Immunomolecular biology

Science programme: Genomic technologies

Our researchers have a wide range of skills in immunology, molecular biology, natural product chemistry and biochemistry.We can control, through expression of antibody fragments, molecular processes within plants or plant cells. This allows us to answer fundamental questions related to the role of specific molecules. Antibodies are generated as part of an animal's natural defence when it is exposed to foreign substances. White blood cells produce a single antibody species, termed a monoclonal antibody (MAb). MAbs bind to a specific region on the foreign substance, enabling it to be eliminated. Immunologists have developed animal cell culture technologies to produce cell lines that secrete MAbs to compounds of interest and utilise the specificity of these antibodies to detect, measure and purify molecules present in complex biological mixtures.

We can produce antibodies to potential hazardous substances such as pesticides and antibiotics that enter our food and environment. These antibodies have also been used to develop rapid immunoassays for detecting and quantifying residues. The binding site on the antibody molecule represents only a small portion, known as the hypervariable region, of the antibody molecule. Molecular biology has allowed scientists to construct antibody fragments, single chain hyperervariable regions termed ScFvs, and express them in plants. We are experts in the production of monoclonal antibodies and antibody fragments. As well as preparing Mabs to proteins, we have developed skills to generate antibodies to small biological and synthetic molecules, and developed inducible systems to express them in plants.

Small biological molecules perform many functions in plants. For example, small molecules secreted by pathogens allow them to invade plant tissue, while others act as hormones co-ordinating developmental processes and pathogen/pest responses. The Immunomolecular Biology team has developed technologies to block the functions of small molecules by removing them through binding by the ScFvs. Antibodies can also be generated to the hypervariable regions and these anti-idiotypic antibodies can mimic the original small molecule. ScFvs are encoded by a single gene and so can be expressed more easily than small molecules, which are often products of multiple genes. By expressing antibody mimics, under the control of suitable inducible promoter systems in plants, we can study the role of bioactive molecules in plant processes.

Our services:

• A custom designed asceptic animal cell culture laboratory;
• Fully equipped facility for protein purification;
• Plant growth facilities;
• A fully equipped laboratory for the development of immunoassays including ELISA, Fluorescence and Chemiluminescence immunoassays, immunohistology, and plasmon resonance (Biacore) assays.

Successes and research highlights:

• Development of a controllable gene expression system for whole plants, allowing an introduced gene to be switched on or off using a simple copper ion cue;
• Development of a "designed" immunomolecular system for tagging or identifying elite or genetically improved plant cultivars and small organisms;
• Identification of a negative regulatory element implicated in turning genes off during plant development;
• Development of novel immunoassay technology for detection of organophosphate residues;
• Development of a monoclonal antibody-based immunoassay for measuring a fungal toxin implicated in significant losses in forest production;
• Synthesis of a single chain antigen-binding protein specific for a fungal phytotoxin and its expression in plants;
• Production of a generic monoclonal antibody against penicillin antibiotics;
• Production of a generic monoclonal antibody against heterocyclic and aromatic organophosphate pesticides;
• Production of an anti-idiotypic monoclonal antibody and recombinant antibody mimics of fungal toxins;
• Production of monoclonal antibodies recognising different structural features of a chlorosis-inducing virulence factor isolated from Pseudomonas syringii;
• Characterisation of the structure of novel antibiotic and chlorosis inducing small molecules from Pseudomonas species.