Enhanced and long term immunogenicity of a Her-2/neu multi-epitope vaccine conjugated to the carrier CRM197 in conjunction with the adjuvant Montanide

BMC Cancer

Research Article

Christoph Zielinski¹  Nicholas Ede²  Michael Kundi³  Joshua Tobias⁴  Joanna Jasinska⁴  Ursula Wiedermann⁴  Karin Baier⁴ 

[1] Division of Oncology, Department of Medicine I, Medical University of Vienna, General Hospital, Vienna, Austria;Imugene Ltd., Suite 1, 1233 High Street, Armadale, 3143, Melbourne, VIC, Australia;Institute of Environmental Health, Medical University of Vienna, 1090, Vienna, Austria;Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Kinderspitalgasse 15, 1090, Vienna, Austria;

关键词: Her-2/neu;    Hybrid peptide;    Adjuvant;    Mice;    Humoral and cellular response;    Th1-deriving response;   

DOI  :  10.1186/s12885-017-3098-7

 received in 2016-08-17, accepted in 2017-01-31,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundWe previously identified three short single peptides (P4, P6 and P7) representing different B-cell epitopes on the extracellular domain of Her-2/neu for a vaccine that was tested in a phase-I clinical trial. Here we describe the improvement of the multi peptide vaccine by fusing the single peptides to a hybrid peptide P467.MethodsAfter coupling to either virosomes or to diphtheria toxoid CRM197 (CRM), the hybrid peptide was tested in different concentrations in combination with either Montanide or Aluminium hydroxide (Alum) in preclinical studies.ResultsAlready low amount (10 μg) of P467 conjugated to CRM led to faster onset of high antibody levels compared to the P467-virosome. The formulation P467-CRM-Montanide induced higher serum IgG antibody titers, compared with P467-CRM-Alum, as examined by ELISA using recombinant Her-2/neu or Her-2/neu natively expressed on the tumor cell line SK-BR-3. Compared to P467-CRM-Alum, higher in vitro production of IL-2 and IFNγ in the Montanide-immunized mice was induced after re-stimulation of splenocytes with CRM but also with P467, indicating a clear Th1-biased response. In contrast to the single B cell peptides, the hybrid peptide led to T cell proliferation and cytokine production as CD4 T cell epitopes were generated in the fusion region of the single peptides P4 and P6 or P6 and P7. Additionally, a significantly higher proportion IFNγ-producing CD8+ T cells was found in the P467-CRM-Montanide immunized mice, probably by Montanide-driven bystander activation. Importantly, anti-P467 IgG antibodies exhibited anti-tumor properties and the combination of anti-P467 specific IgG with Herceptin® was found to inhibit the proliferation of Her-2/neu-overexpressing cell line SK-BR-3 in a significantly higher capacity than Herceptin® alone.ConclusionsFusion of the B cell peptides has led to additional generation of CD4 T cell epitopes, and this P467-multi epitope vaccine was found to induce polyclonal antibody responses with anti-proliferative capacity against Her-2/neu. The hybrid vaccine together with Montanide induced higher and long-lasting antibody levels, Th1-biased cellular responses being superior to vaccination with the single B cell peptides. This vaccine formulation is now planned to be evaluated in a phase Ib/II study in Her-2/neu overexpressing cancer patients.

【 授权许可】

CC BY   
© The Author(s). 2017