INVARIANCE AND RESTRICTION TOWARD A LIMITED SET OF SELF-ANTIGENS CHARACTERIZE NEONATAL IGM ANTIBODY REPERTOIRES AND PREVAIL IN AUTOREACTIVE REPERTOIRES OF HEALTHY-ADULTS

Analysis of the reactivity of IgM with self-antigens in tissues by a quantitative immunoblotting technique showed striking invariance among newborns in the human and in the mouse, The self-reactive repertoire of IgM of adults was also markedly conserved; it comprised most anti-self reactivities that prevailed among neonates. Multivariate analysis confirmed the homogeneity of IgM repertoires of neonates toward self- and non-self-antigens, Multivariate analysis discriminated between newborn and adult repertoires for reactivity with two of five sources of self-proteins and with non-self-antigens. Our observations support the concept that naturally activated B lymphocytes are selected early in development and throughout life for reactivity with a restricted set of self-antigens.