Porter Amanda P, Pirlot Bonnie M, Dyer Kalyn, Uwazie Crystal C, Nguyen Jimmy, Turner Caitlin, Rajan Devi, Hematti Peiman, Chinnadurai Raghavan
Department of Biomedical Sciences, Mercer University School of Medicine, Savannah, GA, USA.
Department of Medicine, University of Wisconsin Madison, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
Stem Cells. 2022 Dec 31;40(12):1134-1148. doi: 10.1093/stmcls/sxac064.
Cell manufacturing facilities need to define the potency of mesenchymal stromal cells (MSCs) as cellular therapeutics in advanced clinical trials or marketing approval. Since MSCs' mechanism of action in humans is not well defined, more than a single functional property of MSCs needs to be captured as a surrogate measure of potency utilizing assay matrix technologies. However, the current limitation is the sole investigation of MSC-mediated T-cell suppression as a surrogate measure of potency. We investigated the effect of MSCs on B-cell matrix responses to be incorporated into the assay matrix potency analytical system. Our results demonstrate that MSCs inhibit B-cell differentiation and block pan-antibody secretion upon activation of B cells in the PBMCs. In contrast, MSCs are inferior in blocking B-cell matrix responses when purified B cells are used. Mechanistic analysis has demonstrated that MSC-mediated inhibition of B-cell matrix responses is non-contact dependent and Tryptophan metabolic pathway plays a major role, akin to the mechanism of MSC-mediated T-cell suppression. MSCs also inhibit both T-cell and B-cell responses when both of these lymphoid populations are concurrently activated in the PBMCs. Secretome analysis of MSC and T/B cell-activated PBMC cocultures identified direct and inverse correlative matrix signatures between humoral antibody isotypes and secretory molecules. The current analysis of the combined and concomitant investigation of T-cell and B-cell matrix responses fulfills the potency assay matrix strategy by incorporating MSCs' interaction with more than a single inflammatory immune responder.
细胞制造设施需要在晚期临床试验或上市批准中，将间充质基质细胞（MSC）的效力定义为细胞治疗药物。由于MSC在人体内的作用机制尚不明确，因此需要利用检测矩阵技术获取MSC的多种功能特性，作为效力的替代指标。然而，目前的局限性在于仅将MSC介导的T细胞抑制作用作为效力的替代指标进行研究。我们研究了MSC对B细胞基质反应的影响，以便将其纳入检测矩阵效力分析系统。我们的结果表明，MSC可抑制PBMC中B细胞活化后的分化，并阻断全抗体分泌。相比之下，当使用纯化的B细胞时，MSC在阻断B细胞基质反应方面效果较差。机制分析表明，MSC介导的对B细胞基质反应的抑制不依赖细胞接触，色氨酸代谢途径起主要作用，这与MSC介导的T细胞抑制机制类似。当PBMC中的T细胞和B细胞同时被激活时，MSC也会抑制这两种淋巴细胞的反应。对MSC与T/B细胞激活的PBMC共培养物的分泌组分析确定了体液抗体同种型与分泌分子之间直接和反向相关的基质特征。目前对T细胞和B细胞基质反应的联合及同步研究分析，通过纳入MSC与多种炎症免疫反应细胞的相互作用，实现了效力检测矩阵策略。
