Kazzaz Jina, Singh Manmohan, Ugozzoli Mildred, Chesko James, Soenawan Elawati, O'Hagan Derek T
Chiron Vaccines Research, Chiron Corporation, Emeryville, CA 94608, USA.
J Control Release. 2006 Feb 21;110(3):566-73. doi: 10.1016/j.jconrel.2005.10.010. Epub 2005 Dec 19.
Monophosphoryl lipid A (MPL) and the synthetic LPS mimetic RC529, encapsulated in poly(lactide-co-glycolide) (PLG) microparticles, were evaluated as immune potentiators in the presence of either HIV-1 gp120 protein or antigen from Neisseria meningitidis serotype B (Men B). The immunogenicity of these formulations was evaluated in mice and compared to CpG containing oligonucleotide. This work was done as part of an ongoing effort to enhance the potency of vaccine candidates against HIV and Men B.
Microparticles were made by a solvent evaporation method. Blank microparticles as well as microparticles with encapsulated MPL or RC529 were made using the PLG polymer RG503 and the ionic surfactant Dioctylsulfosuccinate by the water-in-oil-in-water emulsion technique. Antigens from HIV-1 and Men B were adsorbed on the surface of these anionic microparticles and the final formulations characterized for protein loading, release, and integrity. The formulations were then tested in mice for their ability to elicit antibodies and bactericidal activity in comparison with CpG containing oligonucleotide.
We have found that adding soluble immune potentiators to Men B antigen formulated on PLG microparticles significantly enhanced the immune response to a level comparable to that obtained using CpG. In a separate study, we found that encapsulating MPL or RC529 in PLG microparticles further enhanced the response in comparison to soluble CpG, which is our control group. Similarly, adding soluble immune potentiators to gp120 antigen formulated on PLG microparticles resulted in a significant enhancement of the immune response. Moreover, delivering MPL or RC529 encapsulated in PLG microparticles with gp120 adsorbed on PLG microparticles, resulted in even further enhancement of serum titers over those obtained with soluble immune potentiators. These titers were comparable to or greater than those obtained with soluble CpG, the control group. This effect was observed for both antigens regardless of whether or not the immune potentiator and the antigen were used with the same or with separate particles. In conclusion, the advantages of encapsulating MPL and RC529 lie not only in the enhanced immune response they elicit, but also in the convenience of handling these relatively insoluble compounds, and flexibility in vaccine design. The fact that MPL and RC529 are readily soluble in methylene chloride used for the manufacturing of PLG microparticles makes it easy to avoid solubility issues. Moreover, formulating antigen and immune potentiator with the same particle offers an attractive approach to vaccine delivery.
评估包裹于聚（丙交酯-乙交酯）（PLG）微粒中的单磷酰脂质A（MPL）和合成脂多糖模拟物RC529在存在HIV-1 gp120蛋白或B型脑膜炎奈瑟菌（Men B）抗原的情况下作为免疫增强剂的效果。在小鼠中评估这些制剂的免疫原性，并与含CpG的寡核苷酸进行比较。这项工作是正在进行的增强针对HIV和Men B候选疫苗效力努力的一部分。
通过溶剂蒸发法制备微粒。使用PLG聚合物RG503和离子表面活性剂二辛基磺基琥珀酸酯，通过水包油包水乳液技术制备空白微粒以及包裹有MPL或RC529的微粒。将HIV-1和Men B的抗原吸附在这些阴离子微粒表面，并对最终制剂进行蛋白质负载、释放和完整性表征。然后在小鼠中测试这些制剂与含CpG的寡核苷酸相比引发抗体和杀菌活性的能力。
我们发现，向PLG微粒上配制的Men B抗原中添加可溶性免疫增强剂可显著增强免疫反应，使其达到与使用CpG相当的水平。在另一项研究中，我们发现与作为对照组的可溶性CpG相比，将MPL或RC529包裹在PLG微粒中可进一步增强反应。同样，向PLG微粒上配制的gp120抗原中添加可溶性免疫增强剂可显著增强免疫反应。此外，将包裹有MPL或RC529的PLG微粒与吸附有gp120的PLG微粒一起给药，血清滴度比使用可溶性免疫增强剂时进一步提高。这些滴度与对照组可溶性CpG相当或更高。无论免疫增强剂和抗原是使用相同的微粒还是单独的微粒，两种抗原均观察到这种效果。总之，包裹MPL和RC529的优点不仅在于它们引发的免疫反应增强，还在于处理这些相对不溶性化合物的便利性以及疫苗设计的灵活性。MPL和RC529易于溶解于用于制造PLG微粒的二氯甲烷中，这使得避免溶解性问题变得容易。此外，将抗原和免疫增强剂用同一微粒配制为疫苗递送提供了一种有吸引力的方法。
