Docuil de s ofCD28- cells.TAUBorthwick NJ;Bofill;Gombert W;AkbarAN;Med a E;Sagawa K;LipmanMC;JohnsMA;JanossyG;DepartofCl icl Immology, Royl FreeHospitl andScol;ofMed c e, Ld, UK.SOAIDS19Apr;8(4):431-41U iquIdifier :AIDSLINEMED/2804ABOBJECVESANDDESIGN:Thexpressofthcessorymol ul CD28 wascomparedrus populs of and aturl killer (NK) cells fromH- egve andH-posve d viduals andcorreledwithusgmitoges itro.METHODS:Mulparater flowcotrc analyssusgcomb as ofCD3CD28 andothr markrs wasprformedtogethr with absolucellcouigprphrl blood.Blstransformandprolifrve respses wre also quaitedusgthCorbsoluafter simul with phohaemgglu in(PHA)andai-CD3.CD28-cells wre also purifiedtoco irmthobsrs. RESULTS:InH- egve d viduals >0% ofCD3+cells wre CD28+andrespdedtosimul, whil CD3-CD16+CD57+NK-likecells wre CD28-andfail dtorespd.InH-posved viduals thexpressofCD28 was grelyreduc dandthproportofCD3+CD28- cellsexpanded.CD8 losswas cusedirelybythcumul ofCD28- cellsandmanyofthsexpress damarkrs human leaige-DR,CD38 andCD45ROthir membrane andmol ul s such asAandprfor,ssoc edwithcoltc f,thir coplsm.Thstrogposve correl(r =.66)betweth lack ofCD28 expressandth poorprolifrfromH-posve d viduals was co irmedbydemstrgthaonlyCD28+cellstransformedtolblssandprolifred.AlughthCD28-cludgCD3+cellstransilyexpress dCD25(trl uki-2R ala),thydd otundergoblsogeessoramesuredbybromodeoxyuriduptkeanddiedafter 3-days ulture.Ths obsrs wre co irmedincosimul exprs with ai-CD2andai-CD28.CONCLUSION:InH Doa dCD3+CD28- cellscumule bu areunrespsve tomitoges andai-CD28.Ths cellsppartoreprestrm allydffri deffcorcells which failtorespdtofrthr simulibecuseofthbsceofaCD28 scdsg al.EAdultAiges,CD28/*IMMUNOLOGYFlowCotryHuman HI Dos/*IMMUNOLOGY*H Killer Cells,Naturl/IMMUNOLOGY*TransformMe