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Background Cholera toxin and its two subunits (CTA,CTB) have been intensively investigated as mucosal adjuvants for protein based vaccine. In this study we evaluated the adjuvanticity of CTA and CTB in modality of either mixing their encoding plasmids with DNA vaccine or fusing their encoding genes to immunogen encoding gene. Methods DNA and recombinant vaccinia vaccines expressing HIV-1 AE strain tat, rev, intergrase(C-half), vif, nef fusion gene (designated as TRIVN) have been constructed. For the construction of fusion gene of CTA/CTB to TRIVN, overlapping PCR was employed to link CTA/CTB and TRIVN gene, the fused genes(TRIVN-CTA and TRIVN-CTB)were cloned into eukaryotic expression plasmid vector(pSV1.0). Six groups of female BALB/c mice were immunized with mock control, pSV-TRIVN, pSV-TRIVN-CTA, pSVTRIVN-CTB, pSV-TRIVN mixed with CTA or with CTB respectively in a DNA priming-recombinant vaccinia boosting regimen. Two weeks after the final injection, mice splenocytes were collected and IFN-g ELISPOT assay were used as readout for specific T cell response. Statistical analysis was performed by using Prism5.0 software. Results Our data showed that all constructed plasmids are capable of efficiently expressing their inserted genes. All groups immunized with vaccines raised significant more T-cell response than mock control. T-cell responses elicited by pSV-TRIVN-CTB(1548±330SFCs/106splenocytes) and pSV-TRIVN-CTA (1642±514SFCs/106splenocytes) were significantly higher than that by pSV1.0-TRIVN (520±150SFCs/106splenocytes), pSV1.0-TRIVN mixed with CTA (692±220SFCs/106splenocytes) and pSV1.0TRIVN mixed with CTB (734±240SFCs/106splenocytes). Though TRIVN-CTA and TRIVN-CTB fusion vaccines mounted comparable level of total IFN-g+ T-cell responses, only TRIVN-CTB elicits significantly T-cell responses against Tat, which is a subdominant component in the fusion immunogen. No significant differences were observed among groups inoculated with TRIVN alone or adjuvanted by CTA/CTB subunit proteins. Conclusion CTA and CTB could serve as potent adjuvants for DNA vaccine in immunogen-CTA/CTB fusion modality. Compared with CTA, CTB may enhance T-cell responses against subdominant epitopes in the immunogen and broaden the T-cell immune responses.

BackgroundPreserving the C7 spinous process during cervical laminoplasty has been reported to prevent axial symptom. Some patients underwent laminectomy and fixation developed the symptom. The objective of this article was to investigate whether axial symptom can be reduced by preserving the C7 spinous process during cervical laminectomy and fixation with lateral mass screw.MethodsBetween 2005 and 2008, data of 53 patients who underwent laminectomy and lateral mass-screw fixation for multilevel cervical myelopathy were reviewed. Analysis consisted of the incidence of axial symptom, Japan Orthopaedic Association (JOA) scores, recovery rate, cervical lordotic angle, and atrophy rate of cervical posterior muscle. Axial symptom severity was quantified by a visual analog scale (VAS). Twenty-five patients were decompressed from C3 to C7 (group A) and 28 from C3 to C6 with dome-shape removal of the C7 superior lamina (group B).ResultsAnalysis of final follow-up data showed improvement in clinical outcome for both groups. No difference in recovery rate, cervical lordotic angle and atrophy rate was observed between groups. Postoperative axial-neck pain was significantly rarer in group B than in group A. Axial symptom severity was correlated with cervical posterior muscle atrophy rate; correlation coefficient was 0.665.ConclusionThe C7 spinous process might play an important role in preventing axial symptom, but there is a need for randomized, control studies with long-term follow-up to clarify the results.