title: Additive effect of recombinant Mycobacterium tuberculosis ESAT-6 protein and ESAT-6/CFP-10 fusion protein in adhesion of macrophages through fibronectin receptors.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  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.affiliation: 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.
authors.forename: Mina
authors.initials: M
authors.lastname: Hemmati
authors.affiliation: 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.
authors.forename: Atefeh
authors.initials: A
authors.lastname: Seghatoleslam
authors.affiliation: Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran.
authors.forename: Mozhgan
authors.initials: M
authors.lastname: Rasti
authors.affiliation: Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran.
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Ebadat
authors.affiliation: Recombinant Protein Laboratory, School of Advanced Medical Sciences and Technologies, Department of Biochemistry, Shiraz University of Medical Sciences, Shiraz, Islamic Republic of Iran.
authors.forename: Fakhraddin
authors.initials: F
authors.lastname: Naghibalhossaini
authors.affiliation: 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.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Mostafavi-Pour
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D005353:Fibronectins / Q000378:metabolism*; D020869:Gene Expression Profiling; D054884:Host-Pathogen Interactions; D006801:Humans; D039041:Integrin alpha4beta1 / Q000032:analysis / Q000235:genetics; D039081:Integrin alpha5beta1 / Q000032:analysis / Q000235:genetics; D008264:Macrophages / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000502:physiology*; D011485:Protein Binding; D017469:Receptors, Fibronectin / Q000032:analysis* / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D005353:Fibronectins; D039041:Integrin alpha4beta1; D039081:Integrin alpha5beta1; D017469:Receptors, Fibronectin; D011994:Recombinant Proteins
keywords: Mycobacterium tuberculosis; early secreted antigenic target-6/culture filtrate protein-10 fusion protein; integrin