Department of Urology, Comprehensive Cancer Center Innsbruck, Medical University of Innsbruck, Innsbruck, Austria.
Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.
Front Immunol. 2023 Jul 13;14:1202157. doi: 10.3389/fimmu.2023.1202157. eCollection 2023.
BCG is the most efficient adjuvant therapy for high-risk, non-muscle-invasive bladder cancer (NMIBC). Both innate and adaptive immune responses have been implicated in BCG-mediated effects. BCG vaccination can boost innate immune responses via trained immunity (TI), resulting in an increased resistance to respiratory viral infections. Here we evaluated for the first time whether intravesical application of BCG triggers increased immunity against SARS-CoV-2 in patients with high-risk NMIBC. Serum and peripheral blood mononuclear cells (PBMCs) from heparinized whole blood samples of 11 unvaccinated SARS-CoV-2-naïve high-risk NMIBC patients were collected at baseline and during BCG treatment in a pre-COVID-19 era. To examine B-cell or T cell-dependent adaptive immunity against SARS-CoV-2, sera were tested for the presence of SARS-CoV-2 neutralizing antibodies. Using a SARS-CoV-2 peptide pool, virus-specific T cells were quantified via IFNγ ELISpot assays. To analyze innate immune responses, mRNA and protein expression levels of pro- and anti-inflammatory cytokines were measured after a 24-hour stimulation of PBMCs with either BCG or SARS-CoV-2 wildtype. ATAC- sequencing was performed to identify a potential epigenetic reprogramming in immune cells. We neither identified SARS-CoV-2 neutralizing antibodies nor SARS-CoV-2- reactive T cells, indicating that intravesical BCG did not induce adaptive immunity against SARS-CoV-2. However, a significant increase in mRNA as well as protein expression of IL-1β, IL-6 and TNFα, which are key cytokines of trained immunity, could be observed after at least four intravesical BCG instillations. Genomic regions in the proximity of TI genes (, , ) were more accessible during BCG compared to baseline. Although intravesical BCG did not induce adaptive immune responses, repetitive intravesical instillations of BCG induced circulating innate immune cells that produce TI cytokines also in response to SARS-CoV-2.
BCG 是高危非肌肉浸润性膀胱癌（NMIBC）最有效的辅助治疗方法。先天和适应性免疫反应都与 BCG 介导的作用有关。BCG 疫苗接种可以通过训练有素的免疫（TI）增强先天免疫反应，从而增加对呼吸道病毒感染的抵抗力。在这里，我们首次评估了膀胱内应用 BCG 是否会在高危 NMIBC 患者中引发针对 SARS-CoV-2 的增强免疫力。在 COVID-19 之前的时期，从 11 名未接种 SARS-CoV-2 的高危 NMIBC 患者的肝素化全血样本的血清和外周血单核细胞（PBMC）中采集基线和 BCG 治疗期间的样本。为了检查针对 SARS-CoV-2 的 B 细胞或 T 细胞依赖性适应性免疫，检测血清中是否存在 SARS-CoV-2 中和抗体。使用 SARS-CoV-2 肽池，通过 IFNγ ELISpot 测定来定量病毒特异性 T 细胞。为了分析先天免疫反应，在 PBMC 用 BCG 或 SARS-CoV-2 野生型刺激 24 小时后，测量促炎和抗炎细胞因子的 mRNA 和蛋白表达水平。进行 ATAC- 测序以鉴定免疫细胞中潜在的表观遗传重编程。我们既没有发现 SARS-CoV-2 中和抗体，也没有发现 SARS-CoV-2 反应性 T 细胞，这表明膀胱内 BCG 并未诱导针对 SARS-CoV-2 的适应性免疫。然而，在至少进行四次膀胱内 BCG 滴注后，IL-1β、IL-6 和 TNFα 的 mRNA 以及蛋白表达水平显著增加，这些细胞因子是训练有素的免疫的关键细胞因子。与基线相比，在 BCG 时 TI 基因（、、）附近的基因组区域更容易接近。尽管膀胱内 BCG 未诱导适应性免疫反应，但重复的膀胱内 BCG 滴注诱导产生 TI 细胞因子的循环先天免疫细胞也可响应 SARS-CoV-2。
