Characterization of Japanese encephalitis virus-specific suppressor T cells and their product in suppression of the humoral immune response in mice.

Since Japanese encephalitis virus (JEV) induces the generation of suppressor T cells in mouse spleen which, through the production of a soluble suppressor factor (SF), suppress IgM plaque-forming cells (IgM-PFC) the present study was undertaken to further characterize these suppressor cells and the SF. The suppressor cells were Ly1-2+ and sensitive to hydrocortisone and a high dose of irradiation. SF was trypsin-sensitive, thermolabile and non-dialysable, and passed through a 450-nm filter. This SF was shown to be a low molecular weight substance, with an approximate MW of 18,000 daltons.