Immunogenicity of porcine transmissible gastroenteritis virus spike protein expressed in plants

Medical molecular farming: production of antibodies, biopharmaceuticals and edible vaccines in plants

“…Plant-expressed antigens have been shown to able to induce mucosal and serum immune responses when administered parenterally or orally to experimental animals and, in some test cases, they have offered protection against a subsequent pathogen challenge or challenge model 14,16,[19][20][21][22][23][24] . A few of these vaccine candidates have been successfully tested in clinical trials or, where appropriate, in commercial or native animal trials [25][26][27][28][29][30] . Thus, edible vaccines delivered in plant tissues or processed plant products show great potential for efficacy in target organisms.…”

“…Thus, achieving a high level of expression is crucial. The expression of vaccine components in plants has been increased by using a range of leader and polyadenylation signals 31 and by optimizing codon usage for plants 22,29,30 . Expression could also be raised through crosses of transformed lines to various genetic backgrounds, an approach that has been successfully applied to boost protein production in corn.…”

“…It is also important that any vaccine component should be present in its native form in the transgenic plant tissue. This has been assessed in several cases by examining the size of the synthesized protein, its ability to form higher-order complexes that mirror microbial or viral structures and, where relevant, by showing an enzymatic or receptor-binding activity 14,[16][17][18]22,24,29 .…”

“…Favored locations for the expression of selected subunit vaccine components are the cell surface and the endoplasmic reticulum and Golgi body 14,18,29,31,32 . As with antibodies, transient expression systems (in which candidate vaccine sequences are incorporated into plant viral surface proteins) have also been investigated extensively and high levels of expression have been achieved.…”

Transgenic Plant Vaccine: A Breakthrough in Immunopharmacotherapeutics

“…Since then, several proteins of different origin have been expressed in plants. These include Escherichia coli heat-labile enterotoxin antigen [11], Enkephalins [12], Human serum albumin [13], Glucocerebrosidase and granulocyte macrophage colony stimulating factor [14], Norwalk virus surface protein [15], VP1 antigen from foot and mouth disease virus [16,17], cholera toxin B subunit [18], Rabies antigen [19], the S protein of transmissible gastroenteritis coronavirus [20,21], Respiratory synctial virus G and F proteins [8,22], the VP6 protein of rotavirus [23], the measles [24] and Rinderpest [25], virus hemagglutinin proteins and an epitope from the major surface antigen of Plasmodium falciparum [26].…”