Rovsing Anne Bruun, Green Kenneth, Jensen Lisbeth, Nielsen Ian Helstrup, Mikkelsen Jacob Giehm, Degn Søren E
Department of Biomedicine, Aarhus University, Aarhus, Denmark.
New York Genome Center, New York, New York, USA.
Scand J Immunol. 2025 Aug;102(2):e70043. doi: 10.1111/sji.70043.
B cells are essential in the immune system, driving antibody production, cytokine secretion and antigen presentation. Studies in mouse models have illuminated key mechanisms underlying B-cell activation, differentiation, class-switch recombination and somatic hypermutation. However, the extent to which these findings translate to human biology remains unclear. To address this, we developed a human primary B-cell culture system using feeder cells engineered to express CD40L, supplemented with the cytokines BAFF, IL-4 and IL-21. Using a Design of Experiments (DOE) approach, we optimised critical parameters and dissected the individual contributions of each specific factor. Our results reveal that BAFF plays a negligible role, and IL-21 has more subtle effects, whereas CD40L and IL-4 are critical determinants of cell viability, proliferation and IgE class-switching. Furthermore, we find that engineered feeder cells can serve equally well as a source of cytokines, but providing these in purified form increases the flexibility of the system. This platform enables detailed investigation of human B-cell biology, offering insights into intrinsic and extrinsic regulators of antibody responses and providing a foundation for in vitro production of human primary antibodies.
B细胞在免疫系统中至关重要，驱动抗体产生、细胞因子分泌和抗原呈递。小鼠模型研究揭示了B细胞激活、分化、类别转换重排和体细胞高频突变的关键机制。然而，这些发现转化到人类生物学中的程度仍不清楚。为了解决这个问题，我们开发了一种人类原代B细胞培养系统，使用经过基因工程改造以表达CD40L的饲养细胞，并补充细胞因子BAFF、IL-4和IL-21。我们采用实验设计（DOE）方法，优化了关键参数并剖析了每个特定因子的单独作用。我们的结果表明，BAFF的作用微不足道，IL-21的影响更为微妙，而CD40L和IL-4是细胞活力、增殖和IgE类别转换的关键决定因素。此外，我们发现工程化饲养细胞作为细胞因子来源同样有效，但以纯化形式提供这些细胞因子可增加系统的灵活性。该平台能够详细研究人类B细胞生物学，深入了解抗体反应的内在和外在调节因子，并为体外生产人类原代抗体奠定基础。
