RESUMO
The study objective was to find if serum specific suppressive activities on Lymphocyte transformation in response to Schistosoma mansoni [S. mansoni] antigens, usually present in serum of chronic S. mansoni infected patients, are permeable through the placenta from S. mansoni infected mothers to their newborns. Also, to find if such transferred activities are maintained during breast feeding and after weaning. Control group of 8 normal mothers and their offspring and 3 study groups of 13, 11, 11 S. mansoni infected mothers and their newborns, breast-fed infants and weaned children were included in the study. Proliferative response of Lymphocytes, from S. mansoni donors, to S. mansoni soluble egg antigen [SEA] and adult worm antigen [AWA], in presence of serum from each infected mothers groups, showed significantly higher suppressive activity than when the same lymphocytes were incubated with the same antigens in presence of serum from normal mothers group. This suppressive activity was transferred from S. mansoni infected mothers to their newborns' serum and maintained in their barest-fed infants' serum as donors' lymphocytes showed significantly higher suppressive activity in presence of serum from these two groups than in presence of serum from offspring of normal mothers. Serum from weaned children of S. mansoni infected mothers still showed suppressive activity significantly higher than serum from offspring of normal mothers but significantly lower than suppressive activity of serum from newborns and breast-fed infants of S. mansoni infected mothers. No significant difference in suppressive activity in presence of serum from different groups when donors' lymphocytes were stimulated by PHA indicating that this transferred suppressive activity is specific to S. mansoni antigens. Interleukin-10 [IL-10] production by donors' lymphocytes when stimulated by different stimulants showed results parallel to suppressive activity. Also, IL-10 production by donors' lymphocytes when stimulated by SEA and AWA in presence of serum from offspring of S. mansoni infected mothers showed highly significant positive correlation with suppressive activity of donors' lymphocytes when stimulated by the same antigens in presence of the same serum [P = 0.001 and < 0.001 respectively]. The parallelism and correlation between effect of serum on suppressive activity and IL-10 production suggest that IL-10 production is one of the main mechanisms by which serum affect lymphocytes transformation. These results suggest that the antischistosomal immunological status of S. mansoni infected mothers affects the future of their offspring when infected with S. mansoni and encourage studying the use of effective pathology modulating vaccines with mothers during pregnancy and lactation