Effect of Mitogenic Stimulation of Murine Splenocytes on PEG-Induced Cell Fusion

Publisher Website
Google Scholar
Abstract
A cell fusion assay system was devised as a means of measuring cell activation. Polyethylene glycol (PEG) was used to induce fusion between spleen cells of various mouse strains and the BW5147 thymoma cell line. A fusion index (FI) was calculated by determining the ratio of the number of nuclei in fused cells to the number of nuclei in all cells and multiplying by 100 (the FI could range from 0 to 100). Spleen cells from BALB/c mice were compared in PEG-induced fusion assays. BALB/c spleen cells stimulated with phytohemagglutinin, leucoagglutinin, concanavalin A, pokeweed mitogen and LPS showed FI two- to three-fold higher than those found in unstimulated cultures, indicating that stimulated cells fuse at much higher rates. This response is mitogen dose-dependent and parallels DNA synthesis as measured by 3H-TdR incorporation. Treatment of spleen cells with cycloheximide 12 h prior to fusion had no effect on FI. In vivo and in vitro stimulation of BALB/c, C57BL/ 6 and NZW mice with LPS resulted in enhanced FI. This was not the case in low-responder DBA/2 and nonresponder C3H/HeJ animals.
Keywords