title: Identification of the mycobacterial subcomponents involved in the release of tumor necrosis factor-related apoptosis-inducing ligand from human neutrophils.
abstract: Intravesical administration of Mycobacterium bovis bacillus Calmette-Guérin (BCG) continues to be a successful immunotherapy for superficial bladder cancer. Recently, workers in our laboratory observed expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on neutrophils in voided urine following BCG therapy. Neutrophils released a soluble and functional form of TRAIL when they were stimulated in vitro with BCG, and the activity was localized predominantly to the cell wall fraction. In this study, we examined the ability of individual mycobacterial components to stimulate TRAIL release from neutrophils. Our results demonstrated that cell wall-derived lipoarabinomannan (LAM), mycolyl arabinogalactan-peptidoglycan complex, and a Triton X-114 (Tx114)-solubilized protein pool were effective agonists of TRAIL release from neutrophils. Mycobacterial DNA was also an agonist of TRAIL release from neutrophils. Furthermore, purified antigen 85 ABC complex and alpha-crystallin (HspX), two major cell wall antigens present in the Tx114 pool, induced TRAIL release from neutrophils. The Tx114 pool stimulated HEK-293 cells expressing either Toll-like receptor 2/1 (TLR2/1) or TLR2/6, but only HspX was able to stimulate TLR2/6-expressing cells. TLR4/MD2/CD14-expressing cells responded only to LAM. Collectively, these results suggested that TRAIL release from neutrophils was induced through the recognition of multiple mycobacterial components by TLR2 and TLR4.
authors.affiliation: Department of Urology, 3204 MERF, University of Iowa, 375 Newton Road, Iowa City, IA 52242-1089, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Simons
authors.forename: Jill M
authors.initials: JM
authors.lastname: Moore
authors.forename: Troy J
authors.initials: TJ
authors.lastname: Kemp
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Griffith
mesh_terms: D002460:Cell Line; D006801:Humans; D016898:Interferon-alpha / Q000502:physiology; D009163:Mycobacterium bovis / Q000737:chemistry / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology*; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000378:metabolism*; D051195:Toll-Like Receptor 2 / Q000819:agonists / Q000096:biosynthesis / Q000502:physiology; D051197:Toll-Like Receptor 4 / Q000819:agonists / Q000096:biosynthesis / Q000502:physiology
chemical_list: D016898:Interferon-alpha; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4