FUNCTION AND EXPRESSION OF A HUMAN IDIOTYPIC NETWORK IN SCHISTOSOMIASIS-JAPONICA

The cross-reactive idiotype (Hu-SJ-CRI(M)) is defined by polyclonal hu man anti-idiotypic antibodies derived from chronically S. japonicum in fected patients. The present study shows that serum levels of Hu-SJ-CR I(M) expressed by antibodies to S. japonicum soluble egg antigen (SEA) are associated with acute infection and hepatosplenic disease. Xenoge nic anti-idiotypic antisera (anti-Hu-SJ-CRI(M)) suppressed human lymph ocyte blastogenesis to SEA in vitro by 47-82% (P < 0.05). These anti-i diotypic antibodies also suppressed in vitro granuloma formation induc ed by SEA coated beads in a dose dependent manner. This immunosuppress ion was antigen specific in that mitogen (PHA) or non-related antigen (PPD) induced blastogenic responses were not suppressed. Surprisingly, anti-idiotypic antibodies (anti-SJ-CRI(M)), which describe the mouse correlate CRI(M) were not suppressive in the human blastogenesis or in vitro granuloma formation assays. These data indicate a dichotomy in the function and specificity of the idiotype/anti-idiotype human and m urine immune networks in S. japonicum infection. Thus, only the patien t derived molecules and serology form the basis for an immunoregulator y network in Schistosomiasis japonica.