Control of mitogen-induced transformation: Characterization of a splenic suppressor cell and its mode of action

Abstract

The present study demonstrates that mouse spleen cells contain a population of glass wool adherent T lymphocytes which exhibit the capacity to suppress non-glass adherent lymphocyte responses to mitogens. These suppressor cells are stimulated by both low and high doses of PHA 1 1 Abbreviations used: Act. D, actinomycin D; ATS, anti-thymocyte antisera; C′, guinea pig complement; con A, concanavalin A; Bu 2cAMP, dibutyryl cyclic 3′,5′-adenosine monophosphate; HBSS, Hank's basic salt solution; GAL, glass-adherent lymphocytes; NAL, non-glass adherent lymphocytes; PHA, phytohemagglutinin; Mit. C, mitomycin C; [ 3H] Tdr, [ 3H]thymidine; MEM, minimum essential medium; FCS, fetal calf serum. and high doses of con A. The suppressor cell effect is observed when UNA, but not RNA or protein synthesis, is studied. This glass-adherent suppressor cell population is characterized as being the primary DNA synthesizing cells during the early (0–8 hr) stages of culture. Suppression still occurs when the suppressor cells are treated with mitomycin C, actinomycin D or cycloheximide. This implies that new macromolecular synthesis may not be required for suppression to occur. Suppression is blocked by inhibiting synthesis of prostaglandin and is mimicked by Bu 2cAMP. This suggests that mitogen activated suppressor cells regulate T cell responses via production of prostaglandin which modulates the concentration of intracellular cyclic nucleotide levels.