T-CELL PRIMING AGAINST ENVIRONMENTAL ALLERGENS IN HUMAN NEONATES - SEQUENTIAL DELETION OF FOOD ANTIGEN REACTIVITY DURING INFANCY WITH CONCOMITANT EXPANSION OF RESPONSES TO UBIQUITOUS INHALANT ALLERGENS

The study below comprises prospective analysis of patterns of allergen -specific T-cell reactivity in a cohort of 23 children bled at regular intervals from 6-10 weeks to 2 years of age, together with cross sect ional studies on panels of cord and adult blood samples. The results i ndicate reciprocal patterns of responses to dietary and inhalant aller gens, the former being frequent in infancy but rare in adults, whereas the latter are preserved and expand between infancy and adulthood. Th ese findings are consistent with a recently proposed model for the dev elopment of immunity to environmental allergens which involves allerge n-driven T-cell ''selection'' during early life leading to deletion of food allergen-specific T-cells via the induction of specific anergy, with concomitant selection and ultimately expansion of mutually exclus ive TH-1-like or TH-2-like reactivity to inhalant allergens via Immune Deviation mechanisms.