Surface Markers on Human B and T Lymphocytes: VII. Rosette Formation Between Peripheral T Lymphocytes and Lymphoblastoid B‐Cell Lines

Almost 100% of peripheral T lymphocytes are shown to have the capacity to form rosettes with human lymphoblastoid B‐cell lines, predominantly at 4°C and with lines having surface‐bound IgG. Blast‐transformed T cells retained this capacity and formed rosettes even at 37°C Unstimulated T cells bound less readily to B‐cell blasts, stimulated by pokeweed mitogen for 72 hr. Even though rosettes, formed at 4°C, were stable for several hours at 72°C, no T‐cell‐mediated cytotoxicity could be detected during overnight incubation. Extreme pH values and trypsinization decreased rosette formation, whereas neuraminidase treatment enhanced the reaction. Rosette formation was independent of bivalent cations and unimpaired in the presence of inhibitors (NaF. NaN₃), undiluted human or fetal call sera, protein A, sonicated sheep erythrocyte membranes, and normal or heat‐aggregated human IgG. Anti‐Ig, anti β₂‐microglobulin, or anti‐T cell sera did not influence rosette formation.