FUNCTIONAL ASSESSMENT OF CD2, CD3 AND CD28 ON THE SURFACE OF PERIPHERAL-BLOOD T-CELLS FROM INFANTS AT LOW VERSUS HIGH GENETIC RISK FOR ATOPY

Recent studies from several laboratories suggest that the rate of post natal maturation of T-cell function(s) associated with in vitro activa tion may be slower in children at high genetic risk for atopy (HR), co mpared to their normal (low risk; LR) counterparts. The present study compared the in vitro activity of the function-associated surface mole cules CD2, CD3 and CD28 in panels of 27 HR and 13 LR infants, with a r eference panel of 10 adults, employing assay systems involving T-cell stimulation with MoAbs against these molecules. The response maxima in duced by saturating levels of the MoAbs were equivalent in all 3 group s, but T-cells from the HR infants required 10-50 fold higher levels o f anti-CD3 stimulation to attain their maximum response, relative to a dults (p=0.02); T-cells from LR infants were also less responsive to a nti-CD3 than adults, but these differences were smaller and did not at tain statistical significance. It is suggested that these differences are attributable to varying proportions of competent T-memory cells (w hich respond to low levels of anti-CD3) in PBL from these populations, the postnatal accumulation of which proceeds slowest in the HR group.