Fig. 2: Design of VLP-based vaccines.
From: Immunization with VLP-based vaccines induces high IgG antibody titers in dermal interstitial fluid
Three separate VLP-based vaccines are used in this study. a Each vaccine antigen consists of a small peptide synthesized with a four-amino acid linker sequence at the C-terminus (represented by the blue bar). The linker sequence is necessary to chemically conjugate the peptides to purified Qβ VLPs. L9 VLPs display an epitope from the Plasmodium falciparum circumsporozoite protein (NANPNVDPNANPNVD), TRIO VLPs display an epitope from the Anopheles gambiae salivary protein, TRIO (VDDLMAKFN), and sialokinin VLPs display a ten-amino acid peptide isolated from Aedes aegypti saliva (NTGDKFYGLM). Image of the Qβ VLP was generated by the authors using online tools available through the RCSB protein data bank. b SDS-PAGE analysis of sialokinin-conjugated VLPs. Unmodified Qβ bacteriophage coat protein has a molecular weight of 14 kDa (WT VLPs; lane 2). Conjugation efficiency is assessed via shifts in molecular weight, based on the number of peptides attached per coat protein (+1–3). Gel images are from the same gel. c Durability of IgG antibody response in mice immunized with sialokinin VLPs. Female BALB/c mice (n = 5) were immunized with 5 µg of sialokinin VLPs and boosted 3 weeks later. Blood samples were collected up to 1 year post immunization and IgG antibodies against sialokinin were measured by ELISA. The dashed grey line represents the average IgG titer against WT VLPs (negative control, no antigen) after the second immunization. Data from L9 and TRIO VLP conjugations have been published13,15,21.
