Interaction between a 54-Kilodalton Mammalian Cell Surface Protein and Cowpea Mosaic Virus

Abstract

Cowpea mosaic virus (CPMV), a plant virus that is a member of the picornavirus superfamily, is increasingly being used for nanotechnology applications, including material science, vascular imaging, vaccine development, and targeted drug delivery. For these applications, it is critical to understand the in vivo interactions of CPMV within the mammalian system. Although the bioavailability of CPMV in the mouse has been demonstrated, the specific interactions between CPMV and mammalian cells need to be characterized further. Here we demonstrate that although the host range for replication of CPMV is confined to plants, mammalian cells nevertheless bind and internalize CPMV in significant amounts. This binding is mediated by a conserved 54-kDa protein found on the plasma membranes of both human and murine cell lines. Studies using a deficient cell line, deglycosidases, and glycosylation inhibitors showed that the CPMV binding protein (CPMV-BP) is not glycosylated. A possible 47-kDa isoform of the CPMV-BP was also detected in the organelle and nuclear subcellular fraction prepared from murine fibroblasts. Further characterization of CPMV-BP is important to understand how CPMV is trafficked through the mammalian system and may shed light on how picornaviruses may have evolved between plant and animal hosts.In the past several years, aside from understanding the natural life cycles of viruses as obligate intracellular pathogens, the power of viruses as tools for material applications has begun to be harnessed. There are several reasons why viruses are an excellent choice in this regard. First, rigid viral capsids provide natural molecular scaffolds that allow precise attachments for building nanostructures, with control over orientation and spacing that is not attainable using other materials, such as dendrimers or liposomes (14,26,29,31,46). Second, virus capsids use highly repeated structural motifs allowing for the polyvalent display of peptides (11), polysaccharides (22, 48), nucleic acids (54), or other synthetic structures (43). Selfassembly of virus capsids also ensures a lack of morphological polydispersity in the capsid size and shape, which is difficult to accomplish using synthetic materials (35,36). Third, viral genomes are generally easy to manipulate, allowing the generation of mutants that can allow specific tailoring of the particle surface (12,13,60,61). Fourth, procedures for inexpensive, efficient amplification of many such structures, e.g., plant viruses, virus-like particles, and bacteriophages, are already well defined (24,25,41,49,67).Plant viruses are especially attractive for development in material science, nanotechnology, and vaccine applications because of their ease of production and purification. In particular, cowpea mosaic virus (CPMV) has been studied increasingly as a material for these purposes. CPMV is the type member of the genus Comovirus, which is part of the Picornaviridae superfamily spanning the plant and animal kingdoms and including Poliovirus and Rhinovirus. CPMV has a singl...

Bio-distribution, toxicity and pathology of cowpea mosaic virus nanoparticles in vivo

“…Phages and CPMV have evolved to bind and replicate in bacteria and plants respectively, therefore were anticipated to have different circulation half lives in mammalian systems. However, unlike phages, CPMV particles were found to bind to a 54 kDa protein expressed on a variety of mammalian cells including endothelial cells [25]. The rapid removal of CPMV from circulation may be related to this uptake of CPMV in endothelial cells [29].…”

The promotion of osteoblastic differentiation of rat bone marrow stromal cells by a polyvalent plant mosaic virus

“…In the past two decades, taking advantages of distinctive chemical and biological properties of plant viruses, new materials with unique structural features have been developed for a wide range of applications, including electronics, drug delivery, imaging, gene therapy, and immunotherapy [35][36][37][38][39][40][41][42][43][44][45][46][47]. Recent studies have reported that cowpea mosaic virus (CPMV) can interact with the mammalian cells due to the presence of two highly specific CPMV-binding proteins present in certain mammalian cells [48]. Furthermore, it was found that the rigid, densely arranged, and ordered repetitive protein display of coat proteins of viral capsids results in the mature B cells recognition and induces the IgM response [49].…”

Zeta potential: a surface electrical characteristic to probe the interaction of nanoparticles with normal and cancer human breast epithelial cells

“…The agglomeration of iron oxide nanoparticles after incubated with cells that we observed in TEM images may also be caused by smaller surface charge after protein adsorption and the repulsive forces by negatively charged cell surface. The uptake mechanism of CPMV nanoparticle by human cells is little known, but a recent study of CPMV have identified a mediated endocytosis of CPMV via a 54 kD protein found on the plasma membrane of both human and muring cell lines (Koudelka et al 2007). Figure 6 reveals the changes of Zeta potential values with theoretical fittings for MCF10A normal cells and MCF7 cancer cells after incubated with iron oxide and CPMV nanopaticles.…”

“…Cowpea mosaic virus (CPMV) is one of the smallest plant viruses, which is an icosahedron with a spherical average diameter of 28.4 nm that built from 60 copies of two asymmetric protein units assembled around a single-stranded bipartite RNA genome (Lewis et al 2006;Blum et al 2004). Its highly organized nanoblock structure, chemically addressable sites on the protein shell (the capsid) surface, and pH and thermally stability over a wide range of conditions make CPMV an excellent choice in biomedical applications including vaccines, vascular imaging, and targeted drug delivery (Lewis et al 2006;Koudelka et al 2007;Lomonossoff et al 1999). …”