Recombinant pharmaceutical protein production in plants: unraveling the therapeutic potential of molecular pharming.

There is an increasing demand for the generation
of recombinant pharmaceutical proteins for a wide array of
therapeutic applications. In comparison to bacterial, yeast
and animal cells, the production of recombinant proteins in
plants with economic and therapeutic importance has only
started recently. The most important prerequisite of any
expression systems is that it should be simple and inexpensive.
In this regard, plant-based expression has emerged
an as accepted alternative to conventional expression
platforms due to economic feasibility, rapid scalability,
higher stability of recombinant proteins, safety due to lack
of harmful substances (human, animal pathogens and
pyrogens) and capability of producing proteins with desired
secondary modifications. Heterologous expression using
plants has played a pivotal role in the development of a
myriad of recombinant proteins, including neutraceuticals
and monoclonal antibodies being utilized in various therapeutic
approaches. This paper presents an overview about
the current status, various strategies and advantages of
pharmaceutical protein production in plant expression
systems. We also present a summary of expression of
therapeutic monoclonal antibodies, vaccines, clinical trials
and the regulatory aspects of plant-based expression. Furthermore,
the challenges encountered in plant expression
such as costs associated with existing purification strategies
are discussed.