Specific inhibition of mRNA accumulation for lymphokines in human T cell line Jurkat by mycobacterial lipoarabinomannan antigen

Abstract

The immunomodulatory effect of Mycobucterium tuberculosis‐derived lipoarabinomannan (LAM) on mitogen/antigen‐induced expression of mRNAs for a number of cytokines in human monocytic cell line Mono‐Mac‐6 and in T cell line Jurkat was investigated. Interestingly, LAM exhibited a down‐regulatory effect on the accumulation of mRNAs for IL‐2, IL‐3, granulocyle‐macrophage colony‐stimulating factor (GM‐CSF), and IL‐2 receptor alpha (IL‐2Rα) in T cells co‐stimulated with phytohacmagglutinin‐P (PHA) and 4β‐phorbol‐12‐myristyl‐13‐acctatc (PMA). In human Mono‐Mac‐6 cells, LAM has a weak inhibitory effect on the lipopolysaccharide (LPS)‐induced mRNA accumulation for IL‐1β, a slight stimulatory effect on mRNAs accumulation for IL‐8 and tumour necrosis factor‐alpha (TNF‐α). but clearly no effect on mRNA accumulation for intercellular adhesion molecule‐1 (ICAM‐I). These findings imply that LAM may contribute to the immunologic defects associated with a number of mycobacterial infections by modulating these mediators. Copyright © 1992, Wiley Blackwell. All rights reserved