title: Role of PGL-I of M. leprae in TNF-alpha production by in vitro whole blood assay.
abstract: Phenolic glycolipid-I (PGL-I) is known to be a major antigen of Mycobacterium leprae. We have studied the influence of PGL-I on the production of Tumour Necrosis Factor alpha (TNF-alpha) using the in vitro whole blood assay. Armadillo-derived M. leprae (ADML) are thought to be depleted of PGL-I during the purification process. M. leprae obtained from mouse foot pad material (MFPML) has been subjected to a less rigorous purification process; their PGL-I coating is therefore believed to be more intact than that of ADML. PGL-I or ADML alone induced the secretion of minimal levels of TNF-alpha in whole blood assay; when added in combination, higher levels of this cytokine were observed. The highest TNF-alpha response was seen following stimulation with MFPML. MFP material not infected with ML did not elicit any response. The difference in TNF-alpha response shown by ADML and MFPML was postulated to be largely due to the presence of higher levels of PGL-I in MFPML. This increase in TNF-alpha production suggests that PGL-I may play a significant role in the induction of TNF-alpha during natural infection.
authors.affiliation: Leprosy Mission Nepal, Anandaban Hospital, Kathmandu, Nepal.
authors.forename: S
authors.initials: S
authors.lastname: Dhungel
authors.forename: C
authors.initials: C
authors.lastname: Ranjit
authors.forename: B R
authors.initials: BR
authors.lastname: Sapkota
authors.forename: M
authors.initials: M
authors.lastname: Macdonald
mesh_terms: D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000494:pharmacology*; D001773:Blood Cells / Q000378:metabolism*; D006017:Glycolipids / Q000494:pharmacology*; D006801:Humans; D007918:Leprosy / Q000378:metabolism; D008297:Male; D009166:Mycobacterium leprae; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis* / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D006017:Glycolipids; D014409:Tumor Necrosis Factor-alpha; C045169:phenolic glycolipid I, Mycobacterium leprae