Generation of a tumor vaccine candidate based on conjugation of a MUC1 peptide to polyionic papillomavirus virus-like particles

Abstract

Virus-like particles (VLPs) are promising vaccine technology due to their safety and ability to elicit strong immune responses. Chimeric VLPs can extend this technology to low immunogenicity foreign antigens. However, insertion of foreign epitopes into the sequence of self-assembling proteins can have unpredictable effects on the assembly process. We aimed to generate chimeric bovine papillomavirus (BPV) VLPs displaying a repetitive array of polyanionic docking sites on their surface. These VLPs can serve as platform for covalent coupling of polycationic fusion proteins. We generated baculoviruses expressing chimeric BPV L1 protein with insertion of a polyglutamic-cysteine residue in the BC, DE, HI loops and the H4 helix. Expression in insect cells yielded assembled VLPs only from insertion in HI loop. Insertion in DE loop and H4 helix resulted in partially formed VLPs and capsomeres, respectively. The polyanionic sites on the surface of VLPs and capsomeres were decorated with a polycationic MUC1 peptide containing a polyarginine-cysteine residue fused to twenty amino acids of the MUC1 tandem repeat through electrostatic interactions and redox-induced disulfide bond formation. MUC1- fully assembled VLPs induced robust activation of bone marrow-derived dendritic cells, which could then present MUC1 antigen to MUC1-specific T cell hybridomas and primary naïve MUC1-specific T cells obtained from a MUC1-specific TCR transgenic mice. Immunization of human MUC1 transgenic mice, where MUC1 is a self-antigen, with the VLP vaccine induced MUC1-specific CTL, delayed the growth of MUC1 transplanted tumors and elicited complete tumor rejection in some animals.

Development and characterization of Rift Valley fever virus-like particles

“…Furthermore, VLPs are able to undergo efficient antigen processing and presentation through either major histocompatibility complex class I or class II molecules, thereby inducing strong humoral and cellular immune responses (Bachmann et al, 1996;Pejawar-Gaddy et al, 2010;Win et al, 2011;Liu et al, 2013). Moreover, VLPs can directly induce dendritic cell maturation, and thus positively regulate costimulatory molecule expression and cytokine secretion, further activating CD8 + T lymphocytes (Bosio et al, 2004;Yang et al, 2004).…”

Bovine papillomavirus: opening new trends for comparative pathology

“…Research on BPV has led to most of the recent breakthroughs on the biology and pathology of animal papillomavirus, with major implications for human health. Using such spontaneous models, researchers have recently made significant discoveries on the interaction of papillomavirus with chemical carcinogens and immunosuppressants [4], on the role of BPV oncoproteins in cell transformation and immune evasion, on the infection of some unusual cell types and the possibility of haematogenous transplacental BPV transmission [5], as well as on new prophylactic and therapeutic vaccines [6][7][8].…”

Central nervous system-specific consequences of simian immunodeficiency virus Gag escape from major histocompatibility complex class I-mediated control

“…The virus-like particle (VLP)-based vaccine was composed of bovine papillomavirus L1 capsid protein that was genetically engineered to contain 8 glutamic acids and a cysteine in a surface exposed loop of the protein with Gag KP9 covalently linked to the particle (Pejawar-Gaddy et al , 2010). The negatively charged glutamic acids served as docking sites for protein/peptide antigens with an NH2 tag of 8 positively charged arginines and flanking cysteines.…”