Department of Gastroenterological and Transplant Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Molecular Diagnostics Division, Wakunaga Pharmaceutical Co., Ltd., Osaka, Japan.
PLoS One. 2021 Feb 5;16(2):e0236614. doi: 10.1371/journal.pone.0236614. eCollection 2021.
In organ transplantation, human leukocyte antigen (HLA)-mismatch grafts not only induce the activation of cellular mediated immune response but also the development of chronic antibody-mediated rejection due to the donor-specific anti-HLA antibody (DSA) produced by B cells and plasma cells interacting with the graft endothelium. Significant improvement in long-term survival after transplantation can be expected if antibody-mediated rejection due to the DSA can be overcome. However, the mechanism of producing or controlling the DSA remains to be elucidated. In recent decades, "humanized" mouse models have been widely used for the basic research of human immune systems, but a humanized mouse model to analyze the mechanism of DSA production has not been established yet. Thus, we aimed to create a humanized mouse using a severe immunodeficiency mouse (NSG mouse) administered with human peripheral blood mononuclear cells (PBMCs). Initially, we detected a very low level of human total-IgG and no anti-HLA antibodies (Abs) in these mice. In our next attempt, we mixed PBMCs of various HLA antigenic combinations with or without regulatory T cells and preconditioned them by culturing on feeder cells stably transfected with human CD40 ligand (h-CD40L) alone or with h-CD40L and human B cell activating factor (h-BAFF). They were subsequently co-cultured with the corresponding irradiated stimulator PBMCs, and all cells were administered into naïve NSG mice. Although all three humanized models had sufficient human total-IgG and anti-HLA antibody production, allospecific anti-HLA Ab production was prominently suppressed whereas non-specific anti-HLA Abs were sufficiently detected. Therefore, this novel humanized mouse model might be useful for analyzing the mechanism of anti-allogeneic human B cell tolerance induction.
在器官移植中，人类白细胞抗原（HLA）不匹配的移植物不仅会诱导细胞介导的免疫反应的激活，还会由于 B 细胞和浆细胞产生的供体特异性抗 HLA 抗体（DSA）与移植物内皮相互作用而导致慢性抗体介导的排斥反应。如果能够克服 DSA 引起的抗体介导的排斥反应，移植后的长期生存率有望显著提高。然而，产生或控制 DSA 的机制仍有待阐明。近几十年来，“人源化”小鼠模型已广泛应用于人类免疫系统的基础研究，但尚未建立用于分析 DSA 产生机制的人源化小鼠模型。因此，我们旨在使用严重免疫缺陷小鼠（NSG 小鼠）给予人外周血单核细胞（PBMC）来创建人源化小鼠。最初，我们在这些小鼠中检测到非常低水平的人总 IgG 和无抗 HLA 抗体（Abs）。在我们的下一次尝试中，我们将各种 HLA 抗原组合的 PBMC 与或不与调节性 T 细胞混合，并通过在单独或与 h-CD40L 和人 B 细胞激活因子（h-BAFF）稳定转染的饲养细胞上培养来对其进行预处理。随后，将它们与相应的辐照刺激 PBMC 共培养，并将所有细胞给予幼稚的 NSG 小鼠。尽管所有三种人源化模型都具有足够的人总 IgG 和抗 HLA 抗体产生能力，但同种异体抗 HLA Ab 的产生受到明显抑制，而非特异性抗 HLA Abs 则得到充分检测。因此，这种新型人源化小鼠模型可能有助于分析抗同种异体人 B 细胞耐受诱导的机制。
