Production of Rotavirus-Like Particles in Tomato (Lycopersicon esculentumL.) Fruit by Expression of Capsid Proteins VP2 and VP6 and Immunological Studies

Abstract

A number of different antigens have been successfully expressed in transgenic plants, and some are currently being evaluated as orally delivered vaccines. Here we report the successful expression of rotavirus capsid proteins VP2 and VP6 in fruits of transgenic tomato plants. By western blot analysis, using specific antibodies, we determined that the VP2 and VP6 produced in plants have molecular weights similar to those found in native rotavirus. The plant-synthesized VP6 protein retained the capacity to form trimers. We were able to recover rotavirus virus-like particles from tomato fruit (i.e., tomatoes) by centrifugation on a sucrose cushion and to visualize them by electron microscopy. This result indicated that VP2/VP6 can self-assemble into virus-like particles (VLPs) in plant cells, even though only a small proportion of VP2/VP6 assembled into VLPs. To investigate immunogenicity, adult mice were immunized intraperitoneally (i.p.) three times with a protein extract from a transgenic tomatoes in adjuvant. We found that the transgenic tomato extract induced detectable levels of anti-rotavirus antibodies in serum; however, we did not determine the contribution of either the free rotavirus proteins or the VLPs to the induction of the antibody response. These results suggest the potential of plant-based rotavirus VLPs for the development of a vaccine against rotavirus infection.

Cross-reactivity of anti-Eimeria tenella antibody fragments on merozoites and sporozoites of different chicken Eimeria species

“…Such antibodies produced in plants used for animal feeding could offer a simple and inexpensive biopharmaceutical means for coccidiosis control. Plant-based antibodies (plantibodies) are supposed as alternative options to control several animal diseases, for example foot and mouth disease (Santos et al 2005), rinderpest (Khandelwal et al 2003a, b), rotavirus infection (Saldana et al 2006) and infectious bronchitis virus (Zhou et al 2003). Plant-based recombinant chicken sIgA was expressed in tobacco leaves and induced immune protection against coccidiosis (Wieland et al 2006).…”

Immunogenicity and virus-like particle formation of rotavirus capsid proteins produced in transgenic plants

“…Many researchers have successfully produced and purified RV VLPs in insect cells; however, the efficiency of assembly of RV VLPs in insect cells is very low, with only about 15% of the total virus capsid proteins produced in the insect cells participating in the formation of RV VLPs [40,41]. The self-assembly efficiency of 2/6-RV VLPs produced in transgenic plants was even lower [38]. In this study, we came to the same conclusion by comparing the stoichiometric mass of proteins in the supernatant with that in the pellet purified through a sucrose cushion.…”

“…At present the VLPs of several viruses have been produced in plants successfully, for example, human papillomavirus-like particles and Norwalk VLPs in transgenic tobacco and potato plants, respectively [32][33][34]; cottontail rabbit papillomavirus-like particles in tobacco plants [35]; hepatitis B virus (HBV) VLPs in tobacco, soybean and potato plants [36,37]; rotavirus 2/6 VLPs in tomato plants [38]; recombinant HIV-1/HBV VLPs in tobacco and Arabidopsis plants [39]. In this study, we co-expressed three capsid proteins, VP2, VP6 and VP7 of group A RV in tobacco plants.…”

Developments in Plant-Based Vaccines Against Diseases of Concern in Developing Countries

“…Another approach was reported by Saldaña et al (2006). In this case the successful expression of rotavirus capsid proteins VP2 and VP6 in fruits of transgenic tomato plants was demonstrated.…”

“…To investigate immunogenicity, adult mice were immunized intraperitoneally three times with a protein extract from transgenic tomatoes in adjuvant. Transgenic tomato extract induced detectable levels of anti-rotavirus antibodies in serum; however, the contribution of either the free rotavirus proteins or the VLPs to the induction of the antibody response was not determined [68].…”