Treg as anadoptive cell therapy to induce antigen-specific tolerance inpre-clinical, non-human primate models.

doi:10.1016/j.clim.2007.03.136

Su.98 Low Doses of Intravenous Immunoglobulin inRenal Transplant Patients with High Levels ofAnti-HLA Panel Reactive Antibodies (PRA)Miguel Rodriguez, Immunologist, Hospital Especialidades,IMSS Department Inmunologia, Guadalajara, Mexico,Alejandro Bautista, Nephrologist, Hospital EspecialidadesIMSS, Department Nephrology, Guadalajara, Mexico,Francisco Monteon, MD, Hospital Especialidades Division ofTransplantes, Guadalajara, Mexico, Felicia Castro,Pharmacobiology Chemist, Hospital Especialidades, Divisionof Transplantes, Guadalajara, Mexico, Efrain Montaño, MD,Hospital Especialidades IMSS, Department InmunologiaClínica, Guadalajara, Mexico, Antonio Flores, MD, HospitalEspecialidades, IMSS Department Nefrologia, Guadalajara,Mexico

Introduction: The renal transplant (RT) is the besttreatment for the patients with End Stage Renal Disease(ESRD). Patient with anti-HLA antibodies has a short graft life.Different studies shown that intravenous immunoglobulin(IVIG) diminishes anti-HLA antibodies. Methods and materi-als: An open, not randomized clinical trial. We used 100mg/kgof IVIG in patient with PRA higher than 305 with negativecrossmatch to donor (XM−) by flow cytometry (FC). Weadministered 3 doses of IVIG 100 mg/kg every other day. Oneweek after the PRA was repeated. Patients with PRA lowerthan 30%, were considered desensitized and proceeded to RT,monitoring the occurrence of rejections and graft survival.Results: We reported 8 patients (3M/5F), age of 22.8 SD2.4 years. Four patients with second RT (50%). PRA previous88.65% (SD 5.65%) Class I and 50.09% (SD 40.32%) Class II. Aftertreatment 7.66% (SD 12.32%) Class I and 11.39% (SD25.37%)Class II. PRA diminished in 7 patients and in 1 patientremained elevated. Five received a RT from living relateddonor, ABO compatible (71.4%) and two of them from cadaver(28.6). The monitoring of this group is 46+–25.7 weeks. Onepatient (from cadaver) presented two rejection crises both

resolved favorably. Creatinine being 0.95 mg/dl (SD 0.4).Creatinine depuration (MDRD)88.6 SD 22.05 ml/min/1.73m2.We did not document any infectious process within the group.Discussion: IVIG in low doses confer a protective effect, inpatients with high PRA. We needmoremonitoring to evaluatethe impact in the long term.

doi:10.1016/j.clim.2007.03.137

Su.99 Efficient Ex Vivo Priming of Naïve Precursorsinto EBV-specific Type-1 CD8+ T Cell Responses fromEBV Seronegative Pediatric HTx Patients RequiresIL-12 and IL-27Diana Metes, Assistant Professor, University of Pittsburgh,Transplantation Surgery, Pittsburgh, PA, Camila Macedo,Postdoctoral Associate, University of Pittsburgh,Transplantation Surgery, Pittsburgh, PA, Walter Storkus,Professor, University of Pittsburgh, Dermatology,Pittsburgh, PA, Iulia Popescu, Research Instructor,University of Pittsburgh, Transplantation Surgery,Pittsburgh, PA, Steve Webber, Professor, University ofPittsburgh, Pediatrics, Pittsburgh, PA

The risk of post-transplant lymphoproliferative disorders(PTLD) is increased in pediatric recipients, and cellularimmunotherapy with EBV specific cytotoxic T lymphocytes(CTLs) represents a promising therapeutic strategy to restorecellular immunity in PTLD patients. Although we wereeffective at priming strong EBV-specific CTL responses fromEBV-seronegative healthy adults using DC-based protocols,similar attempts were unsuccessful for EBV-seronegativepediatric Tx patients. Peripheral blood lymphocytes wereobtained from 5 EBV seronegative HTx patients and werestimulated ex vivo for 10 days with autologous mature DCpulsed with a cocktail of MHC class I-restricted EBV peptidesas follows: (i)DC/peptide only (ii)DC/peptide+ IL-12 (anadjuvant cytokine for promoting Type-1 immunity-IFNgamasecretion) (iii)DC/peptide+ IL-27 (a potent early cytokineregulator of Type-1 commitment) (IV)DC/peptide+IL-12+IL-27.EBV-specific CD8+ T cell responses were screened by flowcytometry and IFNgama ELISPOT assays. The DC/peptide+IL-12+ IL-27 approach yielded the best yields (1.7X), theoptimal EBV-specific CD8+ T cell expansion (from undetect-able to 1.5%+0.5 EBV-tetramer+ CD8 T cells), and optimalEBV specificity (from 3+2 spots/105 to 45+15 spots/105CD8+ T cells in ELISPOT assays). DC/peptide (9+2 spots/105)or the DC/peptide+ IL-12 (12+4 spots/105) protocols wereunsuccessful in this setting. These results suggest thatpriming of functional EBV-specific CD8+ Tcells from pediatricEBV seronegative HTx patients is feasible, but EBV-Ag pre-sentation by DC may require IL-27 in addition to IL-12 topromote Tc1 cells from naive CD8+ T cell precursors ex vivo.

doi:10.1016/j.clim.2007.03.138

Su.100 Pharmacodynamic Controlled Tapering ofCyclosporine A: A New Step Towards IndividualizedImmunosuppressive Therapy in Transplanted PatientsThomas Giese, Group Leader, Institute of Immunology,Heidelberg, Germany, Claudia Sommerer, Physician,

S174 Abstracts