Oku Teruaki, Soma Hikari, Kurisaka Chisato, Tsuji Tsutomu
Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences , Tokyo, Japan .
Monoclon Antib Immunodiagn Immunother. 2018 Nov;37(5):212-217. doi: 10.1089/mab.2018.0016.
Staphylococcus aureus secretes a family of exoproteins structurally homologous to bacterial superantigens, such as toxic shock syndrome toxin-1 (TSST-1), and those exoproteins are thus called staphylococcal superantigen-like proteins (SSLs). Recent studies have revealed that SSLs play roles in evasion of the host defense by disturbing host immune responses. We previously reported that staphylococcal superantigen-like protein 5 (SSL5; a member of the SSL family) inhibited matrix metalloproteinase-9 (MMP-9), which is crucial for leukocyte recruitment to sites of infection. In this study, we established a mouse hybridoma clone (30G5C) producing a monoclonal antibody specific for SSL5. In immunoblotting analysis using recombinant His-tagged SSL1 to SSL14 (His-SSLs), the antibody was found to specifically recognize SSL5 without crossreactivity with other His-SSLs. The antibody bound to the C-terminal region of SSL5 (β-grasp domain), but did not interfere with the binding of SSL5 to MMP-9, suggesting that this antibody is useful for identification of SSL5-producing S. aureus and screening for inhibitors of the SSL5/MMP-9 complex formation.
金黄色葡萄球菌分泌一类与细菌超抗原结构同源的外蛋白，如中毒性休克综合征毒素-1（TSST-1），因此这些外蛋白被称为葡萄球菌超抗原样蛋白（SSLs）。最近的研究表明，SSLs通过干扰宿主免疫反应在逃避宿主防御中发挥作用。我们之前报道过，葡萄球菌超抗原样蛋白5（SSL5；SSL家族成员之一）可抑制基质金属蛋白酶-9（MMP-9），而MMP-9对白细胞募集到感染部位至关重要。在本研究中，我们建立了一个产生针对SSL5的单克隆抗体的小鼠杂交瘤克隆（30G5C）。在使用重组His标签的SSL1至SSL14（His-SSLs）进行的免疫印迹分析中，发现该抗体能特异性识别SSL5，而不与其他His-SSLs发生交叉反应。该抗体与SSL5的C末端区域（β-抓握结构域）结合，但不干扰SSL5与MMP-9的结合，这表明该抗体可用于鉴定产生SSL5的金黄色葡萄球菌以及筛选SSL5/MMP-9复合物形成的抑制剂。
