title: Interaction of Mycobacterium leprae with human airway epithelial cells: adherence, entry, survival, and identification of potential adhesins by surface proteome analysis.
abstract: This study examined the in vitro interaction between Mycobacterium leprae, the causative agent of leprosy, and human alveolar and nasal epithelial cells, demonstrating that M. leprae can enter both cell types and that both are capable of sustaining bacterial survival. Moreover, delivery of M. leprae to the nasal septum of mice resulted in macrophage and epithelial cell infection in the lung tissue, sustaining the idea that the airways constitute an important M. leprae entry route into the human body. Since critical aspects in understanding the mechanisms of infection are the identification and characterization of the adhesins involved in pathogen-host cell interaction, the nude mouse-derived M. leprae cell surface-exposed proteome was studied to uncover potentially relevant adhesin candidates. A total of 279 cell surface-exposed proteins were identified based on selective biotinylation, streptavidin-affinity purification, and shotgun mass spectrometry; 11 of those proteins have been previously described as potential adhesins. In vitro assays with the recombinant forms of the histone-like protein (Hlp) and the heparin-binding hemagglutinin (HBHA), considered to be major mycobacterial adhesins, confirmed their capacity to promote bacterial attachment to epithelial cells. Taking our data together, they suggest that the airway epithelium may act as a reservoir and/or portal of entry for M. leprae in humans. Moreover, our report sheds light on the potentially critical adhesins involved in M. leprae-epithelial cell interaction that may be useful in designing more effective tools for leprosy control.
authors.affiliation: Laboratory of Cellular Microbiology, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, RJ, Brazil.
authors.forename: Carlos A M
authors.initials: CA
authors.lastname: Silva
authors.forename: Lia
authors.initials: L
authors.lastname: Danelishvili
authors.forename: Michael
authors.initials: M
authors.lastname: McNamara
authors.forename: Márcia
authors.initials: M
authors.lastname: Berredo-Pinho
authors.forename: Robert
authors.initials: R
authors.lastname: Bildfell
authors.forename: Franck
authors.initials: F
authors.lastname: Biet
authors.forename: Luciana S
authors.initials: LS
authors.lastname: Rodrigues
authors.forename: Albanita V
authors.initials: AV
authors.lastname: Oliveira
authors.forename: Luiz E
authors.initials: LE
authors.lastname: Bermudez
authors.forename: Maria C V
authors.initials: MC
authors.lastname: Pessolani
mesh_terms: D018829:Adhesins, Bacterial / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D003599:Cytoskeleton / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology* / Q000648:ultrastructure; D054884:Host-Pathogen Interactions; D006801:Humans; D007918:Leprosy / Q000382:microbiology / Q000473:pathology; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D009166:Mycobacterium leprae / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D010587:Phagocytosis; D020543:Proteome / Q000032:analysis; D011650:Pulmonary Alveoli / Q000382:microbiology / Q000473:pathology; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D020543:Proteome; D011994:Recombinant Proteins