Mercure L, Tannenbaum G S, Schipper H M, Phaneuf D, Wainberg M A
McGill University AIDS Centre, Montreal, Quebec, Canada.
Clin Diagn Lab Immunol. 1996 Mar;3(2):151-5. doi: 10.1128/cdli.3.2.151-155.1996.
Somatostatin (somatotropin release-inhibiting hormone; SRIH) has been demonstrated in neurons of the central nervous system (CNS) as well as in endocrine cells of the pancreas and gastrointestinal tract and can suppress various immune functions including lymphocyte proliferation, immunoglobulin synthesis, and cytokine production. Since astrocytes possess antigen-presenting activity and can secrete a wide array of immunoregulatory and inflammatory cytokines, we studied SRIH gene expression in both astrocyte cell lines and mitogen-stimulated peripheral blood mononuclear leukocytes from healthy donors. We now report by means of a complementary DNA-based reverse transcription PCR that differential levels of SRIH mRNA were expressed in 9 of 11 human astrocytoma cell lines tested but were undetectable in activated peripheral blood mononuclear leukocytes as well as in a variety of human lymphocyte and monocyte cell lines. The synthesis and secretion of SRIH protein by astrocytoma cells that expressed SRIH transcripts were confirmed by specific radioimmunoassay of cell culture fluids. These findings support the notion that SRIH gene expression occurs in human astrocytoma cells but not in mature lymphoid cells of the immune system.
生长抑素（促生长激素释放抑制激素；SRIH）已在中枢神经系统（CNS）的神经元以及胰腺和胃肠道的内分泌细胞中得到证实，并且可以抑制多种免疫功能，包括淋巴细胞增殖、免疫球蛋白合成和细胞因子产生。由于星形胶质细胞具有抗原呈递活性，并且可以分泌多种免疫调节和炎性细胞因子，我们研究了星形胶质细胞系以及来自健康供体的丝裂原刺激的外周血单个核白细胞中SRIH基因的表达。我们现在通过基于互补DNA的逆转录PCR报告，在所测试的11个人星形细胞瘤细胞系中的9个中表达了不同水平的SRIH mRNA，但在活化的外周血单个核白细胞以及各种人淋巴细胞和单核细胞系中未检测到。通过对细胞培养液进行特异性放射免疫测定，证实了表达SRIH转录本的星形细胞瘤细胞合成和分泌了SRIH蛋白。这些发现支持以下观点：SRIH基因表达发生在人星形细胞瘤细胞中，而不是免疫系统的成熟淋巴细胞中。
