title: PE_PGRS33 Contributes to Mycobacterium tuberculosis Entry in Macrophages through Interaction with TLR2.
abstract: PE_PGRS represent a large family of proteins typical of pathogenic mycobacteria whose members are characterized by an N-terminal PE domain followed by a large Gly-Ala repeat-rich C-terminal domain. Despite the abundance of PE_PGRS-coding genes in the Mycobacterium tuberculosis (Mtb) genome their role and function in the biology and pathogenesis still remains elusive. In this study, we generated and characterized an Mtb H37Rv mutant (MtbΔ33) in which the structural gene of PE_PGRS33, a prototypical member of the protein family, was inactivated. We showed that this mutant entered macrophages with an efficiency up to ten times lower than parental or complemented strains, while its efficiency in infecting pneumocytes remained unaffected. Interestingly, the lack of PE_PGRS33 did not affect the intracellular growth of this mutant in macrophages. Using a series of functional deletion mutants of the PE_PGRS33 gene to complement the MtbΔ33 strain, we demonstrated that the PGRS domain is required to mediate cell entry into macrophages, with the key domain encompassing position 140-260 amino acids of PE_PGRS33. PE_PGRS33-mediated entry into macrophages was abolished in TLR2-deficient mice, as well as following treatment with wortmannin or an antibody against the complement receptor 3 (CR3), indicating that PE_PGRS33-mediated entry of Mtb in macrophages occurs through interaction with TLR2.
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Palucci
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Camassa
authors.affiliation: Department of Molecular Medicine, University of Padua, Via A. Gabelli, 63-35121, Padua, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cascioferro
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Sali
authors.affiliation: Department of Molecular Medicine, University of Padua, Via A. Gabelli, 63-35121, Padua, Italy.
authors.forename: Saber
authors.initials: S
authors.lastname: Anoosheh
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Zumbo
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Mariachiara
authors.initials: M
authors.lastname: Minerva
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Iantomasi
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: De Maio
authors.affiliation: Institute of General Pathology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Di Sante
authors.affiliation: Institute of General Pathology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ria
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Sanguinetti
authors.affiliation: Department of Molecular Medicine, University of Padua, Via A. Gabelli, 63-35121, Padua, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Palù
authors.affiliation: Aeras, Rockville (MD), United States of America.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Brennan
authors.affiliation: Department of Molecular Medicine, University of Padua, Via A. Gabelli, 63-35121, Padua, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Manganelli
authors.affiliation: Institute of Microbiology, Università Cattolica del Sacro Cuore, L.go A. Gemelli, 8-00168, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Delogu
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D008264:Macrophages / Q000382:microbiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D051195:Toll-Like Receptor 2 / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D051195:Toll-Like Receptor 2