Rosenzweig M, Marks D F, Zhu H, Hempel D, Mansfield K G, Sehgal P K, Kalams S, Scadden D T, Johnson R P
Division of Immunology, New England Regional Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA.
Blood. 1996 May 15;87(10):4040-8.
Differentiation of hematopoietic progenitor cells into T lymphocytes generally occurs in the unique environment of the thymus, a feature that has hindered efforts to model this process in the laboratory. We now report that thymic stromal cultures from rhesus macaques can support T-cell differentiation of human or rhesus CD34+ progenitor cells. Culture of rhesus or human CD34+ bone marrow-derived cells depleted of CD34+ lymphocytes on rhesus thymic stromal monolayers yielded CD3+CD4+CD8+, CD3+CD4+CD8-, and CD3+CD4-CD8+ cells after 10 to 14 days. In addition to classical T lymphocytes, a discrete population of CD3+CD8loCD16+CD56+ cells was detected after 14 days in cultures inoculated with rhesus CD34+ cells. CD3+ T cells arising from these cultures were not derived from contaminating T cells present in the CD34+ cells used to inoculate thymic stromal monolayers or from the thymic monolayers, as shown by labeling of cells with the lipophilic membrane dye PKH26. Expression of the recombinase activation gene RAG-2, which is selectively expressed in developing lymphocytes, was detectable in thymic cultures inoculated with CD34+ cells but not in CD34+ cells before thymic culture or in thymic stromal monolayers alone. Reverse transcriptase-polymerase chain reaction analysis of T cells derived from thymic stromal cultures of rhesus and human CD34+ cells showed a polyclonal T-cell receptor repertoire. T-cell progeny derived from rhesus CD34+ cells cultured on thymic stroma supported vigorous simian immunodeficiency virus replication in the absence of exogenous mitogenic stimuli. Rhesus thymic stromal cultures provide a convenient means to analyze T-cell differentiation in vitro and may be useful as a model of hematopoietic stem cell therapy for diseases of T cells, including acquired immunodeficiency syndrome.
造血祖细胞分化为T淋巴细胞通常发生在胸腺这个独特的环境中，这一特性阻碍了在实验室模拟该过程的努力。我们现在报告，恒河猴的胸腺基质培养物能够支持人或恒河猴CD34⁺祖细胞的T细胞分化。将恒河猴或人CD34⁺骨髓来源的细胞中耗尽CD34⁺淋巴细胞后，在恒河猴胸腺基质单层上培养，10至14天后产生了CD3⁺CD4⁺CD8⁺、CD3⁺CD4⁺CD8⁻和CD3⁺CD4⁻CD8⁺细胞。除了经典的T淋巴细胞外，在用恒河猴CD34⁺细胞接种的培养物中，14天后检测到了一群离散的CD3⁺CD8loCD16⁺CD56⁺细胞。如用亲脂性膜染料PKH26标记细胞所示，这些培养物产生的CD3⁺T细胞并非来自接种胸腺基质单层的CD34⁺细胞中存在的污染性T细胞或胸腺单层。重组酶激活基因RAG-2在发育中的淋巴细胞中选择性表达，在用CD34⁺细胞接种的胸腺培养物中可检测到其表达，但在胸腺培养前的CD34⁺细胞或单独的胸腺基质单层中未检测到。对来自恒河猴和人CD34⁺细胞胸腺基质培养物的T细胞进行逆转录酶-聚合酶链反应分析，显示出多克隆T细胞受体库。在没有外源性促有丝分裂刺激的情况下，在胸腺基质上培养的恒河猴CD34⁺细胞衍生的T细胞后代支持强烈的猴免疫缺陷病毒复制。恒河猴胸腺基质培养物提供了一种在体外分析T细胞分化的便捷方法，并且可能作为治疗包括获得性免疫缺陷综合征在内的T细胞疾病的造血干细胞治疗模型。
