The Regulation of Resistance to Schistosoma mansoni by a Soluble α/β TCR Analog, Produced by a Cloned T Cell Hybridoma

Immunity to Schistosoma mansoni is regulated by an auto-anti-idiotypic network. The T cells in this network interact through soluble regulatory factors. These studies describe a soluble suppressor-inducer factor (TsiF) derived from TCR+ suppressor-inducer clone Q37, Q37 is the fusion product of CD4+ T cells derived from S. mansoni-infected mice and TCR-, BW1100 thymoma cells. [35S]Methionine biosynthetically labeled TsiF was immunoprecipitated with mAb H57-597 (anti-pan α/β TCR) and adsorbed with protein G-agarose. The eluted 72-kDa TCR analog was reduced with dithiothreitol. Components of 32 and 44 kDa were found on SDSPAGE. These components were analogous to the α and β chains of the TCR, binding antigen, or expressing Vβ determinants, respectively. TsiF suppressed delayed-type hypersensitivity to S. mansoni antigens in a genetically and antigenically restricted manner. TsiF totally abrogated protective immune response against S. mansoni. These soluble TCR analogs may idiotypically regulate the resistance to S mansoni. Q37 is an appropriate source of a suppressor TCR analog for the molecular analyses of this idiotypic regulation.