Adjuvant Effects of Recombinant Plasmids of Porcine IL-4 and IFN-γ to Cysticercosis cellulosae Vaccines in Mice and Pigs

To investigate the adjuvant potential of porcine IL-4 and IFN-γ in mice and pigs, the genes of porcine IL-4 and IFN-γ were cloned and the recombinant mammalian expression plasmids were constructed for in vivo expression of the cytokines. Adjuvant effects of recombinant expression plasmids of IL-4 and IFN-γ （pcDNA-IL-4, pcDNA-IFN-γ） co-administrated with Cysticercus cellulosae crude antigen or TSOL18 recombinant protein antigen have been carried out in mice and pigs, respectively. We have demonstrated that recombinant plasmids of the cytokines as an adjuvant could induce stronger immune response in mice and pigs. With the C. cellulosae parasite antigen, porcine pcDNA-IL-4 induced higher specific antibody of immunized mice than pcDNA-IFN-γ. But pcDNA-IFN-γ is significantly stronger than that of no adjuvant or empty plasmids with the antigen control group. For the TSOL18 recombinant protein antigen vaccine, pcDNA-IL-4 still had a stronger ability to enhance specific antibody in swine than pcDNA-IFN-γ （P 〈 0.01）, but the immune protective rate was lower in challenged pigs （only 68.7%）. Although pcDNA-IFN-γ showed lower specific antibody, the protection rate was very high （91%） than other group （P 〈 0.01）. This study indicated that the recombinant expression plasmids of porcine IL-4 and IFN-γ display stronger adjuvant effects to C. cellulosae vaccine, further research should be carried out for understanding of the interaction mechanism.

Expression of Porcine Interleukin-2 and Porcine Interleukin-6 and Their Adjuvant Effects on Gene Deleted Vaccine of Pseudorabies Virus(TK^-/gG^-/LacZ^+)

Porcine interleukin-2 and porcine interleukin-6 cDNA sequences were cloned into the expressing vectors pET-28a and pGEX-KG respectively. They were expressed in E. coli BL21(DE3)with high-level production. The gene deleted vaccine of pseudorabies virus Ea strain(TK-/gG-/LacZ+)was mixed with the two different purified recombinant proteins each, or both, with the doses of 2, 5 or 10 μg ml-1. Ten groups of pseudorabies negative antibody swines were immuned twice with tested vaccines with different doses, or control vaccine, respectively. The antibody liters of the test groups were detected by neutralization test, and the daily weight gains of swines were calculated and analyzed statistically. In the study, all the neutralizing antibody ti-ters in test groups were higher than the control group, and the recombinant proteins appeared a dose dependent adjuvant effect. The tested vaccines with 2 μg ml-1 pIL-2 and with 10 μg ml-1 pIL-2/pIL-6 got significant and extremely significant differences, compared with the vaccines without pILs. The difference of the daily weight gain indicated the potential positive influence of pIL-2 and pIL-6 on immune protection.

Effects of Methylated Soybean Oil Adjuvant on Fomesafen Efficacy to Weeds

Tank-mix adjuvant has the potential to improve the weed control efficacy of post-emergence herbicides. In order to study the synergistic effect of adjuvant, the effects of different rates of fomesafen alone or applied methylated soybean oil adjuvant（MSO） were sprayed on redroot pigweed, abutilon and black nightshade under greenhouse condition. The results showed that fomesafen had different performance on the three weeds, and MSO adjuvant could effectively increase the control. The nightshade control was lower than other two weeds with all the fomesafen doses from 131.25 to 506.25 ga.i. · hm-2 with or without adjuvant. The control of abutilon was between the black nightshade and the redroot pigweed, and had better control at 375 ga.i. · hm-2 with adjuvant or 506.25 ga.i. · hm-2 alone or with adjuvant respectively. The results indicated that mixing adjuvant with fomesafen improved the control on weeds, especially at the low rate. Black nightshade was more difficult to control. The redroot pigweed had the most susceptibility to fomesafen alone or with adjuvant.

Identification of an ideal adjuvant for receptor-binding domain-based subunit vaccines against Middle East respiratory syndrome coronavirus

Middle East respiratory syndrome （MERS）, an emerging infectious disease caused by MERS coronavirus （MERS-CoV）, has garnered worldwide attention as a consequence of its continuous spread and pandemic potential, making the development of effective vaccines a high priority. We previously demonstrated that residues 377-588 of MERS-CoV spike （S） protein receptor-binding domain （RBD） is a very promising MERS subunit vaccine candidate, capable of inducing potent neutralization antibody responses. In this study, we sought to identify an adjuvant that optimally enhanced the immunogenicity of S377-588 protein fused with Fc of human IgG （S377-588-Fc）. Specifically, we compared several commercially available adjuvants, including Freund＇s adjuvant, aluminum, Monophosphoryl lipid A, Montanide ISA51 and MF59 with regard to their capacity to enhance the immunogenicity of this subunit vaccine. In the absence of adjuvant, S377-588-Fc alone induced readily detectable neutralizing antibody and T-cell responses in immunized mice. However, incorporating an adjuvant improved its immunogenicity. Particularly, among the aforementioned adjuvants evaluated, MF59 is the most potent as judged by its superior ability to induce the highest titers of IgG, IgG1 and IgG2a subtypes, and neutralizing antibodies. The addition of MF59 significantly augmented the immunogenicity of S377-588-Fcto induce strong IgG and neutralizing antibody responses as well as protection against MERS-CoV infection in mice, suggesting that MF59 is an optimal adjuvant for MERS-CoV RBD-based subunit vaccines.