The effect of temperature-dependent autorosettes on B/T cell ratios of purified rabbit peripheral blood lymphocytes.

Contradictory reports as to B/T cell ratios in the peripheral blood lymphocytes (PBL) of rabbits led to an investigation of current purification methods. PBL prepared by sedimentation at 37 degrees C in gelatin solution showed the same B/T ratios as did whole blood. PBL prepared by the Ficoll-Hypaque method at 4 degrees C or at room temperature were enriched in B cells compared to the whole blood. This enrichment depended on the presence of autologous erythrocytes during centrifugation and it was not demonstrable when centrifugation was carried out at 37 degrees C. Resuspended red cell pellets contained more than 3 times as many rosette-forming cells if the pellets were obtained by centrifugation of blood on Ficoll at 4 degrees C rather than 37 degrees C. We, therefore, conclude that aggregation of T cells with autologous erythrocytes is responsible for the depletion of B cells in the PBL prepared by the Ficoll-Hypaque method at 4 degrees C or at room temperature.