Immunoglobulin production of neonate--T lymphocyte subset and production of cytokine

On the mechanism underlying the repression of antibody production encountered in the new-born, in this study we used the induction of antibody-producing cells on mitogen stimulation of PWM and SAC, identification of T-cell subsets through two-color FACS and the evaluation of cytokine production of IL-1, IL-2 and BCGF with the following results; 1. The cord blood IgG level rose with gestational weeks due to active transport from the mother. The IgM level was low in full term infants. A natural antibody first appeared in the 16th week. 2. Antibody production on mitogen stimulation in infants was remarkably less than in adults. The inability to produce antibodies appears to be closely related to T-cell factors. 3. In examination of the cell surface maker, new-born infants show less suppressor T-cell but significantly more suppressor inducer T-cell than in adults and that its much smaller number of helper T-cells are insufficient for antibody production. 4. Production of IL-1 in full term infants was significantly lower and that in premature subjects was much lower than that in adults. In full term infants, IL-2 was about the same as in adults, and BCGF production was greater than in adults not depressed in full term infants, and were significantly higher in premature infants than that in adults.