Open AccessAn antibody derivative expressed from viral vectors passively immunizes pigs against transmissible gastroenteritis virus infection when supplied orally in crude plant extracts
Author(s) -
Monger Wendy,
Alamillo Josefa M.,
Sola Isabel,
Perrin Yolande,
Bestagno Marco,
Burrone Oscar R.,
Sabella Patricia,
PlanaDuran Joan,
Enjuanes Luis,
Garcia Juan A.,
Lomonossoff George P.
Publication year - 2006
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/j.1467-7652.2006.00206.x
Subject(s) - potato virus x , biology , virology , antibody , virus , endoplasmic reticulum , western blot , kdel , cowpea mosaic virus , neutralization , signal peptide , microbiology and biotechnology , plant virus , recombinant dna , biochemistry , gene , immunology , golgi apparatus
Summary To investigate the potential of antibody derivatives to provide passive protection against enteric infections when supplied orally in crude plant extracts, we have expressed a small immune protein (SIP) in plants using two different plant virus vectors based on potato virus X (PVX) and cowpea mosaic virus (CPMV). The ɛSIP molecule consisted of a single‐chain antibody (scFv) specific for the porcine coronavirus transmissible gastroenteritis virus (TGEV) linked to the ɛ‐CH4 domain from human immunoglobulin E (IgE). In some constructs, the sequence encoding the ɛSIP molecule was flanked by the leader peptide from the original murine antibody at its N‐terminus and an endoplasmic reticulum retention signal (HDEL) at its C‐terminus to allow the expressed protein to be directed to, and retained within, the endoplasmic reticulum. Western blot analysis of samples from Nicotiana clevelandii or cowpea tissue infected with constructs revealed the presence of SIP molecules which retained their ability to dimerize. The analysis of crude plant extracts revealed that the plant‐expressed ɛSIP molecules could bind to and neutralize TGEV in tissue culture, the levels of binding and neutralization reflecting the level of expression. Oral administration of crude extracts from SIP‐expressing plant tissue to 2‐day‐old piglets demonstrated that the extracts which showed the highest levels of in vitro neutralization could also provide in vivo protection against challenge with TGEV.