FACTORS AFFECTING CONCANAVALIN A-MEDIATED RED-BLOOD-CELL ABSORPTION TO PHASE-II AND PHASE-III HUMAN-DIPLOID FIBROBLASTS

In order to reveal the age-related change in Con A-mediated RBC adsorption to human diploid fibroblasts, factors affecting the RBC adsorption were investigated. The amount of RBC adsorption was greatly influenced by the incubation time and temperature as well as the Con A concentration. Temperature affected not only the rate but also the extent of RBC adsorption. The amount of RBC adsorption was, however, not changed significantly below a density limit dependent on population doubling levels or during six days after cell inoculation. Phase III cells adsorbed RBCs well with both the RBC coating method (in which Con A-coated RBCs are adsorbed to fibroblasts) and the fibroblast coating method (in which RBCs are adsorbed to Con A-coated fibroblasts). Phase II cells also adsorbed RBCs in a moderate amount with the RBC coating method. However, RBC adsorption to phase II cells with the fibroblast coating method did not occur even at higher Con A concentrations, after prolonged incubations or at higher temperatures. The dispersedly adsorbed RBCs were gathered into clumps and released from cell surfaces when RBC-adsorbed fibroblasts were cultured at 37°C. This process occured effectively even for phase III cells. © 1979.