Unresponsiveness of peripheral T cells induced by apoptotic bodies derivedfrom autologous T cells

Several reports described the dose-dependent effect of Staphylococcus aureu s enterotoxin B (SEB) regarding both levels of apoptosis and anergy of T ce lls. We investigated here whether T-cell apoptosis induced with SEE causes unresponsiveness of naive T cells. Apoptotic bodies were isolated from huma n T cells stimulated with antigen-presenting cells (APCs) and SEE by the co ntinuous density gradient centrifugation method. When naive T cells were st imulated with APCs and SEE in the presence of apoptotic bodies, their proli feration was dose dependently suppressed and their TCRs were less downregul ated than those of T cells stimulated without apoptotic bodies. Furthermore , those T cells were predisposed not to respond to restimulation with fresh APCs and SEE in the absence of apoptotic bodies. These results, taken toge ther with the observation of tight binding of apoptotic bodies to APCs, imp ly that T cells stimulated in the presence of apoptotic bodies may undergo unresponsiveness due to interruption of contact with APCs. (C) 1999 Academi c Press.