S115Abstracts

METHODS:Peripheral blood mononuclear cells (PBMCs) wereisolated from a cohort of adult patients with 22qdel (ages 15-48) and controls (ages 20 to 78). PBMCs were incubated forfive hours at 37° C in RPMI after stimulation with either PMA5 ng/ml, ionomycin 500 ng/ml, and GolgiPlug 1 μl/ml (for IL-4 and IFN-γ staining); PMA 50 ng/ml, ionomycin 1 μg/ml andGolgiStop 1.5 μl/ml (for IL-17 staining); or GolgiPlug 1 μl/ml(control). PBMCs were stained with surface antibodiesagainst CD3 and CD4 and intracellular antibodies against IL-4, IFN-γ, and IL-17 and analyzed by flow cytometry.Statistical analysis was performed using the Mann-Whitneytest.RESULTS:There was a significantly elevated percentageof CD3+CD4+IL-4+ IFN-γ- lymphocytes in 22qdel patientscompared to controls (2.21% vs 1.09%, pb0.01). There was nosignificant difference in the percentage of CD3+CD4+IL-4-IFN-γ+ or CD3+CD4+IL-17+ lymphocytes in 22qdel patientscompared to controls (14.48% vs 11.68%, p=0.15 and 1.60% vs1.35%, p=0.44).CONCLUSIONS:22qdel patients had a higherpercentage of IL-4+CD4+ T-cells than controls consistent witha skewing towards a Th2 phenotype. This is consistent withthe clinical observation of increased atopic manifestations in22qdel patients and could be due to a skewing of T-cellsubsets during homeostatic proliferation.

doi:10.1016/j.clim.2009.03.337

F.80. The TransmembraneE3 Ligase, GRAILUbiquitinates and Degrades CD83 on CD4+ T cellsLeon Su, Hideyuki Iwai, Jack Lin, C. Garrison Fathman.Stanford University, Stanford, CA

Ubiquitination of eukaryotic proteins regulates a broadrange of cellular processes including T cell activation andtolerance. We have previously demonstrated that GRAIL, atransmembrane RING finger ubiquitin E3 ligase, is required forthe induction of T cell anergy. In this study, we show thatGRAIL can down modulate the expression of CD83, predomi-nantly described as a cell surface marker for mature dendriticcells, on CD4 T cells. GRAIL mediated down modulation ofCD83 is dependent on an intact GRAIL extracellular proteaseassociated (PA) domain and an enzymatically active cytosolicRING domain, and proceeds via an ubiquitin-dependent 26Sproteosome pathway. Furthermore, ubiquitin modification oflysine residues at position K168 and K183, but not K192 in thecytoplasmic tail of CD83 was shown to be necessary fordegradation of CD83. This study defines a unique mechanismof ubiquitination by a transmembrane RING E3 ligase, andidentifies CD83 as a new E3 substrate of GRAIL.

doi:10.1016/j.clim.2009.03.338

F.81. Regulatory T Cells in Pediatric RenalTransplant RecipientsJames Tong, Qizhi Tang, Paul Brakeman, Peter Stock.University of California at San Francisco, San Francisco, CA

Regulatory T cells (Tregs) are a subset of T cells that arehypoproliferative and can modulate the action of effector Tcells (Teff). In humans, this subset of Tcells represents 1-2% of

all Tcells and 5-10% of all CD4+ Tcells. Because of their abilityto suppress Teff, there has been increasingly more interest intheir role in autoimmunity and transplantation where thebalance of Teff overwhelmingly outweighs Tregs. NaturalTregs are defined as CD4+CD25+Foxp3+T cells. We used FACSanalysis of peripheral blood to profile T cells in a retro-spective cohort of pediatric renal transplant undergoingstandard immunosuppression of daclizumab, tacrolimus,mycophenolate mofetil, and steroids. We hypothesized thatat one year post transplantation, pediatric renal transplantrecipients without any episodes of acute cellular or humoralrejection would have higher percentages of natural Tregsamong CD4+ Tcells compared with those recipients who havehad previous episodes of rejection. At 12 months posttransplantation, rejection free patients had 6.8% (SD=1.8%,n = 10) Tregs in their peripheral blood compared to 3.17%(SD=0.4%, n=5) Tregs in thosewho had at least one episode ofrejection (p=0.0008). This result shows that pediatric kidneytransplant recipients who are rejection free have similarpercentages of Tregs compared to healthy controls and havesignificantly increased percentages of Tregs compared tothose with prior episodes of rejection. This data, ifconfirmed, could be a marker for those patients who maytolerate reduction in immunosuppression.

doi:10.1016/j.clim.2009.03.339

F.82. Modulation of T Cell Unit in PersistentRecurrent Herpes Virus InfectionsMichael Rudenko1, Andrey Simbirtsev2, Irene Rudenko1,Andrey Zabelev2, Andrey Shemshura3. 1Clinical CenterEuroDon, Rostov-on-Don, Russia; 2State Research Instituteof Highly Pure Biopreparations, Saint Petersburg, Russia;3Parasitology, Rostov-on-Don, Russia

With the aim to prove the efficacy of the new patentedscheme of treatment in acute phase of persistent recurrentherpes virus infections a prospective blinded placebocontrolled cohort study was designed. 800 patients in acutephase of herpes virus infection were randomly recruited intotwo arms. The age distribution was 24-32 y.o. -43%, 33-42 y.o.-32%, 42-49 y.o. -25%, 43% of themweremen and 57 - women.No significant bias was found between arms. Patients in thefirst arm (n=400) received immune adjuvant D-glutaminil-L-tryptophan according to patented scheme: intranasally100 μg daily, valacyclovir 500 mg per os and penciclovirlocally during 10 days (priority patent certificate for themethod of treatment #2008113617/14(014798) from11.04.2008). Patients in the second arm received placeboand the same antiviral treatment as in arm one. Eachpatient underwent careful immune examination: {(PCR(blood, saliva, vesicles), ELISA (IgG, IgM, cytokines), flowcytometry (CD3+; CD4+; CD8+; CD16+; CD3+,CD25+; CD3+,CD95+; CD3+,HLADR+; CD20+)), assessment of phagocytosis,immunoglobulins A, M, G, circulating immune complexes}.After the treatment in the first arm immune deviations ofT-cell unit were optimized: T-cells were increased (64.08±5.88 vs. 77.7±8.58: before vs. after treatment) NK cells(10.38±4.68 vs 13.74±4.72), markers of late negativeactivation of T cells decreased (8.22±4.27vs. 5.21±4.18),