Plant expression systems for production of hemagglutinin as a vaccine against influenza virus.

Abstract

Many examples of a successful application of plant-based expression systems for production of biologically active recombinant proteins exist in the literature. These systems can function as inexpensive platforms for the large scale production of recombinant pharmaceuticals or subunit vaccines. Hemagglutinin (HA) is a major surface antigen of the influenza virus, thus it is in the centre of interests of various subunit vaccine engineering programs. Large scale production of recombinant HA in traditional expression systems, such as mammalian or insect cells, besides other limitations, is expensive and time-consuming. These difficulties stimulate an ever-increasing interest in plant-based production of this recombinant protein. Over the last few years many successful cases of HA production in plants, using both transient and stable expression systems have been reported. Various forms of recombinant HA, including monomers, trimers, virus like particles (VLPs) or chimeric proteins containing its fusion with other polypeptides were obtained and shown to maintain a proper antigenicity. Immunizations of animals (mice, ferrets, rabbits or chickens) with some of these plant-derived hemagglutinin variants were performed, and their effectiveness in induction of immunological response and protection against lethal challenge with influenza virus demonstrated. Plant-produced recombinant subunit vaccines and plant-made VLPs were successfully tested in clinical trials (Phase I and II) that confirmed their tolerance and immunogenicity.

Plant‐produced candidate countermeasures against emerging and reemerging infections and bioterror agents

“…Many studies have been reported on the development of plant‐based influenza subunit vaccines (reviewed in Chichester et al ., ; D'Aoust et al ., ; López‐Macías, ; Redkiewicz et al ., ; Yusibov et al ., ). In regard to structure, three types of plant‐produced influenza subunit vaccine candidates have been produced: monomeric HA, trimeric HA and HA‐based enveloped VLPs.…”

Progress in the development of virus-like particle vaccines against respiratory viruses

“…In this clinical study, 18-49 years old subjects were intramuscularly administered H1-VLPs at 5-, 13-, and 28-μg H1 HA-VLPs. The clinical results were found to be safe and well tolerated at all dose levels and even 5-µg dose of VLPs induced greater than 1:40 HAI titers in 83% of the subjects in this lowvaccine dose group [43] (Table 4). Two randomized Phase II clinical trials in 18 to 49 and over 50 years old adults have shown that the 30-µg dose of quadrivalent plant-derived influenza VLP vaccine produced consistent humoral and cellular responses [129].…”

“…In brief, mammalian cells were co-transfected with three different cloned recombinant plasmids such as M1, HA, and NA, respectively, M1 from A/ Puerto Rico/8/1934 strain, NA from A/Thailand/1(KAN-1)/2004 and codon-optimized HA protein from clade 2 H5N1. Plant cells are being used for expression and production of recombinant HA influenza VLP vaccines, which are currently under clinical trials to evaluate the immunogenicity, safety, and efficacy [43] (Tables 1 and 2). Various forms of recombinant HA, including monomers, trimers, virus-like particles or chimeric proteins were obtained by plant-based technology.…”

“…VLPs obtained by harvesting plant cells, homogenizing, and purification. Plant-made VLPs showed morphological stable structures over time, eliciting both humoral and cellular responses in mice, ferrets, rabbits, or chickens [43][44][45] (Tables 1, 2 , 4). A plant-derived H1-VLP vaccine was reported to induce significantly higher levels of IgG antibodies, CD4 + , and CD8 + T cell responses compared to inactivated virus vaccine in aged mice [45].…”

“…However, the adverse events were mild-to-moderate and self-limited. Another phase I clinical trial has been completed with plant cell derived HA seasonal influenza VLP vaccine to evaluate the immunogenicity, safety, and efficacy [43]. In this clinical study, 18-49 years old subjects were intramuscularly administered H1-VLPs at 5-, 13-, and 28-μg H1 HA-VLPs.…”