The Effect of DEAE-Dextran on Stimulated Human Lymphocytes, with and without “Exogenous” RNA

Abstract

Diethylaminoethyl dextran (DEAE-Dextran) is a positively charged, long-chain carbohydrate molecule, which has been shown to combine with RNA and to markedly increase the incorporation of RNA into cells. Pagano and co-workers have shown that the addition of DEAE-Dextran to a tissue culture system increased the incorporation of polio virus RNA into cells 100,000 times [1], The life span of animals challenged with Ehrlich ascites tumour can be prolonged, as shown from experiments in this laboratory, when DEAE-Dextran is used in the delivery system with “tumour immune” RNA—spleen cell transfers, to a point comparable with actively immunized animals similarly challenged [2]. DEAE-Dextran will also increase the transferability of a mammalian RNA in transplantation immunity at least 1,000 times, using a system of skin allograft rejection, with improvement to the second set time by transfer of “immune” RNA [3]. DEAE-Dextran will increase the stimulation of interferon production when combined with various RNA’s including Poly I: C., though no specificity of action has been described in this system [4]. Thorling and Larsen have shown an inhibitory effect of DEAE-Dextran on tumour growth in several animal systems both in vivo and in vitro and with reversal by Dextran [5].