title: Biological and biochemical characterization of HIV-1 Gag/dgp41 virus-like particles expressed in Nicotiana benthamiana.
abstract: The transmembrane HIV-1 envelope protein gp41 has been shown to play critical roles in the viral mucosal transmission and infection of CD4⁺ cells. Gag is a structural protein configuring the enveloped viral particles and has been suggested to constitute a target of the cellular immunity that may control viral load. We hypothesized that HIV enveloped virus-like particles (VLPs) consisting of Gag and a deconstructed form of gp41 comprising the membrane proximal external, transmembrane and cytoplasmic domains (dgp41) could be expressed in plants. To this end, plant-optimized HIV-1 genes were constructed and expressed in Nicotiana benthamiana by stable transformation, or transiently using a Tobamovirus-based expression system or a combination of both. Our results of biophysical, biochemical and electron microscopy characterization demonstrates that plant cells could support not only the formation of enveloped HIV-1 Gag VLPs, but also the accumulation of VLPs that incorporated dgp41. These findings provide further impetus for the journey towards a broadly efficacious and inexpensive subunit vaccine against HIV-1.
authors.affiliation: School of Life Sciences and The Biodesign Institute, Arizona State University, Tempe, AZ, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Kessans
authors.forename: Mark D
authors.initials: MD
authors.lastname: Linhart
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matoba
authors.forename: Tsafrir
authors.initials: T
authors.lastname: Mor
mesh_terms: D018506:Gene Expression Regulation, Plant; D005813:Genes, Synthetic; D015700:HIV Envelope Protein gp41 / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D018515:Plant Leaves / Q000648:ultrastructure / Q000821:virology; D030821:Plants, Genetically Modified; D014026:Nicotiana / Q000235:genetics / Q000821:virology*; D014771:Virion / Q000648:ultrastructure; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000378:metabolism*
chemical_list: D015700:HIV Envelope Protein gp41; D054301:gag Gene Products, Human Immunodeficiency Virus; C514787:gp41 protein, Human immunodeficiency virus 1
keywords: Gag; HIV-1; enveloped virus-like particles; gp41; transgenic plants; transient expression