02208nas a2200289   4500000000100000008004100001260001300042653002400055653001400079653001600093653001100109653002800120653002500148653002600173653003200199100001400231700001400245700001700259700001800276245013700294856005900431300000900490490000700499050003200506520136600538022001401904       2001                            d  c2001 Mar10aAntigens, Bacterial10aCell Line10aGlycolipids10aHumans10aLeukocytes, Mononuclear10aMycobacterium leprae10aTumor Cells, Cultured10aTumor Necrosis Factor-alpha1 aCharlab R1 aSarno E N1 aChatterjee D1 aPessolani M C00aEffect of unique Mycobacterium leprae phenolic glycolipid-I (PGL-I) on tumour necrosis factor production by human mononuclear cells.  uhttp://leprev.ilsl.br/pdfs/2001/v72n1/pdf/v72n1a10.pdf  a63-90 v72  aInfolep Library - available3 a<p>Mycobacterium leprae cell wall-associated components are found in large amounts in the tissues of leprosy patients, particularly those at the lepromatous pole. Among these molecules, the phenolic glycolipid-I (PGL-I), unique to M. leprae, has been involved in the selective anergy observed in the lepromatous patients. Armadillo-derived M. leprae retains only a small proportion of the total PGL-I found in infected tissues. Therefore, the addition of PGL-I to M. leprae in vitro is important for a better understanding of M. leprae effects in vivo. We have studied the influence of PGL-I on TNF production by normal human peripheral blood mononuclear cells (PBMC) and by a human monocytic leukaemia cell line (THP-1) following stimulation with killed M. leprae. PGL-I alone did not induce TNF secretion by PBMC, but when associated with a sub-optimal dose of armadillo-derived M. leprae increased the release of this cytokine. In agreement with these results, M. leprae-exposed THP-1 cells did not secrete detectable levels of TNF unless PGL-I was simultaneously added to the culture. This increase in TNF production suggests that PGL-I plays a role in the induction of TNF during the natural infection. In addition, the modulatory effect of PGL-I on TNF release by THP-1 cells reinforces that monocytes are one of the possible targets of this molecule.</p>  a0305-7518