Archaeosomes and Gas Vesicles as Tools for Vaccine Development

Abstract

Archaea are prokaryotic organisms that were classified as a new domain in 1990. Archaeal cellular components and metabolites have found various applications in the pharmaceutical industry. Some archaeal lipids can be used to produce archaeosomes, a new family of liposomes that exhibit high stability to temperatures, pH and oxidative conditions. Additionally, archaeosomes can be efficient antigen carriers and adjuvants promoting humoral and cellular immune responses. Some archaea produce gas vesicles, which are nanoparticles released by the archaea that increase the buoyancy of the cells and facilitate an upward flotation in water columns. Purified gas vesicles display a great potential for bioengineering, due to their high stability, immunostimulatory properties and uptake across cell membranes. Both archaeosomes and archaeal gas vesicles are attractive tools for the development of novel drug and vaccine carriers to control various diseases. In this review we discuss the current knowledge on production, preparation methods and potential applications of archaeosomes and gas vesicles as carriers for vaccines. We give an overview of the traditional structures of these carriers and their modifications. A comparative analysis of both vaccine delivery systems, including their advantages and limitations of their use, is provided. Gas vesicle- and archaeosome-based vaccines may be powerful next-generation tools for the prevention and treatment of a wide variety of infectious and non-infectious diseases.

Halophilic Archaea Halorhabdus Rudnickae and Natrinema Salaciae Activate Human Dendritic Cells and Orient T Helper Cell Responses

“…To our knowledge, this is the first report on the effect of halophilic archaea on the maturation of human DCs and the subsequent orientation of CD4 + T cells. However, archaeosomes, which are unique liposomes composed of specific lipid extracts from halophilic archaea, almost exclusively from Halobacterium salinarum, have been produced and assessed as vaccine vehicles against various pathogens [for a recent review see (31)]. These liposomes have been shown to induce both antibody and T cell responses to the passenger antigens, implying that halophile compounds can activate antigen-presenting cells and trigger adaptive immunity.…”

Enhancing the Effect of Nucleic Acid Vaccines in the Treatment of HPV-Related Cancers: An Overview of Delivery Systems

“…Archaea, a domain of single-celled living things morphologically similar to bacteria but genetically distinct, are also used as vaccine delivery systems, especially in the form of archaeosomes [191]. The archaeosome is a liposome-based nano-delivery system developed for gene delivery.…”

Archaeosomes: New Generation of Liposomes Based on Archaeal Lipids for Drug Delivery and Biomedical Applications

“…The lipid film is then resuspended in chloroform, methanol, and water mixture, and again evaporated under vacuum. The dried lipid film is then hydrated with an aqueous buffer to form archaeosomes . Usually, the drug or a biomolecule (e.g., protein) of interest can be either encapsulated (hydrophilic) or entrapped (hydrophobic) in the archaeosomes during their formulation or incubated with the archaeosomes after their formation .…”

“…The dried lipid film is then hydrated with an aqueous buffer to form archaeosomes. 2 Usually, the drug or a biomolecule (e.g., protein) of interest can be either encapsulated (hydrophilic) or entrapped (hydrophobic) in the archaeosomes during their formulation or incubated with the archaeosomes after their formation. 17 A variety of microscopic techniques such as cryo-transmission electron microscopy, scanning electron microscopy, fluorescence microscopy, and phase-contrast light microscopy are widely used to analyze the morphology of archaeosomes.…”

“…They represent the third domain of life on earth and are evolutionarily distinct from the other two domains, namely bacteria and Eukarya. Archaea are well-known for their ability to grow and thrive in extreme habitats ranging from hot springs and volcanoes to hypersaline environments such as salt lakes and oceans, highly acidic or alkaline conditions, and high pressure that are hostile to most other organisms on earth. , Such organisms, known as extremophiles have been found at depths of 6.7 km inside the earth’s crust, more than 10 km deep inside the ocean at pressures of up to 110 MPa, from extreme acidic (pH 0) to extreme basic conditions (pH 12.8), and from hydrothermal vents at 122 °C to frozen seawater at −20 °C . Based on their living habitats, they are classified into different groups such as thermophiles and hyperthermophiles (able to grow at high or very high temperatures, respectively), psychrophiles (adapted to grow best at low temperatures), acidophiles and alkaliphiles (survive at high acidic or basic pH values, respectively), barophiles (able to thrive under pressure), and halophiles (organisms that require NaCl for growth) .…”