ABSTRACT
Adjuvants have been used as critical components of vaccine.They were used to stabilize the antigens and potentiate the immune responses.Dose sparing is also of interests in recent years to be applied in potential pandemic situations or to lower the costs of vaccines.With the emerging nanotechnology in many aspects including the use in biomedical applications,the application of nanomaterials as vaccine adjuvants also attracted a lot of attentions in recent years.With favorable biological properties,such as well-defined and well-formed nanoparticles,biocompatibility,biodegradability and ability to induce humoral immunity and cellular immunity simultaneously,calcium phosphate nanoparticles (CaP) have the potentials to be developed as an immune potentiator to be used as vaccine adjuvants.Here,we reviewed the basic properties of CaP and their applications as vaccine adjuvants with antigens of different modalities such as inactivated virus,protein and naked DNAs.The mechanism of the adjuvanting effects is briefly described.Further the development of CaP as vaccine adjuvants with some designed surface modification could lead to next generation vaccine adjuvants with improved immune potentiating properties and safety profiles.
ABSTRACT
Aim To investigate the effect of intrathecal injection of fluorocitrate(Fc)on mechanical and thermal hyperalgesia induced by complete Freund's adjuvant(CFA)injection in rats.Methods The mechanical withdrawal threshold(MWT)and thermal withdrawal latency(TWL)were measured before and after CFA or Fc treatment.The changes of glial fibrillary acidic protein(GFAP)and OX-42(a microglial marker)expression in the spinal cord dorsal horn were evaluated by immunohistochemistry analysis.Results Rats with CFA-induced arthritis showed mechanical allodynia and thermal hyperalgesia,which was correlated with the increased GFAP and OX-42 expression in the spinal cord dorsal horn.Intrathecal injection of Fc markedly suppressed CFA-induced thermal hyperalgesia and mechanical allodynia.Fc significantly attenuated the activation of GFAP and OX-42 in the spinal cord dorsal horn.Conclusions The glia activation in spinal cord is closely related to the progress of CFA-induced peripheral hyperalgesia.Fc may exert antihyperalgesic effect by inhibiting the activation of astrocyte and microglia.
ABSTRACT
To reconstruct the heat-labile enterotoxin subunit B (LTB) gene of Escherichia coil in order to increase the outputs of the prokaryotic expression on recombinant LTB (rLTB), and to determine its immune adjuvant activity on mucosa,the nucleotide sequence of the whole length of LTB gene was synthesized according to the preferred codons of E. coli, and the prokaryotic expression plasmid pET32a-rLTB and its expression system in E. coli BL21DE3 were reconstructed. The recombinant plasmid was extracted and the inserted sequence of rLTB gene was determined. Meanwhile, the expression quantity of the reconstructed rLTB was identified by SDS-PAGE and BioRad agarose image analyzing system, and compared with that of the un-reconstructed rLTB. The abilities of the reconstructed rLTB and the un-reconstructed rLTB to bind with bovine GM1 were determined by means of GM1-ELISA assay. By using the recombinant urease subunit B as antigen, the effects of the reconstructed and the un-reconstructed rLTB on the improvement of immune protection of BALB/c mice infected with Helicobacter pylori strain SS1 and the induction of S-IgAs in infected mice were assayed. The experimental results showed that the expression quantity of the reconstructed rLTB approached upto 35.4% of the total bacterial proteins after induction with 1 mmol/L IPTG for pET32a-rLTB-E. coliBL21DE3 and to be 12.6 times higher than that of the un-reconstructed rLTB (2.8 %). In addition, both the abilities of the recombinant reconstructed LTB and the un-reconstructed rLTB to bind with bovine GM1 could be demonstrated by GM1-ELISA. The immune protection rate of the recombinant urease subunit B in the infected mice was 66.7%; and it could reach up to 91.7% with a significantincrease of the specific S-IgA level, when it was immunized with the reconstructed or the un-reconstructed rLTB. It is concluded that the reconstructed LTB gene in the present study shows a remarkable increased outputs of expression of this gene with a strong immune adjuvant activity on mucosa.
ABSTRACT
Recently we have shown that a bacterial flagellin, Vibrio vulnifiucs FlaB (Vv-FlaB), has a strong adjuvant activity to induce protective immune response. In order to investigate the adjuvanticity of Vv-FlaB, we prepared highly purified recombinant protein by using an intein fusion protein purification system. However, in the process of the purification, we unexpectedly encountered a contamination with a 70 kDa protein. We proved the 70 kDa protein as the heat shock protein 70 (HSP70) by Western blotting. Unfortunately, it was reported that the HSP70 has a strong adjuvanticity. In this study we investigated the role of contaminating HSP70 on the Vv-FlaB-mediated adjuvanticity. We separated Vv-FlaB and HSP70 by using a high performance protein purification chromatography and compared adjuvant activities of Vv-FlaB, HSP70 and Vv-FlaB/HSP70 mixture. Using an intranasal immunization mouse model, we observed that co-administration of the flagellin with tetanus toxoid (TT) induced significantly enhanced TT-specific antibody (Ig) responses. However contaminating doses of HSP70 did not affect the adjuvanticity of Vv-FlaB and furthermore HSP70 alone did not enhance TT-specific Ig response and protective immunity against lethal challenge with tetanus toxin. These results show that the HSP70 contaminating Vv-FlaB preparations did not affect the adjuvanticity of Vv-FlaB.
Subject(s)
Animals , Mice , Blotting, Western , Chromatography , Flagellin , Heat-Shock Proteins , Hot Temperature , HSP70 Heat-Shock Proteins , Immunization , Inteins , Staphylococcal Protein A , Tetanus Toxin , Tetanus Toxoid , Vibrio vulnificus , VibrioABSTRACT
Objective: To clone porcine IL-4 cDNA and observe its adjuvanticity of vaccine against T. solium cysticerco-sis. Methods:The cDNA of porcine IL-4 was amplified by RT-PCR, which had 5' AUG initiatory codon with optimized trans-lational initiation. After sequencing,the cDNA was intergrated into expression vector pcDNA and transient expression was performed. Then newborn pigs were immunized with IL-4 expression vector and protective antigen DNA vaccine against T. solium cysticercosis. Results:The obtained sequence of porcine IL-4 cDNA was the same as reported. IL-4 and protective antigen could effectively promote the humoral response. Conclusion:An efficient expression plasmid containing porcine IL-4 cDNA is constructed. Its adjuvanticity of DNA vaccine against T. solium cysticercosis is preliminarily conformed.