Enhanced Immune Responses with Serum Proteomic Analysis of Hu Sheep to Foot-and-Mouth Disease Vaccine Emulsified in a Vegetable Oil Adjuvant

Abstract

Our previous study demonstrated that a vegetable oil consisting of soybean oil, vitamin E, and ginseng saponins (SO-VE-GS) had an adjuvant effect on a foot-and-mouth disease (FMD) vaccine in a mouse model. The present study was to compare the adjuvant effects of SO-VE-GS and the conventional ISA 206 on an FMD vaccine in Hu sheep. Animals were intramuscularly (i.m.) immunized twice at a 3-week interval with 1 mL of an FMD vaccine adjuvanted with SO-VE-GS (n = 10) or ISA 206 (n = 9). Animals without immunization served as control (n = 10). Blood was sampled prior to vaccination and at 2, 4, 6, and 8 weeks post the booster immunization to detect FMD virus (FMDV)-specific IgG. Blood collected at 8 weeks after the booster was used for the analyses of IgG1 and IgG2, serum neutralizing (SN) antibody, IL-4 and IFN-γ production, and proteomic profiles. The results showed that IgG titers rose above the protection level (1:128) in SO-VE-GS and ISA 206 groups after 2 and 4 weeks post the booster immunization. At 6 weeks post the booster, the ISA 206 group had 1 animal with IgG titer less than 1:128 while all the animals in the SO-VE-GS group retained IgG titers of more than 1:128. At 8 weeks post the booster, 6 of 9 animals had IgG titers less than 1:128 with a protective rate of 33.3% in the ISA 206 group, while only 1 of 10 animals had IgG titer less than 1:128 with a protective rate of 90% in the SO-VE-GS group, with statistical significance. In addition, IgG1, IgG2, SN antibodies, IL-4, and IFN-γ in the SO-VE-GS group were significantly higher than those of the ISA 206 group. Different adjuvant effects of SO-VE-GS and ISA 206 may be explained by the different proteomic profiles in the two groups. There were 39 and 47 differentially expressed proteins (DEPs) identified in SO-VE-GS compared to the control or ISA 206 groups, respectively. In SO-VE-GS vs. control, 3 immune related gene ontology (GO) terms and 8 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were detected, while 2 immune related GO terms and 5 KEGG pathways were found in ISA 206 vs. control. GO and KEGG analyses indicated that ‘positive regulation of cytokine secretion’, ‘Th1/Th2 cell differentiation’, and ‘Toll-like receptor signaling pathways’, were obviously enriched in the SO-VE-GS group compared to the other groups. Coupled with protein–protein interaction (PPI) analysis, we found that B7TJ15 (MAPK14) was a key DEP for SO-VE-GS to activate the immune responses in Hu sheep. Therefore, SO-VE-GS might be a promising adjuvant for an FMD vaccine in Hu sheep.

Safety and Efficacy of the Bordetella bronchiseptica Vaccine Combined with a Vegetable Oil Adjuvant and Multi-Omics Analysis of Its Potential Role in the Protective Response of Rabbits

“…In our previous studies, E515 as an FMD vaccine adjuvant was shown to activate vigorous humoral and cellular responses [ 20 , 21 ]. Based on the good safety of the E515- Bb vaccine in rabbits, its immune effects were further demonstrated by evaluating antigen-specific humoral and cellular responses on days 7, 14, 21, and 28 post-boost immunization.…”

“…To gain insight into the signaling pathways involved in the response to the E515-adjuvanted Bb vaccine, KEGG enrichment analysis was conducted [ 21 ]. The pathways identified in the E515- Bb group by RNA-seq were mainly involved in DNA replication, protein processing and the cell cycle, and these pathways were all downregulated when compared to those in the other two groups ( Figure 5 ).…”

“…In our previous studies, RNA-seq-based transcriptomic and tandem mass tags (TMT) proteomic analyses were used to investigate the mechanisms underlying the adjuvant in mouse models and Hu sheep, respectively [ 20 , 21 ]. However, generally single omics technologies cannot always comprehensively reveal the potential molecular mechanisms.…”

“…The whole-inactivated bacterial was adjuvanted with E515 or Alum at a ratio of 1:2 ( v / v ) or 1:1 ( v / v ), and the prepared vaccines contained inactivated 1.2 × 10 10 CFU/mL Bb antigen. The E515-adjuvanted Bb vaccine was prepared as previously described [ 20 , 21 ] with some modifications, and each mL of the soybean oil contained both VE (100 µg) and GS (60 µg). Briefly, the mixture was emulsified at a shear rate of 16,000 rpm for 5 min (IKA T10 basic, ULTRA-TURRAX1, Staufen, Germany) to form an oil-in-water (O/W) emulsion.…”

Sunflower seed oil containing ginseng stem–leaf saponins (E515-D) is a safe adjuvant for Newcastle disease vaccine

“…Besides, compared with the mineral-originated oil, vegetable oil is renewable, edible, and safe. Although previous studies have demonstrated the adjuvant effect of some vegetable oil formulations in mice, swine, and sheep ( Zhang et al., 2014 , Zhang et al., 2018 ; Cui et al., 2020 ), the vegetable oil as an adjuvant in poultry vaccine is barely reported. Our preliminary studies found that a vegetable origin oil E515-D, which comprised sunflower seed oil and ginseng saponins from GSLS, could form a stable water-in-oil ( W/O ) emulsion ( Yuan et al., 2020 ).…”