Toward a more accurate quantitation of the activity of recombinant retroviruses: Alternatives to titer and multiplicity of infection
Toward a more accurate quantitation of the activity of recombinant retroviruses: Alternatives to titer and multiplicity of infection
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DOI：
10.1128/jvi.74.3.1258-1266.2000
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发表时间：
2000-02-01
影响因子：
5.4
通讯作者：
Morgan, JR
中科院分区：
文献类型：
--
作者：
Andreadis, S;Lavery, T;Morgan, JR
在本文中，我们提出了一个数学模型与实验支持的几个关键参数如何控制活性逆转录病毒颗粒吸附到粘附细胞表面上，这些参数，包括吸附时间，病毒体积，和靶细胞的数量，大小和类型，以及病毒的内在性质，扩散系数和半衰期（t（1/2）），已经被并入描述活性病毒颗粒吸附到细胞表面的速率的数学表达式中。从这个表达式中，我们得到了C-vo的估计。活性逆转录病毒颗粒的起始浓度。与滴度相反，C-vo不依赖于测定的特定条件。逆转录病毒颗粒的相对缓慢的扩散（D = 2 × 10（-8）cm（2）/s）和快速衰减（t（1/2）= 6至7 h）解释了为什么C-vo值显著高于滴度值。C-VO的值还表明，逆转录病毒原液中缺陷颗粒的数量远低于以前的想法，这尤其对逆转录病毒用于体内基因治疗具有意义。使用该表达式，我们还计算了AVC（活性病毒/细胞），即在给定吸附时间内每个细胞吸附的活性逆转录病毒颗粒的数量。与基于滴度的感染多重性相比，AVC基于转导测定的理化参数，因此是更可靠的替代方法。
In this paper, we present a mathematical model with experimental support of how several key parameters govern the adsorption of active retro-virus particles onto the surface of adherent cells, These parameters, including time of adsorption, volume of virus, and the number, size, and type of target cells, as well as the intrinsic properties of the virus, diffusion coefficient, and half-life (t(1/2)), have been incorporated into a mathematical expression that describes the rate at which active virus particles adsorb to the cell sm face. From this expression, we have obtained estimates of C-vo. the starting concentration of active retrovirus particles. In contrast to titer, C-vo is independent of the specific conditions of the assay. The relatively slow diffusion (D = 2 x 10(-8) cm(2)/s) and rapid decay (t(1/2) = 6 to 7 h) of retrovirus particles explain why C-vo values are significantly higher than titer values. Values of C-vo also indicate that the number of defective particles in a retrovirus stock is much lower than previously thought, which has implications especially for the use of retroviruses for in vivo gene therapy. With this expression, we have also computed AVC (active viruses/cell), the number of active retrovirus particles that would adsorb per cell during a gives adsorption time. In contrast to multiplicity of infection, which is based an titer and is subject to the same inaccuracies, AVC is based on the physicochemical parameters of the transduction assay and so is a more reliable alternative.