Novel vaginal microflora colonization model providing new insight into microbicide mechanism of action.
Novel vaginal microflora colonization model providing new insight into microbicide mechanism of action.
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新型的阴道菌群定殖模型为杀生作用机理提供了新的见解。
作者：
Fichorova RN;Yamamoto HS;Delaney ML;Onderdonk AB;Doncel GF
包括硫酸纤维素（CS）在内的几种广谱杀微生物剂已经通过了常规的临床前和I期临床安全性评价，但在II/III期试验中未能保护妇女免受HIV-1感染。目前的临床前算法在解决微生物群调节的阴道粘膜屏障的复杂性方面存在缺陷，这引起了人们的担忧。我们应用了一种新的微生物群定殖模型来评估CS和羟乙基纤维素（HEC），这是一种“通用安慰剂”在杀微生物剂试验。宫颈阴道上皮培养物用代表用作益生菌的常见乳杆菌属物种（嗜酸乳杆菌和乳杆菌）的正常阴道微生物区系分离物定殖。卷曲菌（Prevotella bivia）和阴道奇异菌（Atopobium vaginae），在细菌性阴道病（BV）的紊乱的微生物区系中最普遍。在基线时，所有菌株均保持恒定的上皮相关CFU，而不诱导细胞毒性和细胞凋亡。CS选择性减少上皮相关CFU和（在较小程度上）嗜酸性CFU，最显著影响L。卷曲的CS在无菌上皮培养物中仅诱导微小变化，在微生物群定殖的上皮中诱导先天免疫介质（RANTES、白细胞介素-8 [IL-8]和分泌性白细胞蛋白酶抑制剂[SLPI]）的表达，最显著地增强细菌引起BV的作用。在不存在CS的情况下，除嗜酸乳杆菌外的所有细菌菌株均激活NF-κB，尽管仅存在BV致病细菌时IL-8和RANTES水平升高。CS在所有条件下（包括嗜酸乳杆菌定植）均以剂量依赖性方式增强NF-κB活化。港灯仍然没有反应。这些结果为CS临床失败的可能机制提供了见解。细菌定植的宫颈阴道模型揭示了女性生殖道中微生物-上皮-药物相互作用和先天免疫的独特方面，应该成为抗HIV杀微生物剂和其他阴道制剂临床前安全性评价的一个组成部分。本报告提供的实验证据支持的概念，阴道微生物菌群调节上皮先天免疫的物种和菌株特异性的方式，局部应用杀微生物剂可能会改变细菌和上皮成分的这种稳态相互作用。我们的数据还强调了在评估阴道粘膜健康和免疫力时，区分生物医学干预对上皮相关与传统促炎细菌生长的影响的重要性。
Several broad-spectrum microbicides, including cellulose sulfate (CS), have passed conventional preclinical and phase I clinical safety evaluation and yet have failed to protect women from acquiring HIV-1 in phase II/III trials. Concerns have been raised that current preclinical algorithms are deficient in addressing the complexity of the microflora-regulated vaginal mucosal barrier. We applied a novel microflora-colonized model to evaluate CS and hydroxyethylcellulose (HEC), which is used as a “universal placebo” in microbicide trials. Cervicovaginal epithelial cultures were colonized with normal vaginal microflora isolates representing common Lactobacillus species used as probiotics (L. acidophilus and L. crispatus) or Prevotella bivia and Atopobium vaginae, most prevalent in the disturbed microflora of bacterial vaginosis (BV). At baseline, all strains maintained constant epithelium-associated CFUs without inducing cytotoxicity and apoptosis. CS selectively reduced epithelium-associated CFUs and (to a lesser extent) planktonic CFUs, most significantly affecting L. crispatus. Inducing only minor changes in sterile epithelial cultures, CS induced expression of innate immunity mediators (RANTES, interleukin-8 [IL-8], and secretory leukocyte protease inhibitor [SLPI]) in microflora-colonized epithelia, most significantly potentiating effects of bacteria causing BV. In the absence of CS, all bacterial strains except L. acidophilus activated NF-κB, although IL-8 and RANTES levels were increased by the presence of BV-causing bacteria only. CS enhanced NF-κB activation in a dose-dependent manner under all conditions, including L. acidophilus colonization. HEC remained inert. These results offer insights into possible mechanisms of CS clinical failure. The bacterially colonized cervicovaginal model reveals unique aspects of microflora-epithelium-drug interactions and innate immunity in the female genital tract and should become an integral part of preclinical safety evaluation of anti-HIV microbicides and other vaginal formulations. This report provides experimental evidence supporting the concept that the vaginal microflora regulates the epithelial innate immunity in a species- and strain-specific manner and that topically applied microbicides may alter both the bacterial and epithelial components of this homeostatic interaction. Our data also highlight the importance of differentiating the effects of biomedical interventions on epithelium-associated versus conventional planktonic bacterial growth when assessing vaginal mucosal health and immunity.