BACKGROUND: The transmission of Mycobacterium leprae, the causative pathogen of leprosy, has been postulated to occur mainly through upper respiratory route rather than skin-to-skin contact via minor injuries. The M. leprae genome contains mce1A gene, which encodes a putative mammalian cell entry protein. However, to date, there have been no functional analyses of the M. leprae mce1A gene product. OBJECTIVE: The aim of this study was to elucidate a possible relationship between this transmission mechanism and the mce1A gene product. METHODS: We analyzed the cell uptake activity in vitro of polystyrene latex beads coated with a purified recombinant (r-) protein expressed by a 849-bp locus within the mce1A gene. RESULTS: The r-protein promoted uptake of the beads into human nasal epithelial cells derived from nasal polyps, human bronchial epithelial cell line, normal human dermal fibroblasts, normal human microvascular endothelial cells and normal human keratinocytes cultured at 0.01 mM extracellular calcium concentration [Ca]; no uptake occurred with keratinocytes cultured at 1.2mM [Ca]. CONCLUSION: These results suggest that the mce1A gene product can mediate M. leprae entry into respiratory epithelial cells as their natural target cells, which may be the main mode of transmission. Endothelial cells, on the other hand, may serve as the reservoir of the bacilli for long-term infection. The M. leprae Mce1A protein has potential important implications for mode of transmission and pathogenesis of leprosy.
BACKGROUND: The transmission of Mycobacterium leprae, the causative pathogen of leprosy, has been postulated to occur mainly through upper respiratory route rather than skin-to-skin contact via minor injuries. The M. leprae genome contains mce1A gene, which encodes a putative mammalian cell entry protein. However, to date, there have been no functional analyses of the M. leprae mce1A gene product. OBJECTIVE: The aim of this study was to elucidate a possible relationship between this transmission mechanism and the mce1A gene product. METHODS: We analyzed the cell uptake activity in vitro of polystyrene latex beads coated with a purified recombinant (r-) protein expressed by a 849-bp locus within the mce1A gene. RESULTS: The r-protein promoted uptake of the beads into human nasal epithelial cells derived from nasal polyps, human bronchial epithelial cell line, normal human dermal fibroblasts, normal human microvascular endothelial cells and normal human keratinocytes cultured at 0.01 mM extracellular calcium concentration [Ca]; no uptake occurred with keratinocytes cultured at 1.2mM [Ca]. CONCLUSION: These results suggest that the mce1A gene product can mediate M. leprae entry into respiratory epithelial cells as their natural target cells, which may be the main mode of transmission. Endothelial cells, on the other hand, may serve as the reservoir of the bacilli for long-term infection. The M. leprae Mce1A protein has potential important implications for mode of transmission and pathogenesis of leprosy.
Authors: Filipe Rocha Lima; Fred Bernardes Filho; Vanderson Mayron Granemann Antunes; Jaci Maria Santana; Regina Coeli Palma de Almeida; Diana Mota Toro; Vinicius Fozatti Bragagnollo; Gabriel Martins da Costa Manso; Natália Aparecida de Paula; Eliracema Silva Alves; Lee W Riley; Sérgio Arruda; Marco Andrey Cipriani Frade Journal: Front Med (Lausanne) Date: 2022-06-09
Authors: Carlos A M Silva; Lia Danelishvili; Michael McNamara; Márcia Berredo-Pinho; Robert Bildfell; Franck Biet; Luciana S Rodrigues; Albanita V Oliveira; Luiz E Bermudez; Maria C V Pessolani Journal: Infect Immun Date: 2013-05-13 Impact factor: 3.441
Authors: Anna L Cogen; Stephen L Walker; Chrissy H Roberts; Deanna A Hagge; Kapil D Neupane; Saraswoti Khadge; Diana N J Lockwood Journal: PLoS Negl Trop Dis Date: 2012-11-01
Authors: Rahul Sharma; Ramanuj Lahiri; David M Scollard; Maria Pena; Diana L Williams; Linda B Adams; John Figarola; Richard W Truman Journal: Dis Model Mech Date: 2012-12-05 Impact factor: 5.758
Authors: Filipe R Lima; Iukary Takenami; Maurílio Al Cavalcanti; Lee W Riley; Sérgio Arruda Journal: Mem Inst Oswaldo Cruz Date: 2017-12 Impact factor: 2.743
Authors: Roberta Olmo Pinheiro; Veronica Schmitz; Bruno Jorge de Andrade Silva; André Alves Dias; Beatriz Junqueira de Souza; Mayara Garcia de Mattos Barbosa; Danuza de Almeida Esquenazi; Maria Cristina Vidal Pessolani; Euzenir Nunes Sarno Journal: Front Immunol Date: 2018-03-28 Impact factor: 7.561