Direct evidence for the involvement of T suppressor cells in the expression of low-dose paralysis to type III pneumococcal polysaccharide.

Prior treatment (priming) with a subimmunogenic dose of type III pneumococcal polysaccharide results in the development of an antigen-specific state of unresponsiveness termed low-dose paralysis. Such unresponsiveness can be transferred by spleen cells obtained from mice within 5 to 24 hr after priming; the suppressive activity of transferred cells is abolished by treatment with monoclonal anti-Thy-1.2 antibody and complement. These findings show clearly that low-dose paralysis is mediated by T suppressor cells.