en ایمنی شناسی Immunology مقاله پژوهشی Original Research Article <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt">Introduction: Infectious diseases are one of the main causes of death worldwide. This has driven scientists to invest in extraction and identification of antimicrobial agents from natural toxins and presentation of novel antibiotics and vaccines. The aim of the current study is to investigate the antibacterial and cytotoxicity effects of the protective antigen domain 4 (PAD4) from Bacillus anthracis as a strong immunogen and vaccine candidate for B. anthracis.</span></span></span><br> <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt">Matherial and Methods: In this study, the antibacterial effect of the antigen was evaluated in concentrations of 0.28-4.5&mu;g/ml using MTT reduction and MIC assays and the anticancer effect of the recombinant PAD4 on MCF-7 cell line was examined in concentrations of 0.5-2&mu;g/ml via MTT, neutral red uptake, and comet assays. NO, GSH and catalase determination assays following the treatment with PAD4 was also evaluated. </span></span></span><br> <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt">Results: According to the antibacterial results, PAD4 did not show any antibacterial effect against S. aureus, but very little inhibition on E. coli cells&#39; growth was recorded. The results of MTT and neutral red assays showed that this antigen has a significant inhibiting effect on cancer cell growth. Comet assay results showed that PAD4 can cause death of breast cancer cells by apoptosis induction. NO, GSH and catalase determination assays did not show any significant fluctuations following the treatment with PAD4.</span></span></span><br> <span style="font-size:11pt"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt">Conclusion: Our results showed that this antigen does not have any antibacterial effect but it can inhibit the proliferation of breast cancer cells, making PAD4 a candidate for producing antitumor drugs.</span></span></span> Bacillus anthracis, PAD4, Antibacterial, Cell toxicity, Anticancer 61 69 http://modernmedlab.com/browse.php?a_code=A-10-73-16&slc_lang=en&sid=1 Mohsen Parsa bardaskancity@yahoo.com 10031947532846002012 10031947532846002012 No The center of biological science and technology, Imam Hussein University, Tehran, Iran Jamil Zargan kpahaji@ihu.ac.ir 10031947532846002013 10031947532846002013 Yes The center of biological science and technology, Imam Hussein University, Tehran, Iran Hossein Honari honari.hosein@gmail.com 10031947532846002014 10031947532846002014 No The center of biological science and technology, Imam Hussein University, Tehran, Iran Ashkan Hajinourmohammadi ashkan.genetics@gmail.com 10031947532846002015 10031947532846002015 No The center of biological science and technology, Imam Hussein University, Tehran, Iran Seyyed Mohsen Mousavi smousavi@gmail.com 10031947532846002016 10031947532846002016 No The center of biological science and technology, Imam Hussein University, Tehran, Iran Hani Keshavarz Alikhani Hani.Keshavarz865@gmail.com 10031947532846002017 10031947532846002017 No Biology Department, Razi University, Kermanshah, Iran