胸腺素α1的研究进展

胸腺素α1(Tα1)是从牛胸腺第五组分(TF5)中提取并纯化具有生物活性的酸性多肽，其分子量为3108，等电点为4．2。Tα1是免疫系统的重要生物调节因子，能促使T细胞的分化及成熟，提高T细胞前体的比率，使白介素—2(IL—2)的生成及高亲和力受体表达增加，提高Th细胞的功能，使机体有效地发挥免疫防护功能。Tα1又能拮抗地塞米松诱导的胸腺细胞亚群的凋亡。临床应用方面，Tα1增强免疫缺陷、自身免疫病以及恶性肿瘤病人的免疫调节作用。Tα1与化疗联合应用能大大增强疗效，降低毒性。本文对Tα1在免疫系统的调节作用及其临床应用方面作一综述。

The development of thymosin alpha 1

Thymosinα(Tα1)is a biologically active polypeptide purified from TF5 and has been completely characterized.It is an acidic peptide with an isoelectric point of 4.2 and a molecular weighy of 3108.Tα1 is considerred as an important bological response modifier which amplifies T-cell immunity.Included in its immunomodulatory properties is the ability to enhance the production of IL-2 and expression of the IL-2 receptor in mitogen-stimulated T-cells.Tα1 also stimulates the differentiation and maturation of T lympocytes,auguments the ratio of pro-T cells and strengthens the function of Th cells,so that the function of immune system can be significantly amplified.Additionally,Tα1 can antagonize dexamethasone-induced apoptosis of subpopulations of thymocytes.In cliniocal trials,thymic hormones strengthen the effects of immnomodulators in immunodeficiencies,autoimmune diseases,and neoplastic malignancies.Combined chemoimmunotherapeutical anti-cancer treatmnet seems to be more efficacious than chemotherapy alone,and the marked hematopoietic toxicity associated with most chemotherapeutical clinical trials can be reduced sighificantly by the addition of immunotherapy.