Differential neutralizing activities of a single domain camelid antibody (VHH) specific for ricin toxin's binding subunit (RTB).
Differential neutralizing activities of a single domain camelid antibody (VHH) specific for ricin toxin's binding subunit (RTB).
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ricin毒素的结合亚基（RTB）的单个结构域Camelid抗体（VHH）的差异中和活性。
DOI：
10.1371/journal.pone.0099788
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Mantis NJ
中科院分区：
文献类型：
--
作者：
Herrera C;Vance DJ;Eisele LE;Shoemaker CB;Mantis NJ
蓖麻毒素是核糖体失活蛋白A-B家族的成员，由于其潜在的生物威胁剂的用途，被疾病控制和预防中心归类为选择毒素。为了设计蓖麻毒素的治疗方法，我们最近生产了一系列羊驼衍生的、仅重链的抗体VH结构域（VHH或“纳米抗体”），其对蓖麻毒素的酶（RTA）和结合（RTB）亚基具有特异性。我们报道了一种特定的RTB特异性VHH，RTB-B7，当通过肽间隔物共价连接到不同的RTA特异性VHH时，产生异二聚体，如VHH D10/B7，其能够被动保护小鼠免受蓖麻毒素的致死剂量攻击。然而，RTB-B7本身，当与蓖麻毒素以1∶10的毒素：抗体比例混合时，在体内没有提供任何保护，即使它在体外具有明显的毒素中和活性。为了更好地定义与蓖麻毒素中和相关的抗体在体外和体内的具体属性，我们进行了更彻底的RTB-B7的表征。我们报告说，RTB-B7，即使在100倍摩尔过量（毒素：抗体）是无法改变蓖麻毒素在小鼠模型中的毒性。另一方面，在两个完善的细胞毒性试验中，RTB-B7中和蓖麻毒素的50%抑制浓度（IC 50）相当于24 B11，一种充分表征和有效的RTB特异性鼠单克隆抗体。事实上，RTB-B7和24 B11在一系列体外试验中进行比较时几乎是相同的，包括毒素与细胞表面受体预结合后对蓖麻毒素的粘附和中和。RTB-B7与24 B11和VHH D10/B7的不同之处在于，它在阻断蓖麻毒素与宿主细胞上的受体的附着方面相对不太有效，并且不能在溶液中形成高分子量毒素：抗体复合物。这些活动是否是重要的蓖麻毒素中和活性在体内仍有待确定。
Ricin, a member of the A-B family of ribosome-inactivating proteins, is classified as a Select Toxin by the Centers for Disease Control and Prevention because of its potential use as a biothreat agent. In an effort to engineer therapeutics for ricin, we recently produced a collection of alpaca-derived, heavy-chain only antibody VH domains (VHH or “nanobody”) specific for ricin’s enzymatic (RTA) and binding (RTB) subunits. We reported that one particular RTB-specific VHH, RTB-B7, when covalently linked via a peptide spacer to different RTA-specific VHHs, resulted in heterodimers like VHH D10/B7 that were capable of passively protecting mice against a lethal dose challenge with ricin. However, RTB-B7 itself, when mixed with ricin at a 1∶10 toxin:antibody ratio did not afford any protection in vivo, even though it had demonstrable toxin-neutralizing activity in vitro. To better define the specific attributes of antibodies associated with ricin neutralization in vitro and in vivo, we undertook a more thorough characterization of RTB-B7. We report that RTB-B7, even at 100-fold molar excess (toxin:antibody) was unable to alter the toxicity of ricin in a mouse model. On the other hand, in two well-established cytotoxicity assays, RTB-B7 neutralized ricin with a 50% inhibitory concentration (IC50) that was equivalent to that of 24B11, a well-characterized and potent RTB-specific murine monoclonal antibody. In fact, RTB-B7 and 24B11 were virtually identical when compared across a series of in vitro assays, including adherence to and neutralization of ricin after the toxin was pre-bound to cell surface receptors. RTB-B7 differed from both 24B11 and VHH D10/B7 in that it was relatively less effective at blocking ricin attachment to receptors on host cells and was not able to form high molecular weight toxin:antibody complexes in solution. Whether either of these activities is important in ricin toxin neutralizing activity in vivo remains to be determined.
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影响因子：
6.2
作者：
Anderson, George P.;Glaven, Richard H.;Goldman, Ellen R.
通讯作者：
Goldman, Ellen R.
影响因子：
11.8
作者：
Plotkin, Stanley A.
通讯作者：
Plotkin, Stanley A.
影响因子：
3.7
作者：
Greene, Christopher J.;Chadwick, Chrystal M.;Connell, Terry D.
通讯作者：
Connell, Terry D.
DOI：
10.3390/s90100542
发表时间：
2009
期刊：
Sensors (Basel, Switzerland)
影响因子：
--
作者：
Goldman ER;Liu JL;Bernstein RD;Swain MD;Mitchell SQ;Anderson GP
通讯作者：
Anderson GP
影响因子：
2.7
作者：
Anderson, George P.;Matney, Russell;Goldman, Ellen R.
通讯作者：
Goldman, Ellen R.