Montgomery D W, LeFevre J A, Ulrich E D, Adamson C R, Zukoski C F
Department of Pharmacology, University of Arizona College of Medicine, Tucson 85724.
Endocrinology. 1990 Nov;127(5):2601-3. doi: 10.1210/endo-127-5-2601.
Cultured murine lymphoid cells release a PRL-like immunoreactive (IR) protein which may be important in immunity, as anti-PRL antisera inhibit lymphocyte proliferation in vitro. We examined culture supernatants (SNs) and cell lysates from concanavalin A (Con A) activated murine thymocytes to identify these proteins. Western blot analysis of cell lysates revealed three specifically-stained PRL-IRs. A doublet of bands at 35.6 and 33.6 kDa was associated with the particulate fraction of the cell. These PRL-IRs were present in lymphocytes independently of mitogen stimulation. In contrast, a 22 kDa PRL-IR was only produced in mitogen stimulated cells, and was specifically immunoprecipitated with anti-PRL antiserum. In addition, all three PRL-like IRs incorporated 35S-methionine in vitro, indicating that they are synthesized by these cells. Only the 22 kDa PRL-like protein was present in culture medium from stimulated cells, suggesting that this may be the PRL bioactivity previously demonstrated in SNs from murine lymphocytes.
培养的小鼠淋巴细胞释放一种催乳素样免疫反应性（IR）蛋白，其可能在免疫中起重要作用，因为抗催乳素抗血清在体外抑制淋巴细胞增殖。我们检测了伴刀豆球蛋白A（Con A）激活的小鼠胸腺细胞的培养上清液（SNs）和细胞裂解物，以鉴定这些蛋白。细胞裂解物的蛋白质印迹分析显示出三条特异性染色的催乳素-IR。35.6 kDa和33.6 kDa处的双条带与细胞的颗粒部分相关。这些催乳素-IR独立于有丝分裂原刺激存在于淋巴细胞中。相比之下，22 kDa的催乳素-IR仅在有丝分裂原刺激的细胞中产生，并且被抗催乳素抗血清特异性免疫沉淀。此外，所有三种催乳素样IR在体外都掺入了35S-甲硫氨酸，表明它们是由这些细胞合成的。仅22 kDa的催乳素样蛋白存在于刺激细胞的培养基中，这表明这可能是先前在小鼠淋巴细胞的SNs中证明的催乳素生物活性。
