TY  - EJOU
AU  - XIAO-MING*, CHEN FENG*, CHEN XIANG-MING**, CHEN ZHI*, JIANG HAN-LIANG*, PAN XIAO-PING*, HU ZHONG-RONG*, LIU RONG-HUA*, CHEN 

TI  - Construction and application of a yeast expression system for thymosin α1
T2  - BIOCELL

PY  - 2005
VL  - 29
IS  - 3
SN  - 1667-5746

AB  - We want to construct a yeast expression system for thymosin α1 (Tα1) to make the orally administered Tα1 preparation possible. The whole Tα1 DNA fragment was obtained by PCR. After being digested with restriction enzymes, it was cloned into pYES2 vector. Sequencing was performed to identify the recombinant. The sequence of Tα1 in recombinant coincided with the original one reported in Genbank. When pYES2-Tα1 plasmid was transformed into yeast, galactose instead of glucose was used to induce Tα1 expression. Western blot was performed to identify the quality of the expressed Tα1. Dried yeast containing pYEST2-Tα1 was fed to Balb/c mice whose immunities were inhibited by cyclophosphamide in advance. Synthesized Tα1 peptide was used as positive control and empty yeast was used as negative control. Compared with the negative control group, both dried yeast containing pYEST2-Tα1 and synthesized Tα1 peptide can significantly increase the CD8+ level (22.74±1.09 and 18.77±4.72 vs 7.49±2.14, <i>p</i><0.01), while both of them had little effect on the CD4+ lymphocytes (61.86±6.94 and 65.91±4.78 vs 57.93±10.40, <i>p</i>>0.05). We concluded that a high effective yeast expression system for Tα1 was constructed successfully and the Tα1 protein expressed by this system can improve CD8+ level in immune inhibited mice.
KW  - thymosin α1
KW  -  yeast expression system
KW  -  biological activity
KW  -  orally administered

DO  - 10.32604/biocell.2005.29.253