The Early Stimulation of Protein Synthesis in Sensitized Guinea Pig Lymph Node Cells by Antigen

Lymph node cells from immunized guinea pigs were studied in short-term cell culture to determine the effect of specific antigen on protein and RNA synthesis. Both RNA and protein synthesis were stimulated early after the addition of antigen to these cultures. Pulse-labeling techniques disclosed a stimulatory effect on protein synthesis by antigen as early as 4 hr after its addition. This stimulatory effect was associated with the specific release of a soluble non-dialyzable mediator which recruited nonsensitized cells to increase their rate of protein synthesis. The stimulatory effect of antigen on protein synthesis was abolished by the prior addition of actinomycin D.