title: Recombinant Staphylococcal Enterotoxin Type A Stimulate Antitumoral Cytokines.
abstract: About 20 different types of staphylococcal enterotoxins are produced by Staphylococcus aureus, in which type A is more common in food poisoning syndrome. Also staphylococcal enterotoxin A superantigen is a potent inducer of cytotoxic T lymphocyte activity and cytokine production and could stimulate T cells containing T-cell receptor beta chain domains when binding to major histocompatibility complex class II molecules. Hence, it is an important reagent in cancer immunotherapy.
  
  
  
  For the construction of pET-21a/ entA cassette, the staphylococcal enterotoxin type A gene was isolated from S aureus strain HN2, cloned into pET-21a, and introduced into Escherichia coli strain BL-21(DE3). Consequently, Western blot analysis showed pET-21a/ entA cassette expression inserted entA gene successfully. It is the first prompt using a pET-21a as a cloning vector for entA gene and expression of construct in BL-21(DE3). In addition, this study examined the ability of standard staphylococcal enterotoxin A and cloned staphylococcal enterotoxin A to activate T cells in vitro. Lymphocyte cells derived from lymph node BALB/c mice were exposed to standard staphylococcal enterotoxin A and cloned staphylococcal enterotoxin (1.10, 102,103, and 104 ng/µL) in order to evaluate the magnitude of proliferation, activation, and apoptosis of lymphocyte cells based on MTT and apoptosis assays, respectively.
  
  
  
  Our investigation showed that the function of cloned staphylococcal enterotoxin A was same as standard staphylococcal enterotoxin A, and the optimal concentration for the activation of lymphocyte cells and induction of apoptosis was 100 ng/µL and 1000 ng/µL ( P < .05), respectively. Quantification of cytokines clearly showed that lymphocyte cells exposed to standard staphylococcal enterotoxin A and cloned staphylococcal enterotoxin A significantly secreted higher interferon γ and tumor necrosis factor α compared to control.
  
  
  
  According to our results, the biological activity of standard staphylococcal enterotoxin A and cloned staphylococcal enterotoxin A is identical; therefore, these procedures may be approved as an efficient method to express and purify this protein in a large scale.
authors.affiliation: 1 Applied Microbiology, Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Agheli
authors.affiliation: 1 Applied Microbiology, Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Bijan
authors.initials: B
authors.lastname: Emkanian
authors.affiliation: 1 Applied Microbiology, Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Raheleh
authors.initials: R
authors.lastname: Halabian
authors.affiliation: 1 Applied Microbiology, Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Jalil
authors.initials: J
authors.lastname: Fallah Mehrabadi
authors.affiliation: 1 Applied Microbiology, Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas Ali
authors.initials: AA
authors.lastname: Imani Fooladi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation; D003001:Cloning, Molecular; D016207:Cytokines / Q000097:blood / Q000378:metabolism*; D004768:Enterotoxins / Q000235:genetics / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression; D007371:Interferon-gamma / Q000097:blood / Q000378:metabolism; D015847:Interleukin-4 / Q000097:blood / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000494:pharmacology*
chemical_list: D016207:Cytokines; D004768:Enterotoxins; D011994:Recombinant Proteins; D015847:Interleukin-4; C026066:enterotoxin A, Staphylococcal; D007371:Interferon-gamma
keywords: SEA; Staphylococcus aureus; bioactivity; cloning; expression