Intranasal co-delivery of IL-6 gene enhances the immunogenicity of anti-caries DNA vaccine

Abstract

Aim: To investigate the effects of co-delivering IL-6 expressing plasmid pCI-IL-6 on the immunogenicity of the anti-caries DNA vaccine pCIA-P, which encodes the surface protein antigen PAc of Streptococcus mutans. Methods: Plasmid pCI-IL-6 was constructed by inserting the murine IL-6 gene into the pCI vector. Expression of IL-6 in vitro was assessed using Western blot analysis. BALB/c mice were intranasally co-immunized with pCIA-P plus pCI-IL-6 on d 0 and 14. Anti-PAc IgG and secretory IgA (sIgA) were assessed by ELISA. Splenocytes from the mice were re-stimulated with the PAc protein, and IFN-γ and IL-4 production was measured using ELISA. Splenocyte proliferation was analyzed with flow cytometry. Rats were similarly immunized, and dental caries scores were determined using the Keyes method. Results: Marked expression of IL-6 was found in COS-7 cells transfected with pCI-IL-6. In the pCI-IL-6 co-immunized mice, the specific IgG antibodies in serum and sIgA antibodies in saliva were significantly higher than those in the control mice at weeks 4 and 8. Moreover, the secretion of IFN-γ from splenocytes in response to re-stimulation with PAc protein was significantly higher in the pCI-IL-6 co-immunized mice than that in the control mice, whereas the secretion of IL-4 had no significant difference. The proliferation of splenocytes from the pCI-IL-6 co-immunized mice was significantly higher than that from the mice immunized with pCIA-P and pCI vector. In the rat caries model, the pCI-IL-6 co-immunization rats displayed lower caries scores than the control rats. Conclusion: Intranasal co-delivery of IL-6 gene significantly enhances the immunogenicity of the anti-caries DNA vaccine.

RETRACTED ARTICLE: Self-assembling anticaries mucosal vaccine containing ferritin cage nanostructure and glucan-binding region ofS. mutansglucosyltransferase effectively prevents caries formation in rodents

“…Collection of saliva and blood and analysis of splenocyte proliferation were performed according to published methods. 27 The levels of IFN-g and IL-4 in the supernatants of splenocytes after treatment of 24 h with 20 mg/mL GLU were measured using cytokine ELISA kits (R&D Systems, Oxon, UK). Serum IgG isotypes were determined according to methods described in a previous study, 2 and the levels of specific antibodies against GLU were determined using an ELISA with Maxisorp microtiter plates (Greiner Bio-one, Frickenhausen, Germany) coated with GLU as described previously.…”

Modulation of Biofilm Exopolysaccharides by the Streptococcus mutans vicX Gene

“…The SmuvicX biofilms were dynamically shifted toward “desertification,” as they were devoid of enriched exopolysaccharide–microcolony complexes. We found that knockout of the vicX gene led to a lower cariogenic incidence in the rats, according to a modified Keyes' counting method (Keyes, 1958 ; Koo et al, 1999 ; Su et al, 2014 ). The SmuvicX strain is associated with a marked reduction in the development of carious lesions which emphasized vicX may have relevance characterization for biofilm formation in vivo (Table 2 ).…”

“…After washing with phosphate-buffered saline twice, two pieces were selected. The lower jaws were dissected and immersed in10% buffered formalin phosphate for 72 h. The rat teeth were observed under a stereomicroscope to determine the caries levels according to modified Keyes score (Keyes, 1958 ; Koo et al, 1999 ; Su et al, 2014 ).…”

Nanotechnology in dentistry: prevention, diagnosis, and therapy

“…82 Many candidate anticaries DNA vaccines have been or are undergoing usage tests in animals or human beings. Examples of these vaccines include pcDNA3-Pac, 83 pCIA-P, 84 pGJGLU/ VAX, 85 and pGLUA-P. 86 Most of the anticaries vaccines work by preventing bacterial accumulation either by blocking the surface protein antigen PAc or inactivation of glucosyltransferases enzyme. 87 Both surface protein antigen PAc and glucosyltransferases are the virulent factors responsible for the adhesion of S. mutans to tooth surfaces.…”