Expression and Characterization of Yeast Derived Chikungunya Virus Like Particles (CHIK-VLPs) and Its Evaluation as a Potential Vaccine Candidate

Abstract

Chikungunya virus (CHIKV) has emerged as a global health concern due to its recent spread in both old and new world. So far, no CHIKV specific drug or vaccine is licensed for human use. In this study, we report production of Chikungunya virus like particles (CHIK-VLPs) using novel yeast expression system (Pichia pastoris) and its evaluation as vaccine candidate. The gene encoding structural polyprotein of CHIKV from a recent epidemic strain was cloned into yeast expression system. The multicopy integrants were processed for expression of CHIK-VLPs. The VLPs were purified and confirmed through electron microscopic analysis for their morphological identity with CHIKV. The in vitro and in vivo evaluation of CHIK-VLPs as vaccine candidate was determined in Balb/c mice. Induction of both humoral and cellular immune response was observed with different doses of CHIK-VLPs. The humoral immune response was studied through different techniques like enzyme linked immunosorbent assay, IgG Isotyping and plaque reduction neutralization test. CHIK-VLPs were found to elicit high titer of antibodies that are able to recognize native CHIKV. Higher level of IgG2a and IgG1 subtypes was identified suggestive of balanced Th1/Th2 response. Both in vitro and in vivo neutralization activity of CHIK-VLPs antibodies was observed even with low concentration, which shows its high specificity and neutralizing activity against two different CHIKV strains. Neonatal mice receiving anti-CHIK-VLPs antibodies were protected from CHIKV challenge. Induction of cellular immune response was confirmed through higher level of TNF-α, IL-10 and substantial level of IL-2, IL-4 and IFN-γ indicating a balanced response. This is the first report, where CHIK-VLPs has been expressed by Pichia pastoris and evaluated for neutralizing activity against CHIKV. These promising results indicate the utility of CHIK-VLPs as a promising vaccine candidate against emerging CHIKV.

Detection of chikungunya virus‐specific IgM on laser‐cut paper‐based device using pseudo‐particles as capture antigen

“…Moreover, they do not require chemical inactivation, as with viral lysate, reducing the risk of alterations of antigenic epitopes. Synthetic viruses are well characterized and have already been considered to be a powerful template to develop next‐generation vaccines . However, there are few references in the literature regarding the use of these antigens as diagnostic tools …”

“…Synthetic viruses are well characterized and have already been considered to be a powerful template to develop next-generation vaccines. 47,[62][63][64] However, there are few references in the literature regarding the use of these antigens as diagnostic tools. 65,66 Interestingly, using MAC-ELISA, a very strong detection signal for It has previously been shown that the PAD sensitivity is generally lower than that for ELISA.…”

Production of virus-like particles for vaccines

“…Due to the ability of yeast to perform post-translational modifications, it represents a step forward in VLP production. Recently, Chikungunya VLPs were produced using P. pastoris and promising results were obtained in terms of murine immunisation [15]. Indeed, several yeast-produced VLPs have already reached approval by regulatory agencies, such as papillomavirus VLP [16].…”

Yeast as an expression system for producing virus-like particles: what factors do we need to consider?

“…Moreover, contamination with endotoxins is a critical consideration in manufacturing injectable vaccines because it can cause severe side effects such as septic shock and tissue damage (Magalhaes et al 2007). Studies have suggested that endotoxins can be removed effectively by treatment with Triton X-114 (Liu et al 1997;Schadlich et al 2009). Recently, moreover, it has been possible to enhance the solubility of target proteins and to use endotoxin-free E. coli cell lines (Sorensen and Mortensen 2005;Mamat et al 2015).…”