Highly efficient expression, purification of recombinant LTB protein and its activity against mucosal immunoadjuvant by nasal immunization

Objective To develop an efficient expression, purification system of recombinant Escherichia coli heat labile enterotoxin B subunit (rLTB) and study its activity against mucosal immunoadjuvant by nasal immunization Methods A recombinant, pMMB68 LTB was generated by cloning the LTB cDNA fragment into an expression vector (pMMB68) and transformed it into the host strain marine vibrio VSP60 The relevant target protein was identified using SDS polyacrylamide gel electrophoresis (SDS PAGE) and Western blot Sephacryl S 100 gel filtration chromatography was carried out for purification of rLTB in engineering bacteria VSP60 BALB/c mice received hen egg lysozyme (HEL) alone or combined with rLTB by nasal administration After three times immunization, IgG and IgA antibody levels in serum or small intestine wash samples were determined using ELISA Results rLTB protein was highly expressed in VSP60 After gel filtration with Sephacryl S 100, the purity of rLTB reached 98 1%, the yield rate was about 52% After immunization, IgG and IgA antibody responses specific to HEL in system and mucosa of HEL+rLTB groups were significantly increased, compared with the HEL alone group ( P <0 001) Conclusions A set of protocols for large scale rLTB preparation has been established, which is simple, efficient and applicable The rLTB protein we prepared was proved to be a powerful mucocal adjuvant, which could greatly enhance systemic and mucosal immune responses to nasally co administered antigen

Sendai virus-based immunoadjuvant in hydrogel vaccine intensity-modulated dendritic cells activation for suppressing tumorigenesis

The conventional immunoadjuvants in vaccine have weak effect on stimulating antigen presentation and activating anti-tumor immunity.Unexpectedly,we discovered that non-pathogenic Sendai virus(SeV)could activate antigen-presenting cells(APCs)represented by dendritic cells(DCs).Here,we designed an injectable SeV-based hydrogel vaccine(SHV)to execute multi-channel recruitment and stimulation of DCs for boosting the specific immune response against tumors.After the release of the NIR-triggered antigens from tumor cells,dendritic cells around the vaccine efficiently transport the antigens to lymph nodes and present them to T lymphocytes,thereby inducing systemic anti-tumor immune memory.Our findings demonstrated that the SHV with excellent universality,convenience and flexibility has achieved better immune protection effects in inhibiting the occurrence of melanoma and breast cancer.In conclusion,the SHV system might serve as the next generation of personalized anti-tumor vaccines with enhanced features over standard vaccination regimens,and represented an alternative way to suppress tumorigenesis.

Laser Immunotherapy:Novel Modality to Treat Cancer through Specific Antitumor Immune Response

Treatment of metastatic cancer remains a great challenge and needs novel approaches.Combining a selective photothermal therapy with an active immunological stimulation,laser immunotherapy(LIT) was developed to induce systemic immune responses through local intervention.LIT consists of three major components: a near-infrared laser,a light-absorbing agent,and an immunological stimulant.Its effect relies on two major interactions: a selective photothermal interaction and an active immunological stimulation.The selective photothermal interaction can reduce the tumor burden and at the same time release the tumor antigens,which can induce specific antitumor immune response.The expression of heat shock protein and the application of immunoadjuvant further enhance the host immunity.It has been proved in pre-clinical studies that LIT could not only eradicate treated local tumors but also regress and eliminate untreated metastases at distant sites.Moreover,LIT is well tolerated and has shown to have many advantages for cancer treatment compared with other traditional modalities.