Bates L G, Grove D S, Mastro A M
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802, USA.
Exp Cell Res. 1995 Jun;218(2):567-72. doi: 10.1006/excr.1995.1192.
Rat Nb 2 lymphoma cells have been widely used to bioassay human growth hormone and many species of prolactin. Because their morphologic characterization suggests a T-cell lineage, Nb 2 cells were examined for their response to the T-cell mitogens concanavalin A, pokeweed mitogen, and phytohemagglutinin P. As expected, a dose-response to rat prolactin was observed; however, attempts to induce proliferation using the conventional T-cell mitogens failed at concentrations normally stimulatory for rat primary lymphocytes. Moreover, when Nb 2 cells were simultaneously incubated with lectin plus a suboptimal concentration of prolactin, a dose-dependent suppression of the stimulatory effects of prolactin was observed with phytohemagglutinin P and pokeweed mitogen, although not with concanavalin A. Culture medium of prolactin-stimulated Nb 2 cells also contained a factor which inhibited normal rat lymphocyte activation by concanavalin A. The factor did not block induction of the IL-2 receptor and proliferation of IL-2-dependent CTLL-2 cells could be restored by exogenous IL-2. Because Nb 2 cells evolved from a lactogen-dependent lymph node tumor, these results may have implications for further understanding the role of pituitary hormones, particularly prolactin, in the immune response to hormone-dependent tumor progression.
大鼠Nb 2淋巴瘤细胞已被广泛用于生物测定人生长激素和多种催乳素。由于其形态学特征提示为T细胞谱系，因此检测了Nb 2细胞对T细胞丝裂原刀豆球蛋白A、商陆丝裂原和植物血凝素P的反应。正如预期的那样，观察到了对大鼠催乳素的剂量反应；然而，在通常对大鼠原代淋巴细胞有刺激作用的浓度下，使用传统T细胞丝裂原诱导增殖的尝试失败了。此外，当Nb 2细胞与凝集素以及次优浓度的催乳素同时孵育时，观察到植物血凝素P和商陆丝裂原对催乳素刺激作用有剂量依赖性抑制，而刀豆球蛋白A则没有。催乳素刺激的Nb 2细胞的培养基中还含有一种因子，该因子可抑制刀豆球蛋白A对正常大鼠淋巴细胞的激活。该因子不会阻断IL-2受体的诱导，外源性IL-2可恢复IL-2依赖的CTLL-2细胞的增殖。由于Nb 2细胞源自依赖催乳素的淋巴结肿瘤，这些结果可能对进一步理解垂体激素，特别是催乳素，在对激素依赖性肿瘤进展的免疫反应中的作用具有启示意义。
