Mast Cell Biology Section, Laboratory of Allergic Diseases, Bethesda, MD 20892, USA.
AIDS Research Review Branch/SRP, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Int J Mol Sci. 2019 Nov 6;20(22):5520. doi: 10.3390/ijms20225520.
Laboratory of allergic diseases 2 (LAD2) human mast cells were developed over 15 years ago and have been distributed worldwide for studying mast cell proliferation, receptor expression, mediator release/inhibition, and signaling. LAD2 cells were derived from CD34+ cells following marrow aspiration of a patient with aggressive mastocytosis with no identified mutations in . Another aspiration gave rise to a second cell line which has recently been re-established (LADR). We queried whether LADR had unique properties for the preclinical study of human mast cell biology.
LADR and LAD2 cells were cultured under identical conditions. Experiments examined proliferation, beta-hexosaminidase (β-hex) release, surface receptor and granular protease expression, infectivity with HIV, and gene expression.
LADR cells were larger and more granulated as seen with Wright-Giemsa staining and flow cytometry, with cell numbers doubling in 4 weeks, in contrast to LAD2 cells, which doubled every 2 weeks. Both LADR and LAD2 cells released granular contents following aggregation of FcεRI. LADR cells showed log-fold increases in FcεRI/CD117 and expressed CD13, CD33, CD34, CD63, CD117, CD123, CD133, CD184, CD193, and CD195, while LAD2 cells expressed CD33, CD34, CD63, CD117, CD133, CD193 but not CD13, CD123, CD184, or CD195. LADR tryptase expression was one-log-fold increased. LADR cell and LAD2 cell chymase expression were similar. Both cell lines could be infected with T-tropic, M-tropic, and dual tropic HIV. Following monomeric human IgE stimulation, LADR cells showed greater surface receptor and mRNA expression for CD184 and CD195. Expression arrays revealed differences in gene upregulation, especially for the suppressor of cytokine signaling (SOCS) family of genes with their role in JAK2/STAT3 signaling and cellular myeloytomatosis oncogene (c-MYC) in cell growth and regulation.
LADR cells are thus unique in that they exhibit a slower proliferation rate, are more advanced in development, have increased FcεRI/CD117 and tryptase expression, have a different profile of gene expression, and show earlier infectivity with HIV-BAL, LAV, and TYBE when compared to LAD2 cells. This new cell line is thus a valuable addition to the few FcεRI+ human mast cell lines previously described and available for scientific inquiry.
过敏性疾病 2 号实验室（LAD2）人肥大细胞是 15 多年前开发的，并已在全球范围内分发，用于研究肥大细胞增殖、受体表达、介质释放/抑制和信号转导。LAD2 细胞源自一名患有侵袭性肥大细胞增多症的患者的骨髓抽吸物，该患者的中未发现突变。另一次抽吸产生了第二个细胞系，该细胞系最近已被重新建立（LADR）。我们询问 LADR 是否具有独特的特性，用于人类肥大细胞生物学的临床前研究。
LADR 和 LAD2 细胞在相同条件下培养。实验研究了增殖、β-己糖胺酶（β-hex）释放、表面受体和颗粒蛋白酶表达、HIV 感染和基因表达。
LADR 细胞用 Wright-Giemsa 染色和流式细胞术观察到更大和更颗粒状，细胞数量在 4 周内翻了一番，而 LAD2 细胞每两周翻一番。LADR 和 LAD2 细胞在 FcεRI 聚集后均释放颗粒内容物。LADR 细胞的 FcεRI/CD117 对数倍增加，并表达 CD13、CD33、CD34、CD63、CD117、CD123、CD133、CD184、CD193 和 CD195，而 LAD2 细胞仅表达 CD33、CD34、CD63、CD117、CD133、CD193，而不表达 CD13、CD123、CD184 或 CD195。LADR 类胰蛋白酶表达增加了一个对数倍。LADR 细胞和 LAD2 细胞糜蛋白酶表达相似。两种细胞系均可感染 T 嗜性、M 嗜性和双嗜性 HIV。在单体人 IgE 刺激后，LADR 细胞表面受体和 CD184 和 CD195 的 mRNA 表达增加。表达谱显示基因上调的差异，特别是细胞因子信号转导抑制因子（SOCS）家族的基因，其在 JAK2/STAT3 信号转导和细胞髓样细胞瘤癌基因（c-MYC）在细胞生长和调节中发挥作用。
因此，LADR 细胞是独特的，因为它们表现出较慢的增殖速度，发育更成熟，FcεRI/CD117 和类胰蛋白酶表达增加，基因表达谱不同，与 LAD2 细胞相比，它们更早感染 HIV-BAL、LAV 和 TYBE。这种新的细胞系是对以前描述和可用于科学研究的少数 FcεRI+人肥大细胞系的有价值的补充。
