James N. Herron

Our research program includes three different areas of investigation: (1) structure-function correlates of antigen-antibody complex formation; (2) biosensors and clinical diagnostics assays; and (3) targeted drug-delivery systems. A brief description of each of these is given below:

Structure-Function Correlates of Antigen-Antibody Complex Formation

The goal of this project is to understand antigen-antibody interactions at the molecular level. Our approach is to cross-correlate 3-dimensional structures obtained by X-ray crystallography with information obtained by other biophysical techniques such as fluorescence spectroscopy and calorimetry. By increasing our understanding of antigen-antibody interactions at the molecular level, we hope to comprehend how structural elements translate into the affinity and specificity of antigen-combining sites. Such mechanistic models should also facilitate the engineering of antibodies and related proteins for applications in clinical diagnostics, medical imaging and targeted drug delivery.

Biosensors and Clinical Diagnostics Assays

The goal of this project is to develop a new generation of clinical diagnostics assays that can be used in critical care or point-of-care settings. Our approach is based on planar waveguide biosensors that can selectively excite the fluorescence of molecules located within 100 nanometers of the surface of the waveguide. By immobilizing either antibodies or oligonucleotide probes to the surface of the waveguide, we can perform either immunoassays or nucleic acid hybridization assays with picomolar sensitivity in 5 minutes or less. Such assays are expected to replace the current generation of in vitro diagnostics (IVD) assays that are presently performed offsite in clinical chemistry laboratories.

This technology should lead to a significant improvement in the detection and treatment of cardiovascular disease, cancer and sexually transmitted diseases. It may also help address national priorities in the containment of health care costs.

Targeted Drug-Delivery Systems

Drug-delivery systems are typically used to improve the efficacy and safety of drugs that are poorly absorbed or have a low therapeutic index. This approach has been fairly successful, resulting in drug products such as sustained-release formulations, transdermal patches, liposomes and other colloidal delivery systems. Recent advances in biotechnology have enabled a whole new generation of drug delivery systems in which the drug is targeted to a specific site using a recognition moiety such as an antibody. We are developing targeted delivery systems for autoimmune diseases such as type I diabetes, systemic lupus erythematosus (SLE) and multiple sclerosis (MS). In particular, we are developing antibodies that will specifically target the B and T lymphocytes that are implicated in these diseases. In addition, we are working on non-traditional vaccines for autoimmune disease and cancer.