Effect of B-cell depletion on vaginal microbiota and mucosal immunity

项目概要 阴道微生物组在生殖健康结果中发挥着重要作用，影响女性的机会 妊娠着床、流产、低出生体重、早产和性传播疾病的发生 感染。虽然许多研究表明女性生殖道 (FGT) 微生物群的变化驱动 由于粘膜免疫环境的变化，很少有研究探索另一种可能性： 宿主粘膜免疫的变化决定了阴道微生物群落的组成。我们有 描述了接受利妥昔单抗（一种抗 CD20）治疗的女性出现的乳酸菌缺乏性炎症性阴道炎 导致全身 B 细胞耗竭的抗体。这一观察结果使我们推测 B 细胞和 阴道液抗体调节阴道微生物群的组成，控制 大肠杆菌和 B 族链球菌等病原体，并促进乳杆菌的优势。 尽管 B 细胞、抗体和微生物群之间的关联已在肠道中得到描述，但这是一个 女性生殖道中未探索的区域。我们提出的项目在探索 B 细胞的作用方面都很新颖 和抗体调节阴道微生物群，而且还使用临床利妥昔单抗治疗作为体内 实验模型。这项探索性资助有可能确定非常重要的生物学机制 FGT 微生物群和粘膜炎症的调节，两者都与不良生殖有关 健康结果。为了检验我们的假设，我们提出了一项观察性研究，比较接受治疗的女性 将利妥昔单抗用于健康对照，以确定 B 细胞在确定阴道微生物群组成中的作用。 在目标 1 中，我们将比较阴道微生物群、宫颈免疫细胞、阴道液免疫球蛋白和 40 名接受利妥昔单抗治疗的女性与 40 名健康对照者之间的可溶性炎症标志物。我们会 还比较了接受利妥昔单抗治疗的炎症性阴道炎女性和那些患有炎症性阴道炎的女性之间的这些标记物 没有。在目标 2 中，我们将通过比较我们的变化来评估与 B 细胞耗竭的因果关系。 在 1) 开始、2) 停止和 3) 利妥昔单抗治疗稳定的女性中随时间测量的分析物 （每组 n = 10）。我们对免疫细胞群和可溶性标记物的局部阴道测量将是 与 B 细胞数量和 IgG 水平的系统测量结果进行比较。使用利妥昔单抗治疗 体内实验模型将为研究系统免疫在调节中的作用提供新的机会 阴道微生物群和粘膜免疫反应，这将导致对阴道微生物群和粘膜免疫反应的更广泛了解 和全身粘膜免疫。

PROJECT SUMMARY The vaginal microbiome plays a significant role in reproductive health outcomes, influencing a woman’s chances of pregnancy implantation, miscarriage, low birth weight, preterm delivery, and acquisition of sexually transmitted infections. While many studies have shown that changes in the female genital tract (FGT) microbiota drive changes in the mucosal immune environment, there are few studies that have explored the alternate possibility: that changes in host mucosal immunity determine the composition of the vaginal microbial community. We have described a Lactobacillus-deficient, inflammatory vaginitis in women treated with rituximab, an anti-CD20 antibody which leads to systemic B-cell depletion. This observation led us to hypothesize that B-cells and vaginal fluid antibodies regulate the composition of the vaginal microbiota, controlling levels of pathobionts such as E. coli and Group B streptococcus and facilitating Lactobacillus dominance. Although associations between B-cells, antibodies and microbiota have been described in the gut, this is an unexplored area in the female genital tract. Our proposed project is novel in both exploring the role of B-cells and antibodies in regulation of vaginal microbiota, but also in using clinical rituximab treatment as an in vivo experimental model. This exploratory grant has potential to identify highly significant biologic mechanisms for regulation of FGT microbiota and mucosal inflammation, both of which are associated with adverse reproductive health outcomes. To test our hypothesis, we propose an observational study comparing women treated with rituximab to healthy controls to identify the role of B-cells in determining the composition of the vaginal microbiota. In Aim 1 we will compare the vaginal microbiota, cervical immune cells, vaginal fluid immunoglobulins and soluble markers of inflammation between 40 women being treated with rituximab to 40 healthy controls. We will also compare these markers between women being treated with rituximab with inflammatory vaginitis and those without. In Aim 2, we will assess the causal relationship with B-cell depletion by comparing changes in our measured analytes over time in women who are 1) starting, 2) stopping and 3) stable on treatment with rituximab (n = 10 in each group). Our local vaginal measurements of immune cell populations and soluble markers will be compared with systemic measurements of B-cell numbers and IgG levels. Using rituximab treatment as an in vivo experimental model will provide a novel opportunity to examine the role of systemic immunity in regulating the vaginal microbiota and mucosal immune responses, which will lead to broader understanding of both vaginal and systemic mucosal immunity.