Gas Vesicle Nanoparticles for Antigen Display

Abstract

Microorganisms like the halophilic archaeon Halobacterium sp. NRC-1 produce gas-filled buoyant organelles, which are easily purified as protein nanoparticles (called gas vesicles or GVNPs). GVNPs are non-toxic, exceptionally stable, bioengineerable, and self-adjuvanting. A large gene cluster encoding more than a dozen proteins has been implicated in their biogenesis. One protein, GvpC, found on the exterior surface of the nanoparticles, can accommodate insertions near the C-terminal region and results in GVNPs displaying the inserted sequences on the surface of the nanoparticles. Here, we review the current state of knowledge on GVNP structure and biogenesis as well as available studies on immunogenicity of pathogenic viral, bacterial, and eukaryotic proteins and peptides displayed on the nanoparticles. Recent improvements in genetic tools for bioengineering of GVNPs are discussed, along with future opportunities and challenges for development of vaccines and other applications.

Bioengineering Novel Floating Nanoparticles for Protein and Drug Delivery

“…The GvpC fusion system represents a novel method for displaying proteins as a two-dimensional array on the external surface of the nanoparticles in a form which allows display and delivery to the mammalian immune and vascular systems[1, 5, 9-13, 15, 16]. As a result of the biocompatibility and the extreme stability of the nanoparticles, the potential of GVNPs is likely to be very significant.…”

“…Halophilic archaea (haloarchaea) such as Halobacterium sp. NRC-1 produce lemon-shaped GVNPs of about 300 nm length and 200 nm width[1]. …”

Microbial gas vesicles as nanotechnology tools: exploiting intracellular organelles for translational utility in biotechnology, medicine and the environment

“…Purified gas vesicles engineered to also display an antigen of interest, known as gas vesicle nanoparticles (GVNPs), can offer advantages over other vaccine types, including increased stability, immunogenicity and enhanced uptake across cell membranes [36][37][38]. Use of GVNPs can also avoid some of the downsides of live-attenuated vaccines, including a lower risk of infection, and they have the therapeutic potential to be given to immunocompromised individuals [33,37].…”

“…Gas vesicles have been purified from various organisms to determine their structure and protein composition [28][29][30][31][32] and there is a growing interest in the use of gas vesicles for biotechnological, medical and ecological applications. For example, gas vesicles are being investigated as antigen delivery vehicles, where promising results have already been observed in a range of systems [33]. Gas vesicles are under investigation as contrast agents for use in magnetic resonance imaging (MRI) and they have been proposed as a target for disrupting cyanobacterial blooms by exploiting ultrasonic collapse of the vesicles [34,35].…”

Little red floaters: gas vesicles in an enterobacterium

“…Adopting these approaches will permit future analysis of the effects of environmental stresses and other factors on turgor pressure of microbial cultures. Together, these applications for gas vesicles add to the already expanding list of their uses in biotechnology and medicine (DasSarma and DasSarma, 2015;Pfeifer, 2015).…”