We hypothesize that human exposures to environmental stresses (biological, chemical, physical and psychological) result in alterations to the neuro-endocrine-immune axis. These changes provoke shifts in molecular components of the blood that reflect changes in biomarker levels. Septic patients and rheumatoid arthritis patients will be used as prototype stressed individuals to identify and quantify the presence of serum proteins that have increased, decreased, or which display epitope-modified expression. These molecular features will form the basis of specific biomarker signatures that are characteristic of stressed human individuals. Preliminary experiments document that biological, chemical, and psychological stress alters plasma protein expression levels, which in part, are due to inflammation and/or oxidative processes. Since we suggest the different forms of stressors modulate the interactive pathways between the endocrine, immune, and nervous systems, we anticipate that immune, endocrine, and nervous system factors will be predictors of stress and that the profiles of these factors will provide prognosis for the degree of stress and the severity of the exposure. Individual biomarkers, which are predicted to relate to regulatory pathways associated with inflammation:anti-inflammation, oxidants:anti-oxidants, and innate immune processes, will then be quantified in humanized mice after exposure to three prototype stressors: cadmium, cold-restraint, and listerial infection. Our plan is to delineate and quantify the normal basal and responsive plasma concentrations of relevant biomarkers and to validate their analysis with a new biosensor employing grating- coupled surface plasmon resonance imaging (GCSPRI). GCSPRI is a microarray platform that will enable the multiplexed detection of these biomarker signatures with an automated diagnostic system in near real time. In addition to stressor-induced changes in plasma constituents, we will evaluate changes to blood leukocyte antigens; lymphocytes are especially sensitive to inflammatory products and oxidants. Blood products are obtained with minimal invasiveness, and they represent the best composite of the systemic response to a stressor. The GCSPRI technology will be parallel tested against the Luminex technology. The biomarkers to be evaluated include blood clotting factors, cytokines, stress proteins, neuropeptides, antioxidant enzymes, and normal plasma proteins with thiol-related modifications. Finally, we will evaluate the consequences of different stress response capabilities on the character of the biomarker signatures that have been identified in this work. At the conclusion of this work we will have identified specific biomarker signatures that are both diagnostic of specific signatures, and which will be invaluable in both the diagnosis of stress, and the characterization of therapeutic management of stressed individuals.
