Antibodies from transgenic plants

Floss, D.M., Sack, M., Stadhnann, J., Rademacher, T, Scheller, J., Stoger, E., Fischer, R., and Conrad, U. (2008). Biochemical and functional characterization of anti-HIV antibody-ELP fusion proteins from transgenic plants. Plant Biotechnol. J. Epub ahead of print. 

Tobacco suspension cells initiated from transgenic plants ScFv antibody fragment CaMV 35 S Apoplast targeting (spor-amin secretion signal) 1 mg extracellular, 5 mg intracellular 42... 

Table 8.1 lists examples of vaccines produced in transgenic plants. Table 8.2 shows several possibilities for antibody production in transgenic plants and Table 8.3 demonstrates the range of biopharmaceuticals under development from transgenic plants. 

Fig. 8.1 Western blot analysis of transgenic lines showing the expression of an assembled monoclonal antibody in transgenic chloroplasts. Lane 1 Extract from a chloroplast transgenic line, Lane 2 Extract from an untransformed plant. Lane 3 Positive control (human IgA). The gel was run under non-reducing conditions. The antibody was detected with an AP-conjugated goat anti-human kappa antibody.

Fig. 8.7 CTB-GM1-ganglioside binding ELISA assay. Plates, coated first with GMrganglioside and bovine serum albumin (BSA), respectively, were irrigated with total soluble plant protein from chloroplast transgenic lines (3 and 7) and 300 ng of purified bacterial CTB. The absorbance of the GM1-ganglioside-CTB-antibody complex in each case was measured at 405 nm. Total soluble protein from untransformed plants was used as the negative control.

Fig. 8.10 Titers of antibodies at day 50 induced by plant-derived CTB-2L21 recombinant protein. Balb/c mice were intraperitoneally immunized with leaf extract from CTB-2L21 transgenic plants. Animals were boosted at days 21 and 35. Each mouse received 20 pg of CTB-2L21 recombinant protein. Individual samples of mouse serum were titrated against 2L21 synthetic peptide,VP2 protein and a control peptide (amino acids 122-135 of hepatitis B virus surface antigen). Titers were expressed as the highest serum dilution to yield twice the absorbance mean of preimmune sera. M1-M6 mice 1 to 6 2L21 epitope from the VP2 protein of the canine parvovirus CTB cholera toxin B VP2 protein of the canine parvovirus that includes the 2L21 epitope.

Fig. 15.4 Structure of glycans N-linked to IgG molecules expressed in hybridomas and transgenic plants. Glycans N-linked to plant-derived antibodies are structurally different from their mammalian counterparts. In contrast with antibodies produced in alfalfa, antibodies produced in tobacco plants present a very high glycan heterogeneity.

In 1990, the first plant-made vaccines were performed via expression of Streptococcus mutans surface protein A in transgenic tobacco, followed by oral immunization of mice with the same plant material (Fischer and Emans, 2000). This transgenic plant material was later shown to successfully induce an antibody response through a demonstration that serum from immunized mice could react with intact S. mutans. Plants were also developed that expressed Escherichia coli enterotoxin B subunit (LT-B) and that exhibited successful inducement of both mucosal and serum antibody responses (Tacket, 2005). These initial experiments led to a cornucopia of studies involving generations of plant-made vaccines and therapeutic proteins and their applications in medicine. 

Drake, P.M., Chargelegue, D.M., Vine, N.D., van Dolleweerd, C.J., Obregon, P, and Ma, J.K. (2003). Rhizosecretion of a monoclonal antibody protein complex from transgenic tobacco roots. Plant Mol. Biol. 52 233-241. 

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