Norton James E, Kommineni Sushma, Akrivoulis Patricia, Gutierrez Dario A, Hazuda Daria J, Swaminathan Gokul
Exploratory Science Center, MRL, Merck & Co., Inc., Cambridge, MA 02141, USA.
Vaccines (Basel). 2021 Mar 5;9(3):225. doi: 10.3390/vaccines9030225.
There is mounting evidence that the microbiome plays a critical role in training and maturation of the host immune system. Pre-clinical and clinical studies have shown that microbiome perturbation is correlated with sub-optimal host responses to vaccines and cancer immunotherapy. As such, identifying species of commensal bacteria capable of modulating immunological outcomes is of considerable interest. Currently, the lack of reliable primary immune cell-based assays capable of differentiating immuno-modulatory properties of various commensal bacteria is a major limitation. Here, we demonstrate that primary human monocyte-derived dendritic cells (MoDC) are capable of stratifying different strains of live and heat-killed commensal bacteria in an in vitro culture system. Specifically, heat-killed bacterial strains were able to differentially modulate co-stimulation/maturation markers CD80, CD83, and HLA-DR, as well as cytokine/chemokine signatures, such as IL-1b, MIP-1a, and TNFa in primary human MoDC. We further validated our observations using the TruCulture (Myriad RBM, Inc., Austin, TX, USA) whole-blood ex vivo culture system. Using this ex vivo system allowed us to measure immune-altering effects of commensal bacteria in primary human whole-blood. As such, we report that both these primary in vitro and ex vivo systems are robust and enable identification, stratification, and differentiation of various commensal bacteria as potential modulators of host immunity.
越来越多的证据表明，微生物群在宿主免疫系统的训练和成熟过程中起着关键作用。临床前和临床研究表明，微生物群的扰动与宿主对疫苗和癌症免疫疗法的次优反应相关。因此，识别能够调节免疫结果的共生细菌种类具有相当大的研究意义。目前，缺乏可靠的基于原代免疫细胞的检测方法来区分各种共生细菌的免疫调节特性是一个主要限制。在此，我们证明原代人单核细胞衍生的树突状细胞（MoDC）能够在体外培养系统中对不同菌株的活的和热灭活的共生细菌进行分层。具体而言，热灭活的细菌菌株能够差异性地调节共刺激/成熟标志物CD80、CD83和HLA-DR，以及细胞因子/趋化因子特征，如原代人MoDC中的IL-1b、MIP-1a和TNFa。我们使用TruCulture（美国得克萨斯州奥斯汀市Myriad RBM公司）全血体外培养系统进一步验证了我们的观察结果。使用这种体外系统使我们能够测量共生细菌对原代人全血的免疫改变作用。因此，我们报告这两种原代体外和体外系统都很强大，能够识别、分层和区分各种共生细菌作为宿主免疫的潜在调节因子。
