title: New Recombinant Mycobacterium bovis BCG Expression Vectors: Improving Genetic Control over Mycobacterial Promoters.
abstract: The expression of many antigens, stimulatory molecules, or even metabolic pathways in mycobacteria such as Mycobacterium bovis BCG or M. smegmatis was made possible through the development of shuttle vectors, and several recombinant vaccines have been constructed. However, gene expression in any of these systems relied mostly on the selection of natural promoters expected to provide the required level of expression by trial and error. To establish a systematic selection of promoters with a range of strengths, we generated a library of mutagenized promoters through error-prone PCR of the strong PL5 promoter, originally from mycobacteriophage L5. These promoters were cloned upstream of the enhanced green fluorescent protein reporter gene, and recombinant M. smegmatis bacteria exhibiting a wide range of fluorescence levels were identified. A set of promoters was selected and identified as having high (pJK-F8), intermediate (pJK-B7, pJK-E6, pJK-D6), or low (pJK-C1) promoter strengths in both M. smegmatis and M. bovisBCG. The sequencing of the promoter region demonstrated that it was extensively modified (6 to 11%) in all of the plasmids selected. To test the functionality of the system, two different expression vectors were demonstrated to allow corresponding expression levels of the Schistosoma mansoni antigen Sm29 in BCG. The approach used here can be used to adjust expression levels for synthetic and/or systems biology studies or for vaccine development to maximize the immune response.
authors: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil.|Programa de Pós Graduação Interunidades em Biotecnologia USP-IPT-IB, São Paulo, Brazil.
authors: Alex I
authors: AI
authors: Kanno
authors: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil.|Programa de Pós Graduação Interunidades em Biotecnologia USP-IPT-IB, São Paulo, Brazil.
authors: Cibelly
authors: C
authors: Goulart
authors: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil.|Programa de Pós Graduação Interunidades em Biotecnologia USP-IPT-IB, São Paulo, Brazil.
authors: Henrique K
authors: HK
authors: Rofatto
authors: Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
authors: Sergio C
authors: SC
authors: Oliveira
authors: Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil.
authors: Luciana C C
authors: LCC
authors: Leite
authors: Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, United Kingdom j.mcfadden@surrey.ac.uk.
authors: Johnjoe
authors: J
authors: McFadden
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000096:biosynthesis / Q000235:genetics; D019677:Artificial Gene Fusion; D003001:Cloning, Molecular; D015870:Gene Expression; D017930:Genes, Reporter; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D015801:Helminth Proteins / Q000096:biosynthesis / Q000235:genetics; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics; D016296:Mutagenesis; D009160:Mycobacteriophages / Q000235:genetics; D009163:Mycobacterium bovis / Q000235:genetics*; D020102:Mycobacterium smegmatis / Q000235:genetics; D010957:Plasmids; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012550:Schistosoma mansoni / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D000947:Antigens, Helminth; D015801:Helminth Proteins; D008562:Membrane Glycoproteins; C000589456:Sm29 protein, Schistosoma mansoni; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins