Messenger RNA vaccine based on recombinant MS2 virus‐like particles against prostate cancer

Abstract

Prostate cancer (PCa) is the most diagnosed cancer in the western male population with high mortality. Recently, alternative approaches based on immunotherapy including mRNA vaccines for PCa have shown therapeutic promise. However, for mRNA vaccine, several disadvantages such as the instability of mRNA, the high cost of gold particles, the limited production scale for mRNA-transfected dendritic cells in vitro, limit their development. Herein, recombinant bacteriophage MS2 virus-like particles (VLPs), which based on the interaction of a 19-nucleotide RNA aptamer and the coat protein of bacteriophage MS2, successfully addressed these questions, in which target mRNA was packaged by MS2 capsid. MS2 VLP-based mRNA vaccines were easily prepared by recombinant protein technology, nontoxic and RNase-resistant. We show the packaged mRNA was translated into protein as early as 12 hr after phagocytosed by macrophages. Moreover, MS2 VLP-based mRNA vaccines induced strong humoral and cellular immune responses, especially antigen-specific cytotoxic T-lymphocyte (CTL) and balanced Th1/Th2 responses without upregulation of CD4 1 regulatory T cells, and protected C57BL/6 mice against PCa completely. As a therapeutic vaccine, MS2 VLP-based mRNA vaccines delayed tumor growth. Our results provide proof of concept on the efficacy and safety of MS2 VLP-based mRNA vaccine, which provides a new delivery approach for mRNA vaccine and implies important clinical value for the prevention and therapy of PCa.

RETRACTED ARTICLE: Cell-specific delivery of messenger RNA and microRNA by recombinant MS2 virus-like particles carrying cell-penetrating peptide

“…Previously, the largest size of RNA packaged in MS2 VLPs without peptide insertion was 3034 bases; the RNA was packaged by utilizing three C-variant pac sites in a prokaryotic expression system (Song et al 2011), while in a eukaryotic expression system, the largest size was 1581 bases, where the RNA was packaged by adding two C-variant pac sites (Li et al 2014). So far, the largest size of RNA packaged using one wild-type pac site in MS2 VLPs with peptide was 813 bases (Peabody et al 2008), and that of RNA packaged using one C-variant pac site was 720 bases.…”

“…Bacteriophage MS2 virus-like particles (VLPs) may be a promising tool that can meet these requirements, because these particles can be expressed in Escherichia coli (Sun et al 2013) and Saccharomyces cerevisiae (Li et al 2014). Additionally, the MS2 coat protein can self-assemble into VLPs in the absence of viral RNA, and these VLPs can be used as a vector for peptides (Mastico et al 1993).…”

“…In previous studies, the MS2 capsid without inserted peptide can package the RNA (mRNA (Li et al 2014), microRNA (Pan et al 2012), antisense oligonucleotides (Wu et al 2005)) by interacting with a specific 19-nuclotide stem-loop (pac site) generally located at the 3′ terminus of the target RNA. Therefore, this system is advantageous in protecting RNA from the degradation by RNase.…”

Design and Production of mRNA-based Gene Vectors for Therapeutic Reprogramming of Cell Fate

“…The majority of gene vector types leave a permanent genetic trace in target cells because of the irreversible chromosomal integration of their genetic material. Integration can be mediated by specialized enzymatic machinery, e.g., in retroviral [55], lentiviral vectors [56] and eukaryotic transposons [57]. After gene delivery with some other vector types, such as plasmid vectors [58] or minicircle vectors [59,60], chromosomal integration occurs through spontaneous target-cell-mediated recombination.…”

Vaccines against human diarrheal pathogens

“…57 The O-antigen modification in Shigella flexneri is transmitted by serovar-specific temperate bacteriophages. 58 Antigen variation in pathogens may call the generation of multivalent vaccines, and recent examples are the pneumococcal polyvalent polysaccharide vaccines representing 23, or pneumococcal conjugate vaccines (PCV) representing 10 or 13 of the 83 capsule serotypes, respectively. 59 Production of polyvalent vaccines is cost intensive, since various antigens have to be produced and combined in amounts sufficiently high to trigger immunity against the important serotypes of the pathogen.…”