MassBiologics of the University of Massachusetts Medical School, 460 Walk Hill St., Mattapan, MA 02126, USA.
Vaccine. 2020 Nov 3;38(47):7490-7497. doi: 10.1016/j.vaccine.2020.09.070. Epub 2020 Oct 8.
Mucosal surfaces of the gastrointestinal tract play an important role in immune homeostasis and defense and may be compromised by enteric disorders or infection. Therapeutic intervention using monoclonal antibody (mAb) offers the potential for treatment with minimal off-target effects as well as the possibility of limited systemic exposure when administered orally. Critically, to achieve efficacy at luminal surfaces, mAb must remain stable and functionally active in the gastrointestinal environment. To better understand the impact of isotype, class, and molecular structure on the intestinal stability of recombinant antibodies, we used an in vitro simulated intestinal fluid (SIF) assay to evaluate a panel of antibody candidates for enteric mAb-based therapeutics. Recombinant IgG1 was the least stable following SIF incubation, while the stability of IgA generally increased upon polymerization, with subtle differences between subclasses. Notably, patterns of variability within and between mAbs suggest that variable regions contribute to mAb stability and potentially mediate mAb susceptibility to proteases. Despite relatively rapid degradation in SIF, mAbs targeting Enterotoxigenic Escherichia coli (ETEC) displayed functional activity following SIF treatment, with SIgA1 showing improved function compared to SIgA2. The results of this study have implications for the design of enteric therapeutics and subsequent selection of lead candidates based upon in vitro intestinal stability assessments.
胃肠道的黏膜表面在免疫稳态和防御中起着重要作用，但可能会受到肠道疾病或感染的损害。使用单克隆抗体（mAb）进行治疗干预具有最小的脱靶效应的治疗潜力，并且当口服给药时，系统暴露的可能性有限。至关重要的是，为了在腔表面实现疗效，mAb 必须在胃肠道环境中保持稳定和功能活性。为了更好地了解同种型、类别和分子结构对重组抗体肠道稳定性的影响，我们使用体外模拟肠液（SIF）测定法来评估一系列候选抗体，以用于基于 mAb 的肠道治疗。SIF 孵育后，重组 IgG1 的稳定性最差，而 IgA 的稳定性通常在聚合后增加，亚类之间存在细微差异。值得注意的是，mAb 内和之间的可变性模式表明可变区有助于 mAb 的稳定性，并可能介导 mAb 对蛋白酶的敏感性。尽管在 SIF 中降解相对较快，但针对肠致病性大肠杆菌（ETEC）的 mAb 在 SIF 处理后仍显示出功能活性，与 SIgA2 相比，SIgA1 显示出改善的功能。这项研究的结果对肠道治疗药物的设计和随后基于体外肠道稳定性评估选择候选药物具有重要意义。
