National Clinical Research Center for Digestive Diseases and Xijing Hospital of Digestive Diseases, Xijing Hospital, Air Force Military Medical University, Xi'an, 710032, China.
BMC Immunol. 2022 Jun 7;23(1):30. doi: 10.1186/s12865-022-00505-4.
Human peripheral blood mononuclear cells (PBMCs) originate from hematopoietic stem cells in the bone marrow, which mainly includes lymphocytes (T cells, B cells, and natural killer cells) and monocytes. Cryopreserved PBMCs providing biobank resources are crucial for clinical application or scientific research. Here, we used flow cytometry to explore the influence of long-term cryopreservation on the quality of PBMCs with the aim of providing important evidence for the effective utilization of biobank resources. The PBMCs were isolated from the peripheral blood, which was collected from volunteers in the hospital. After long-term cryopreservation in liquid nitrogen, we analyzed the changes in cell numbers, viability, and multiple subtypes of PBMCs and studied the apoptosis, proliferation, activation, function, and status of T cells in comparison with freshly isolated PBMCs by flow cytometry, and then further tracked the effects of long-term cryopreservation on the same sample. Although the different cell types in the PBMCs dynamically changed compared with those in the freshly isolated samples, PBMC recovery and viability remained stable after long-term cryopreservation, and the number of most innate immune cells (e.g., monocytes and B cells) was significantly reduced compared to that of the freshly isolated PBMCs or long-term cryopreserved PBMCs; more importantly, the proportion of T cell subtypes, apoptosis, proliferation, and functional T cells, except for Tregs, were not affected by long-term cryopreservation. However, the proportions of activated T, naïve T, central memory T, effector T, and effector memory T cells dynamically changed after long-term cryopreservation. This article provides important evidence for the effective utilization of biobank resources. Long-term cryopreserved PBMCs can be partly used as biological resources for clinical research or basic studies, but the effect of cryopreservation on PBMCs should be considered when selecting cell samples, especially in research relating to activating or inhibiting function.
人外周血单个核细胞（PBMCs）来源于骨髓中的造血干细胞，主要包括淋巴细胞（T 细胞、B 细胞和自然杀伤细胞）和单核细胞。冷冻保存的 PBMCs 为生物银行资源提供了重要的临床应用或科学研究基础。在这里，我们使用流式细胞术来探索长期冷冻保存对 PBMCs 质量的影响，旨在为有效利用生物银行资源提供重要证据。外周血单个核细胞从医院志愿者的外周血中分离出来。经过液氮长期冷冻保存后，我们通过流式细胞术分析了细胞数量、活力和 PBMC 多种亚型的变化，并研究了与新鲜分离的 PBMCs 相比，T 细胞的凋亡、增殖、激活、功能和状态，然后进一步跟踪长期冷冻保存对同一样本的影响。尽管 PBMC 中的不同细胞类型与新鲜分离的样本相比发生了动态变化，但 PBMC 的恢复和活力在长期冷冻保存后保持稳定，与新鲜分离的 PBMCs 或长期冷冻保存的 PBMCs 相比，大多数固有免疫细胞（如单核细胞和 B 细胞）的数量显著减少；更重要的是，除了 Tregs 外，T 细胞亚群、凋亡、增殖和功能 T 细胞的比例不受长期冷冻保存的影响。然而，经过长期冷冻保存后，激活的 T 细胞、幼稚 T 细胞、中央记忆 T 细胞、效应 T 细胞和效应记忆 T 细胞的比例动态发生了变化。本文为有效利用生物银行资源提供了重要证据。长期冷冻保存的 PBMCs 可以部分用作临床研究或基础研究的生物资源，但在选择细胞样本时应考虑冷冻保存对 PBMCs 的影响，特别是在涉及激活或抑制功能的研究中。
