Effect Of Active Immunization Against Three Recombinant Proteins Produced By Gene Transfer Based On The MSTN Mature Region Of Xiaomeishan Swine On The Growth Of Mice

1 Background and AimsMyostatin (also called growth and differentiation factor-8, GDF-8) was recently identified as a member of the TGF-βsuperfamily that acts as a potent and specific negative regulator of skeletal muscle mass. Homozygous disruption of the myostatin gene in mice results in a significant increase in skeletal muscle mass and a reduction in body fat. Naturally occurring myostatin mutations in cattle display a similar double-muscled phenotype, confirming a role for myostatin in muscle development and regulation. Blocking myostatin activity may have the development of novel muscle enhancing agents for both the therapy for the human diseases such as HIV infects and agricultural applications.In order to find an efficient vaccine to promote the muscle growth and investigate the feasibility of improving the muscle quality using protein vaccine related to MSTN, this research expresses three kinds of prokaryotic proteins which are designed based on the MSTN mature region. These proteins are then used to immunize the mice respectively, after that we obtain the serum, observe and analyze the data which is related to growth performance. All this we have done may provide a base for the study on promoting animal muscle growth by immunifaction of MSTN.2 Methods and ResultsFist, we amplify the mature region of MSTN gene in Xiaomeishan swine using PCR method, then we bond the universal T cell epitopes(TT/PADRE) to the N-terminatio of the mature MSTN using the linker (GGGS), after that we construct the clonal and expressing vector of MSTN, TT-MSTN, PD-MSTN. We transfect these expression vectors into BL21, after inducing the BL21, we extract and identify the fusion proteins. The MSTN, TT-MSTN, PD-MSTN fusion proteins are used as candidate vaccines to immunize the mice respectively with adjuvant. During this period, we collect the serum of the mice, test the serum antibody titer using the ELISA method, measure and analyze the weight of body, carcass, pectoralis major, quadriceps femoris, biceps femoris, gastrocnemius and non-esterified fatty acid in belly cavity, account the feed to gain ratio. After all of the research, we find that: we have constructed MSTN, TT-MSTN and PD-MSTN expression vectors successfully and correctly, completed the expression and identification of these fusion proteins, produced these proteins abundance; All of these candidate vaccines can induced high tite specificity neutralization antibody against MSTN in immunized mice, the TT-MSTN, PD-MSTN can induce higher tite than the MSTN (tite>5×103); All these vaccines can promote the growth of muscular tissue in different extent and the TT-MSTN is more efficient; the TT-MSTN can enhance the growth of mice and degrade the ratio of feed to gain, but the effect isn't significant compared with other groups.3 ConclusionsWe have constructed three candidate protein vaccines and systemically compared the immune effect of these candidate myostatin protein vaccines. The research proves that the T cell epitopes: TT_830-844, PDARE can boost the immunogenicity of auto-vaccine and the TT-MSTN has more ascendant not only in promoting muscle growth but also in improving the efficiency of raising. The research of myostatin auto-vaccine provides a new approach for improving the muscle weight of poultry and livestock in stockbreeding and for treatment in muscle related disease in medical domain.