Sastry Mallika, Zhang Baoshan, Chen Man, Joyce M Gordon, Kong Wing-Pui, Chuang Gwo-Yu, Ko Kiyoon, Kumar Azad, Silacci Chiara, Thom Michelle, Salazar Andres M, Corti Davide, Lanzavecchia Antonio, Taylor Geraldine, Mascola John R, Graham Barney S, Kwong Peter D
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Institute for Research in Biomedicine, Bellinzona, Switzerland.
PLoS One. 2017 Oct 26;12(10):e0186854. doi: 10.1371/journal.pone.0186854. eCollection 2017.
Appropriate adjuvant selection may be essential to optimize the potency and to tailor the immune response of subunit vaccines. To induce protective responses against respiratory syncytial virus (RSV)-a highly prevalent childhood pathogen without a licensed vaccine-we previously engineered a pre-fusion-stabilized trimeric RSV F (pre-F) "DS-Cav1" immunogen, which induced high titer RSV-neutralizing antibodies, in mice and non-human primates, when formulated with adjuvants Poly (I:C) and Poly (IC:LC), respectively. To assess the impact of different adjuvants, here we formulated RSV F DS-Cav1 with multiple adjuvants and assessed immune responses. Very high RSV-neutralizing antibody responses (19,006 EC50) were observed in naïve mice immunized with 2 doses of DS-Cav1 adjuvanted with Sigma adjuvant system (SAS), an oil-in-water adjuvant, plus Carbopol; high responses (3658-7108) were observed with DS-Cav1 adjuvanted with Alum, SAS alone, Adjuplex, Poly (I:C) and Poly (IC:LC); and moderate responses (1251-2129) were observed with DS-Cav1 adjuvanted with the TLR4 agonist MPLA, Alum plus MPLA or AddaVax. In contrast, DS-Cav1 without adjuvant induced low-level responses (6). A balanced IgG1 and IgG2a (Th2/Th1) immune response was elicited in most of the high to very high response groups (all but Alum and Adjuplex). We also tested the immune response induced by DS-Cav1 in elderly mice with pre-existing DS-Cav1 immunity; we observed that DS-Cav1 adjuvanted with SAS plus Carbopol boosted the response 2-3-fold, whereas DS-Cav1 adjuvanted with alum boosted the response 5-fold. Finally, we tested whether a mixture of ISA 71 VG and Carbopol would enhanced the antibody response in DS-Cav1 immunized calves. While pre-F-stabilized bovine RSV F induced very high titers in mice when adjuvanted with SAS plus Carbopol, the addition of Carbopol to ISA 71 VG did not enhance immune responses in calves. The vaccine response to pre-F-stabilized RSV F is augmented by adjuvant, but the degree of adjuvant-induced enhancement appears to be both context-dependent and species-specific.
选择合适的佐剂对于优化亚单位疫苗的效力和调整其免疫反应可能至关重要。为了诱导针对呼吸道合胞病毒（RSV）的保护性反应（RSV是一种高度流行的儿童病原体，目前尚无获批疫苗），我们之前构建了一种预融合稳定的三聚体RSV F（pre-F）“DS-Cav1”免疫原，当分别与佐剂聚肌胞苷酸（Poly (I:C)）和聚肌胞苷酸-卵磷脂（Poly (IC:LC)）联合使用时，该免疫原在小鼠和非人类灵长类动物中诱导出了高滴度的RSV中和抗体。为了评估不同佐剂的影响，我们在此用多种佐剂配制了RSV F DS-Cav1并评估了免疫反应。在用Sigma佐剂系统（SAS，一种水包油佐剂）加卡波姆佐剂的两剂DS-Cav1免疫初始小鼠中，观察到了非常高的RSV中和抗体反应（19,006 EC50）；在用明矾、单独的SAS、Adjuplex、聚肌胞苷酸（Poly (I:C)）和聚肌胞苷酸-卵磷脂（Poly (IC:LC)）佐剂的DS-Cav1免疫小鼠中，观察到了高反应（3658 - 7108）；在用Toll样受体4（TLR4）激动剂单磷酰脂质A（MPLA）、明矾加MPLA或AddaVax佐剂的DS-Cav1免疫小鼠中，观察到了中等反应（1251 - 2129）。相比之下，无佐剂的DS-Cav1诱导出的反应水平较低（6）。在大多数高至非常高反应组（除明矾和Adjuplex外的所有组）中引发了平衡的IgG1和IgG2a（Th2/Th1）免疫反应。我们还测试了在已有DS-Cav1免疫的老年小鼠中DS-Cav1诱导的免疫反应；我们观察到，用SAS加卡波姆佐剂的DS-Cav反应增强了2 - 3倍，而用明矾佐剂的DS-Cav1反应增强了5倍。最后，我们测试了ISA 71 VG和卡波姆的混合物是否会增强DS-Cav1免疫犊牛的抗体反应能力。虽然预融合稳定的牛RSV F在用SAS加卡波姆佐剂时在小鼠中诱导出了非常高的滴度，但在ISA 71 VG中添加卡波姆并未增强犊牛的免疫反应。佐剂可增强对预融合稳定的RSV F的疫苗反应，但佐剂诱导的增强程度似乎既取决于背景，也具有物种特异性。
