attempted to elicit cytotoxic T lymphocyte (CTL) responsesagainst an Amyloid-associated antigen in a mouse model.Using a peptide from E6 light chain as a target antigen, weimmunized HLA-A2 transgenicmice. Following immunization,we restimulated splenocytes with peptide ex vivo and testedthe resulting CTL for E-specificity in chromium-release killingassays against a variety of cellular targets. The CTL kill HLA-A2+ targets pulsed with cognate peptide or a closely related‘‘heteroclitic’’ peptide, as well an HLA-A2+ cell line trans-fected with the full length E protein. We used fluorescentpentamers to quantify the percentage of E peptide/ HLA-A2-specific CTL, which was highly variable, from less than 2% togreater than 15% of the CD8+ T-cell population. We concludethat the E6 peptide immunization protocol is effective inmice at eliciting CTL capable of killing target cells bearing theE6 protein or peptide. We propose that this technique beadapted for use in clinical trials to eliminate the bonemarrowplasma cells which produce amyloidogenic light chains.

doi:10.1016/j.clim.2006.04.173

F.134. Increased Population of CD4+CD25highRegulatory T-Cells in the Peripheral Blood of RenalCell Carcinoma Patients.Eyad Elkord,1 Richard Griffiths,2 Dominic Rothwell,2

David Gilham,2 Peter Stern,1 Robert Hawkins.21Immunology, Paterson Institute for Cancer Research,Manchester, United Kingdom; 2Medical Oncology, PatersonInstitute for Cancer Research, Manchester, United Kingdom.

Regulatory T-cells, identified as a sub-population ofperipheral blood lymphocytes co-expressing the cell surfacemarkers CD4 and CD25, are important in maintainingimmune homeostasis. Increased numbers in blood and intumour have been reported in a number of human cancersand this may well be a mechanism by which tolerance totumour-associated antigens occurs. Renal cell carcinoma isan immunogenic tumour that is resistant to most cytotoxicdrugs and occasionally sensitive to immunomodulatorydrugs such as interleukin-2 and interferon-a. We havequantified the percentage of CD3 positive cells co-expres-sing CD4 and high levels of CD25 by flow cytometry. Thispopulation of T-cells has previously been reported toexpress a predominant regulatory phenotype. We haveobserved a higher percentage of CD4+CD25high T-cellswithin the CD3+ fraction of peripheral blood mononuclearcells from previously untreated renal cell cancer patientswhen compared to healthy controls. When this populationof cells are magnetically isolated, they exhibit a stronginhibitory effect on the proliferation of CD4+CD25- respond-er cells and express high levels of the nuclear transcriptionrepressor protein FOXP3, as shown in the figure. Thistranscription factor is a sensitive marker for T-cells withregulatory function and therefore these CD4+CD25high cellsare likely to be true regulatory T-cells rather than activatedCD4 cells. The presence of these cells may contribute to theimmunosuppressed state that occurs in cancer patients andmay also impair tumour rejection following administrationof immunostimulatory drugs. The effectiveness of currentimmunotherapies may be enhanced by the removal of this

subset of T-cells, and methods by which this may beachieved are discussed.

doi:10.1016/j.clim.2006.04.174

F.135. Induction Therapy Is Not Associatedwith Increasing Risk of Cancer After RenalTransplantation.Kais Harzallah,1 Lionel Frimat,2 Michele Kessler,2

Magali Giral,1 Yvon Foucher,1 Jean Paul Soullilou,1

Jacques Dantal.1 1Nephrology, CHU Hotel-Dieu, 30 Bd JeanMonnet, 44093 Nantes, Nantes, France; 2Nephrology,University Hospital of Nancy, Nancy, France.

Several studies reported the deleterious effect of thymo-globulin as risk factor of PTLD after renal transplantation(TX). The aim of our study was to compare thymoglobulin(ATG/ALG) or Interleukin-2 receptor monoclonal antibodies(IL2R Moab) as induction therapy (IT) for the association withincreasing risk of skin or solid tumors. 3512 consecutivekidney recipients at Nantes and Nancy centers from Jan 1980to Feb 2005 were included in the study (older than 18 years).Univariate (UA) and multivariate analysis (MA) was done withCox model. IT with ATG/ALG during a mean course of 10, 4days (1 to 25) was given in 84, 3% and Anti-IL2RMoab in 18, 7%.Maintenance therapy was based on anticalcineurines on allpatients (76, 6% CsA or 23, 4% FK506), on antimetabolites in95, 3% (48, 8%MMF or 51, 2% Azathioprine) and corticosteroids(in 99, 44 %). Acute reject occurred on 21, 6% of cases andwastreated, in addition to steroids pulses, by polyclonal ormonoclonal antibody on 5, 9% of cases. Prevalence of cancerwas 13% (7, 35% solid tumors, 8, 50% skin tumors) occurringrespectively after 67, 8months and 66, 5months. MA retrieveas risk factors of skin cancers: age N50 years on TX (RR:3, 59),male patients (RR:1, 59), multiple warts (RR:2, 06) andantecedents of skin cancers (RR:2, 21). In opposite, diabeticpatients (RR:0, 45) and TX before 1999 (RR:0, 31) wereprotected. Risk factors for solid tumors were:age N50 years(RR:1, 98) and previous skin cancer (RR:1, 66). Negativecorrelation exist with dialysis for a long period N to 5 years(RR: 0, 54) and year of TX before 1999 (RR: 0, 30). The effectof ITwas no significant in UA and MA analysis. Conclusion: Theeffect of ITand or those given for acute rejection therapy wasno significant on occurrence of solid or skin cancer. This issuggest that prolonged immunosuppression is more importantthan short-term immune deregulation.

doi:10.1016/j.clim.2006.04.175

F.136. IL-10 Induction By Latent Membrane Protein1 of Epstein Barr Virus.Stacie Lambert,1,2 Olivia Martinez.1,2 1Department ofSurgery - Transplant, Stanford University School ofMedicine, Stanford, CA; 2Immunology Program, StanfordUniversity School of Medicine, Stanford, CA.

Epstein-Barr virus (EBV) can transform human B lympho-cytes in culture and is associated with some forms of clinicalB-cell lymphoma including post-transplant lymphoprolifera-

AbstractsS98