Immunization of Male Mice with a New Recombinant GnRH Fusion Protein Reduces the Testicular Function

• Published in: Agricultural sciences in China Vol. 8; no. 3; pp. 380 - 385
• Main Authors: FANG, Fu-gui, YANG, Ya-ping, LIU, Ya, ZHANG, Yun-hai, TAO, Yong, WANG, Suo-lu, PU, Yong, ZHANG, Xiao-rong
• Format: Journal Article
• Language: English
• Published: Departraent of Animal Medicine, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, P,R.China%Department of Aniraal Science, College of Aniraal Science and Technology, Anhui Agricultural University, Hefei 230036, P.R.China 01.03.2009
• Subjects: 促性腺激素释放激素; 蛋白激素; 融合蛋白; 间接酶联免疫吸附试验; 雄性小鼠; 麦芽糖结合蛋白; recombinant; vaccine; immunocastration; maltose-binding protein (MBP); GnRH
• ISSN: 1671-2927
• DOI: 10.1016/S1671-2927(08)60222-9

The objective of the present study was to evaluate the effect of an immunogenic maltose-binding protein-gonadotropin releasing hormone （GnRH-6-MBP） using genetic engineering. The synthetic mammalian tandem repeated GnRH hexamer gene was inserted into the expression plasmid pMAL-c2x. Recombinant GnRH-6-MBP protein was over- expressed in E.coli strain BL21. Amylose resin with affinity chromatograph was used to purify target protein. The reactiongenicity of fusion protein was identified by indirect enzyme linked immunosorbent assay （ELISA）, and the antigenicity and biological effects of GnRH-6-MBP were tested in mice. In the experiment, 20 male Kunming white mice of 20 d old were randomly divided into treatment and control group. Ten mice were immunized with 100 μg GnRH-6-MBP administered subcutaneously （s.c.） thrice at 2-week intervals with GnRH-6-MBP. Mice were sacrificed after 3 weeks following the booster injection, the testis was removed, weighed and measured, and the histological structure was observed. The reactiongenicity of fusion protein to GnRH antibody was much higher than the control. Active immunization against GnRH-6-MBP reduced remarkably （P 〈 0.01） the length and weight of the testis, and shortened the girth and width of the testis （P 〈 0.05）, and suppressed testicular spermatogenesis compared to the control mice. These results indicate that the recombinant GnRH-6-MBP acted as a strong immunogen and caused atrophy of the testis.