Enzymatic Inactivation of Immunologically Competent Lymph Node Cells in the “Transfer Reaction”

Abstract

Summary: Skin from New Zealand rabbits was implanted subcutaneously into Dutch rabbits in pairs. The lymph node cells from sensitized Dutch rabbit were incubated with and without inactivated ribonuclease for varying time periods and the intradermal injections of these cells into the specific New Zealand skin donor produced intense transfer reactions. Incubation of sensitized cells with 4 mg or 0.4 mg of ribonuclease inhibited the transfer reaction to differing degrees, depending on length of incubation, number of cells and concentrations of ribonuclease used. The effect of enzyme on sensitized lymph node cells could be partially blocked by addition of ribonucleic acid to the incubation mixture, or by pretreatment of ribonuclease with rabbit antiribonuclease serum. The viability of sensitized cells, as measured by trypan blue method and by survival in Millipore diffusion chambers, was unaffected by the concentrations of ribonuclease used in the experiment. Moreover, cells treated with active enzyme regained their ability to produce transfer reaction after cultured in diffusion chamber. It was concluded that an intact protein synthesis of sensitized lymph node cells is essential for the expression of the transfer reaction.