Synthesis of Specific RNA Molecules during Immune Response in the Mouse Spleen

[摘要] Purified RNA was prepared from the spleens and lungs of uninjected mice and of mice injected with S. typhi , sheep red blood cells (SRBC) or syngeneic mouse red blood cells (MRBC). Quantitative and qualitative changes in RNA synthesis were studied.The specific radioactivity of pulse-labeled RNA in the spleens of mice injected with S. typhi was highest at about 72 hr in the primary response and at 24 to 30 hr in the secondary response. The corresponding responses to SRBC injection were somewhat later. The rate of labeling of lung RNA from immune mice did not show significant fluctuation. Analysis by sucrose density gradients showed that pulse-labeled immune spleen RNA contained a higher proportion of RNA molecules of greater than 28 S than was present in normal spleen RNA.Qualitative changes in RNA populations were studied by comparing the competition of various RNA preparations for hybridization with DNA. The injections of any of the three agents, S. typhi , SRBC or MRBC, induced the formation of some spleen RNA populations differing from normal RNA. This nonspecific change was similar for the three agents. In addition, some specific changes were observed in response to the two antigens. The new species of RNA molecules appeared 24 hr following injection of S. typhi , but not until 60 hr after SRBC injection. The significance of these “antigen specific” RNA changes is discussed with respect to antibody specificity and overall physiologic response.

[学科分类] 生物科学（综合）