Mina Hemmati1, Atefeh Seghatoleslam2, Mozhgan Rasti3, Saeedeh Ebadat3, Fakhraddin Naghibalhossaini3, Zohreh Mostafavi-Pour4. 1. Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran; Department of Biochemistry, School of Medicine, Birjand University of Medical Sciences, Birjand, Islamic Republic of Iran. 2. Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran; Histomorphometry and Steriology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran. 3. Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran. 4. Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran; Maternal-Fetal Medicine Research Center, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran. Electronic address: zmostavaripour88@yahoo.co.uk.
Abstract
BACKGROUND/ PURPOSE: Tuberculous granulomas are the sites of interaction between the T cells, macrophages, and extracellular matrix (ECM) to control the infection caused by Mycobacterium tuberculosis (M. tuberculosis). A predominant role of RD-1-encoded secretory proteins, early secreted antigenic target-6 (ESAT-6), and culture filtrate protein-10 (CFP-10) in the formation of granulomas has recently been emphasized. However, the precise molecular events that induce the formation of these granulomatous structures are yet to be elucidated. Macrophages use integrins to adhere to fibronectin (FN) as a major component of the ECM. The major goal of this study was to investigate whether recombinant M. tuberculosis antigens can modulate integrin-mediated macrophage adhesion. METHODS: Differentiated THP-1 cell line was stimulated with recombinant ESAT-6, CFP-10, and ESAT-6/CFP-10 proteins and evaluated for alterations in the expression levels of α5β1 and α4β1 by semiquantitative real-time polymerase chain reaction. The role of these recombinant antigens in the cytoskeleton rearrangement was determined by adhesion assay and immunofluorescent microscopy. RESULTS: Our data showed that ESAT-6 and ESAT-6/CFP-10 fusion proteins could induce adhesion of macrophages to FN through α4β1 integrin. An increased expression level of α4β1 integrin in comparison with α5β1 integrin in differentiated THP-1 cells was also observed. Results of immunofluorescence studies showed that recombinant proteins-treated THP-1 cells form well-organized stress fibers and focal contacts containing vinculin compared with untreated THP-1 cells. CONCLUSION: Increased expression level of α4β1 in differentiated THP-1 cells could suggest the important role of α4β1 integrin in adhesion and focal contact formation of macrophages exposed to M. tuberculosis antigens.
BACKGROUND/ PURPOSE:Tuberculous granulomas are the sites of interaction between the T cells, macrophages, and extracellular matrix (ECM) to control the infection caused by Mycobacterium tuberculosis (M. tuberculosis). A predominant role of RD-1-encoded secretory proteins, early secreted antigenic target-6 (ESAT-6), and culture filtrate protein-10 (CFP-10) in the formation of granulomas has recently been emphasized. However, the precise molecular events that induce the formation of these granulomatous structures are yet to be elucidated. Macrophages use integrins to adhere to fibronectin (FN) as a major component of the ECM. The major goal of this study was to investigate whether recombinant M. tuberculosis antigens can modulate integrin-mediated macrophage adhesion. METHODS: Differentiated THP-1 cell line was stimulated with recombinant ESAT-6, CFP-10, and ESAT-6/CFP-10 proteins and evaluated for alterations in the expression levels of α5β1 and α4β1 by semiquantitative real-time polymerase chain reaction. The role of these recombinant antigens in the cytoskeleton rearrangement was determined by adhesion assay and immunofluorescent microscopy. RESULTS: Our data showed that ESAT-6 and ESAT-6/CFP-10 fusion proteins could induce adhesion of macrophages to FN through α4β1 integrin. An increased expression level of α4β1 integrin in comparison with α5β1 integrin in differentiated THP-1 cells was also observed. Results of immunofluorescence studies showed that recombinant proteins-treated THP-1 cells form well-organized stress fibers and focal contacts containing vinculin compared with untreated THP-1 cells. CONCLUSION: Increased expression level of α4β1 in differentiated THP-1 cells could suggest the important role of α4β1 integrin in adhesion and focal contact formation of macrophages exposed to M. tuberculosis antigens.
Authors: William H Conrad; Morwan M Osman; Jonathan K Shanahan; Frances Chu; Kevin K Takaki; James Cameron; Digby Hopkinson-Woolley; Roland Brosch; Lalita Ramakrishnan Journal: Proc Natl Acad Sci U S A Date: 2017-01-24 Impact factor: 11.205
Authors: Fantahun Biadglegne; Johannes R Schmidt; Kathrin M Engel; Jörg Lehmann; Robert T Lehmann; Anja Reinert; Brigitte König; Jürgen Schiller; Stefan Kalkhof; Ulrich Sack Journal: Biomedicines Date: 2022-03-27