Aggregation of hapten-bearing liposomes mediated by specific antibodies.
Aggregation of hapten-bearing liposomes mediated by specific antibodies.
复制标题
由特异性抗体介导的带有半抗原的脂质体的聚集。
DOI：
10.1016/s0006-3495(93)81453-x
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发表时间：
1993
影响因子：
3.4
通讯作者：
Owicki,JC
中科院分区：
文献类型：
--
作者：
Lee,KD;Kantor,AB;Nir,S;Owicki,JC
我们研究了模型系统中配体-受体结合介导的特定膜-膜相互作用，该模型系统由 (a) FG3P 组成，荧光素半抗原通过肽基间隔物连接到磷脂上，如前所述（Petrossian, A., A.B. Kantor, and J.C. Owicki. 1985. J. Lipid Res. 26:767–773）， (b) 抗荧光素单克隆抗体 (MAb)，和 (c) 掺入 FG3P 的磷脂囊泡（脂质体）。通过差速离心研究了四种单克隆抗体对带有半抗原的脂质体的聚集。 MAb 诱导囊泡聚集的能力差异很大，并且与亲和力成反比。通过比浊法和冷冻断裂电子显微镜对在整个聚集过程中冷冻的样品进行了更详细的研究，其中一种单克隆抗体的聚集。使用双丙烷喷射装置实现快速冷冻。聚集体形态和聚集体尺寸分布的时间演化是通过立体校正的二维裂缝视图获得的。通过根据具有两个参数（抗体介导的囊泡聚集和解聚的速率常数）的质量作用模型考虑动态聚集来模拟聚集动力学。两个速率常数均比非聚集条件下抗体与溶液中或囊泡上的半抗原的相应相互作用的速率常数低几个数量级。
We studied specific membrane-membrane interactions mediated by ligand-receptor binding in a model system, which consisted of (a) FG3P, the fluorescein hapten attached to a phospholipid by a peptidyl spacer as described previously (Petrossian, A., A.B. Kantor, and J.C. Owicki. 1985. J. Lipid Res. 26:767–773), (b) antifluorescein monoclonal antibodies (MAbs), and (c) phospholipid vesicles (liposomes) into which the FG3P was incorporated. The aggregation of the hapten-bearing liposomes by four MAbs was studied by differential centrifugation. The ability of the MAbs to induce vesicle aggregation varied considerably and correlated inversely with affinity. Aggregation by one of the MAbs was studied in more detail by turbidimetry and freeze-fracture electron microscopy of samples frozen throughout the course of the aggregation. Rapid freezing was achieved with a double propane-jet apparatus. The aggregate morphologies and the time evolution of the aggregate size distribution were obtained from the two-dimensional fracture views with a stereological correction. The aggregation kinetics were simulated by considering dynamical aggregation according to a mass-action model with two parameters, the rate constants for antibody-mediated vesicle aggregation and disaggregation. Both rate constants were orders of magnitude lower than the rate constants for the corresponding interactions of antibodies with haptens either in solution or on vesicles under nonaggregating conditions.