Cytotoxic T cell responses are enhanced by antigen design involving the presentation of MUC1 peptide on cholera toxin B subunit

Abstract

Induction of cytotoxic T lymphocytes (CTL) is critical to cancer vaccine based immunotherapy. Efforts to elicit CTLs against tumor MUC1 with peptide based vaccine have not been successful in clinical application. We have design a MUC1 vaccine by replacing B cell epitope of CTB with MUC1 VNTR peptide. Immunization with hybrid CTB-MUC1 plus aluminum hydroxide and CpG adujuvant (CTB-MUC1-Alum-CpG) induce MUC1-specific CTLs in mice. Moreover, this vaccination can prevent tumor growth and reduce tumor burden in MUC1+B16 mice model. Meanwhile, CTB-MUC1-Alum-CpG vaccination can promote Th1 cells and CD8+ T cells inflate to tumor tissue. Our approach might be applicable to other cancer vaccine design.

The Immunogenicity and Anti-Tumor Efficacy of a Rationally Designed EGFR Vaccine

“…As a clinically approved adjuvant for human vaccine, alum is rarely used in formulation of human cancer vaccine because it facilitates Th2 type of immune response. Interestingly, work from Lu et al show that in presence of CpG, alum formulated cancer vaccine is effective in eliciting Th1 type of immune responses [19]. Consistent with this report, we showed that CpG and Alum formulated DEGFR m could elicit Th1 type of immune response and anti-tumor effect in mouse tumor models.…”

“…The plates were kept on an orbital shaker for 5 min. The absorbance at 570 nm was measured by a microplate reader (PE EnSpire TM ) [19, 20]. …”

“…Intracellular IFN-γ was examined as described [19]. Briefly, splenocytes were incubated with brefeldin A (10mM, MultiSciences, China) for 6 hours to block IFN-γ secretion.…”

“…Real time PCR was performed using the SYBR Green kit (Fermentas, USA) following the manufacturer’s instructions. Data was analyzed using the 2 –∆∆CT method [19, 21]. The primer sequences are listed in Table 1.…”

“…Moreover, DTT-based antigen is immunogenic when formulated with Alum, a widely used adjuvant in human vaccination. We and others also show that CpG enhances antitumor immunity when formulated with cancer vaccine [18, 19]. Based on these observations, we designed a vaccine formulation comprising a recombinant immunogen against EGFR, named as DEGFR m vaccine, which was composed of DEGFR m CpG and Alum adjuvants.…”