The role of accessory cells in polyclonal T cell activation II. Induction of interleukin 2 responsiveness requires cell‐cell contact

摘要

AbstractIt has previously been reported (Hünig, T. et al.,Eur. J. Immunol.1983.13: 1) that highly purified peripheral T cells do not respond to concanavalin A (Con A) even in the presence of Con A‐induced spleen cell supernatant as a source of interleukin 2 (IL2). In the present report, the hypothesis was tested whether this unresponsiveness correlates with the observed inability of Con A to mediate cell‐cell contact between highly purified T cells. It was found that T cells, pretreated with neuraminidase to reduce their net negative charge, were both aggregated and rendered IL2‐reactive by Con A. In addition, leukoagglutinin (LA) was found to be able to both agglutinate untreated T cells and to make them IL2‐reactive. Neuraminidase treatment reduced the concentration of LA required to mediate both effects. Neuraminidase treatment did not alter the overall Con A‐binding capacity of T cells, nor did it induce reactivity to IL2 in the absence of lectin. Furthermore, irradiated, neuraminidase‐treated T cells served as accessory cells (AC) in the induction of responsiveness to IL2, but not for production of IL2, which depends on Ia+AC. Finally, Lyt‐2−neuraminidasetreated peripheral T cells responded in the same fashion as whole T cell populations, indicating that at least some T cells of the helper phenotype need not interact with Ia+AC for the induction of IL