Evidence for double stranded RNA region in macrophage antigen-binding RNP

Peritoneal macrophages contain a ribonucleoprotein (RNP) which is unique to this cell type. Upon exposre of macrophages to antigens, fragments of the antigens are found to be associated with the RNP molecule. In this report, we provide evidence that the RNP molecule contains a double stranded RNA component. The RNP moiety can be degraded by treatment with a combination of ribonucleases A, T 1 and III followed by heating. It is suggested that both the polypeptide component and the double stranded RNA component of the complex contribute to the resistance of the complex to ribonucleases.