T cell receptor y5bearing cells aredecreased intheperipheral bloodofpatients withatopic diseases

SUMMARY Thebiological roleofT cell receptor(TCR)ybbearing cells iscurrently notfully understood. Recently, a monoclonal antibody (TCR61)reacting against thewholemolecule becameavailable whichfacilitates thedirect analysis ofTCR-yb+cells. We studied I 1 children withatopic dermatitis, 20children withatopic asthma, 18adults withatopic dermatitis and38healthy agematched controls aged4-51years.Lymphocytes were isolated fromheparinized peripheral bloodandtheproportion ofTCR-yb+lymphocytes was determined byFACSanalysis. Patients withatopic diseases yielded a significantly (P< 0-01) lower proportion ofTCR-yb+cells compared withnormalcontrols (median 4-8%versus7-1%). Thepercentage ofTCR-yb+cells showed an age-dependent decline inboththe patient group(r = -049,P< 00l1) andthecontrol group (r=-040,P< 001).Inaddition, the proportion ofcells whichexpressed CD8,TCR-yborCD4,TCR-ybsimultaneously was determined bydouble labelling immunofluorescence. Whereas CD4+,TCR-yb+cells could beidentified inonly a fewindividuals, CD8+,TCR-yb+cells were foundinnearly allcontrols (median 2-4%, range0-010-8%); atopic patients displayed significantly (P<0-01) lower proportions ofCD8+,TCR-yb+cells.