T cell growth factor abrogates concanavalin A-induced suppressor cell function.
Concanavalin A (Con-A)-induced suppressor T cells were found to respond to T cell growth factor (TCGF) by proliferation. TCGF abrogated the suppressor activity exerted by these cells on phytohemagglutinin (PHA)- and alloantigen- induced lymphocyte proliferation and on pokeweed mitogen (PWM)-driven immunoglobulin secretion. The Con-A-activated suppressor T cells absorbed the TCGF activity, preincubation of these active suppressor cells with TCGF abolished their suppressor activity and addition of increasing numbers of Con-A-activated T cells reverted the abrogator,/ effect of TCGF. Altogether, these findings suggest that Con-A-induced suppressor T cells exert their function by decreasing the available levels of TCGF. Cyclosporin-A (CYA), which is known to inhibit the expression of receptors for TCGF on T cells, also inhibited the suppressor activity as determined in both indicator systems, namely PHA- or alloantigen-induced DNA synthesis and PWM-induced immunoglobulin synthesis. CYA made Con-A-treated T cells unresponsive to TCGF and unable to absorb the growth factor, supporting the notion that CYA inhibits the expression of TCGF receptors on T cells, a mechanism by which this drug seems to abrogate Con-A-induced suppressor T cell function.
D003208:Concanavalin A / Q000494:pharmacology*; D003524:Cyclosporins; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D008222:Lymphokines / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects*; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects* / Q000276:immunology
D003524:Cyclosporins; D007376:Interleukin-2; D008222:Lymphokines; D010456:Peptides, Cyclic; D003208:Concanavalin A