Absolute macrophage dependency of T lymphocyte activation by mitogens.
Absolute macrophage dependency of T lymphocyte activation by mitogens.
复制标题
有丝分裂原对 T 淋巴细胞激活的绝对巨噬细胞依赖性。
作者：
D. Rosenstreich;J. Farrar;S. Dougherty
用两种不同类型的粘附柱从豚鼠淋巴结细胞中制备了仅含0.3%巨噬细胞和少于2% B淋巴细胞的T淋巴细胞亚群。除非加入额外的巨噬细胞，否则该亚群不响应于有丝分裂原Con A或PHA而增殖。已经研究了巨噬细胞恢复T细胞对PHA的反应性的方法。在这种实验情况下，巨噬细胞似乎通过两种不同的机制发挥作用。第一种机制涉及PHA与巨噬细胞的结合，然后以诱导细胞活化的方式将有丝分裂原"呈递"给T淋巴细胞。这种呈递功能要求巨噬细胞具有活力和代谢活性。巨噬细胞发挥功能的第二种机制是通过一种或多种可溶性因子的加工。这些因子的存在已通过使用双室Marbrook型组织培养容器得到可靠且可重复的证明。这种可溶性因子可以在明显缺乏任何形式的巨噬细胞呈递的情况下用表面结合的PHA诱导T巨噬细胞的活化。相反，该因子的功能明显不同于还原剂2-巯基乙醇（2-ME）的功能，因为2-ME不能使该T细胞亚群被有丝分裂原激活。根据这些观察，我们提出，需要两个不同的信号来激活这个T淋巴细胞亚群。一种信号通过有丝分裂原与T细胞表面的相互作用传递，第二种信号通过巨噬细胞产生的可溶性因子传递。是否所有类型的T淋巴细胞都需要两种信号才能被激活，仍有待确定。
A T lymphocyte subpopulation that contains only 0.3% macrophages and less than 2% B lymphocytes has been prepared from guinea pig lymph node cells by the use of two different types of adherence columns. This subpopulation does not porliferate in response to the mitogens Con A or PHA unless additional macrophages are added. The means by which macrophages restore T cell responsiveness to PHA has been investigated. Marcophages appear to function via two different distinct mechanisms in this experimental situation. The first mechanism involves the binding of PHA to the macrophage followed by the "presentation" of the mitogen to the T lymphocyte in a manner that induces cell activation. This presentation function requires that the macrophage be viable and metabolically active. The second mechanism by which macrophages function is by the elaboration of a soluble factor or factors. The presence of these factors has been reliably and reproducibly demonstrated by using a double-chambered, Marbrook-type tissue culture vessel. This soluble factor can induce activation of T lympohcytes with surface bound PHA in the apparent absence of any form of macrophage presentation. In contrast, the function of this factor is clearly distinct from that of the reducing agent, 2-mercaptoethanol, (2-ME) since 2-ME does not enable this T cell subpopulation to be activated by mitogens. On the basis of these observations, we propose that two distinct signals are required to activate this T lymphocyte subpopulation. One signal is delivered by the interaction of the mitogen with the T cell surface, and the second signal is delivered by a soluble factor(s) produced by macrophages. Whether all types of T lymphocytes require two signals to be activated, remains to be established.