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

项目总结 阴道微生物群在生殖健康结果中发挥着重要作用，影响着女性的机会 妊娠植入、流产、低出生体重、早产和获得性传播疾病 感染。虽然许多研究表明，女性生殖道(FGT)微生物区系的变化 关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 描述了一种使用抗CD20的利妥昔单抗治疗的女性乳杆菌缺乏性炎症性阴道炎 导致全身B细胞耗尽的抗体。这一观察结果使我们假设B细胞和 阴道液抗体调节阴道微生物区系的组成，控制 致病菌，如大肠杆菌和B组链球菌，并促进乳杆菌优势。 尽管在肠道中已经描述了B细胞、抗体和微生物区系之间的联系，但这是一种 女性生殖道中的未开发区域。我们提出的项目在探索B细胞的作用方面是新颖的 而抗体在调节阴道微生物区系的同时，也在临床上使用利妥昔单抗作为体内的治疗手段 实验模型。这项探索性拨款有可能确定高度重要的生物机制 调节FGT微生物区系和粘膜炎症，两者都与生殖不良有关 健康结果。为了验证我们的假设，我们提出了一项观察性研究，比较了接受 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区系组成中的作用。 在目标1中，我们将比较阴道微生物区系、宫颈免疫细胞、阴道液免疫球蛋白和 接受利妥昔单抗治疗的40名妇女和40名健康对照之间的可溶性炎性标志物。我们会 同时比较服用利妥昔单抗并发炎性阴道炎的妇女和接受利妥昔单抗治疗的妇女之间的这些指标 没有。在目标2中，我们将通过比较我们的B细胞衰竭的变化来评估与B细胞衰竭的因果关系 1)开始使用利妥昔单抗治疗，2)停止使用利妥昔单抗治疗，3)稳定使用利妥昔单抗治疗的女性，随着时间的推移测量分析结果 每组10只。我们当地阴道对免疫细胞群和可溶性标记物的测量将是 与系统测量的B细胞数量和免疫球蛋白水平进行比较。将利妥昔单抗治疗作为一种 活体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。 阴道微生物区系和粘膜免疫反应，这将导致对阴道和 和全身性粘膜免疫。

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.