Wang B S, Lumanglas A A, Shieh H M, Corbett M J, Zhang R J, Kraft L A
Laboratory of Immunoendocrinology, Cyanamid Agricultural Research Center, Princeton, NJ 08543-0400, USA.
Mol Immunol. 1996 May-Jun;33(7-8):609-14. doi: 10.1016/0161-5890(96)00023-5.
A mouse monoclonal antibody (mAb), designated PS-7.6, was previously shown to enhance the activity of porcine growth hormone (pGH) in promoting the growth of hypophysectomized (hypox) rats. Epitope mapping studies indicated that the region recognized by PS-7.6 resided within an amino acid sequence 54-95 of pGH. A peptide corresponding to this sequence was synthesized and found to induce swine antibodies capable of augmenting pGH activity in hypox rats. On the basis of these previous observations, an attempt was made in this study to determine whether or not the peptide pGH(54-95) could be used as a vaccine to elicit antibodies functionally similar to PS-7.6 mAb, thus potentiating the efficacy of endogenous GH in swine. Young pigs (15-20 kg) were immunized with pGH(54-95) that had been conjugated with ovalbumin (OVA) and boosted twice at 4-week intervals. Control animals were similarly immunized with OVA. The weight gains and feed consumption of these animals were closely monitored throughout the trials. A number of carcass parameters were also examined when these animals reached 110-120 kg, at which time they were killed. Results indicated that immunization with peptide significantly accelerated the daily weight gain during the growing phase of growth. However, this effect disappeared during the finishing phase of growth. The failure to prolong the initial growth effect by the peptide immunization apparently correlated with the kinetics of antibody production, because antibodies immunoreactive to the peptide and pGH were detected in these animals after immunization but gradually diminished. This idea was supported by the fact that antibodies obtained from pigs 5 and 9 weeks after the initial immunization potentiated the activity of pGH in hypox rats, whereas antibodies harvested at week 16 did not. Furthermore, carcass evaluation was performed at time of killing and showed that the leaf fat and loin eye muscle were also significantly improved by peptide immunization. Taken together, the present findings suggest that pGH(54-95) peptide can be employed as a potential growth-promoting vaccine to improve the performance of swine.
一种名为PS-7.6的小鼠单克隆抗体（mAb），先前已被证明可增强猪生长激素（pGH）促进垂体切除（hypox）大鼠生长的活性。表位作图研究表明，PS-7.6识别的区域位于pGH的氨基酸序列54 - 95内。合成了与该序列对应的肽段，发现其能诱导产生可增强hypox大鼠体内pGH活性的猪抗体。基于这些先前的观察结果，本研究试图确定肽pGH(54 - 95)是否可用作疫苗来引发功能类似于PS-7.6 mAb的抗体，从而增强猪体内内源性生长激素（GH）的功效。用与卵清蛋白（OVA）偶联的pGH(54 - 95)对15 - 20千克的幼猪进行免疫，并每隔4周加强免疫两次。对照动物用OVA进行类似免疫。在整个试验过程中密切监测这些动物的体重增加和采食量。当这些动物达到110 - 120千克体重时将其处死，此时还检查了一些胴体参数。结果表明，用肽免疫可在生长的生长阶段显著加速日增重。然而，这种效应在生长的育肥阶段消失。肽免疫未能延长最初的生长效应显然与抗体产生的动力学有关，因为在免疫后这些动物体内检测到了对该肽和pGH有免疫反应的抗体，但这些抗体逐渐减少。这一观点得到以下事实的支持：在初次免疫后5周和9周从猪体内获得的抗体增强了hypox大鼠体内pGH的活性，而在第16周采集的抗体则没有。此外，在处死时进行了胴体评估，结果表明肽免疫还显著改善了板油和腰眼肌。综上所述，目前的研究结果表明，pGH(54 - 95)肽可作为一种潜在的促生长疫苗来提高猪的生产性能。
