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A goal of the Institute is to expand and apply current knowledge of cross-reactivity. For those who have allergies, and for those who research and treat allergies, cross-reactivity has immediate and profound impact. Cross-reactivity may magnify the effects of an allergy, for instance. As oranges cross-react with mesquite pollen, someone allergic to mesquite might increase the intensity of the mesquite reaction if he or she were to drink orange juice during pollen season. In turn, a person may be allergic to coconut and mesquite pollen, and when treated for the mesquite allergy the negative response to coconut disappears.
As allergies fall under the wider umbrella of hypersensitivity, cross-reactivity may also hold a key to treating other disorders. Indeed, while allergies result from having an oversensitive immune system, one that is out of control because of its being out of balance, this high degree of sensitivity may produce even more serious health problems. Representative of the importance of cross-reactions to conditions other than routine allergies is, for example, the relationship between strep bacteria and cardiac tissue. An immune response directed initially against the invading bacterium causing strep throat can eventually lead to heart damage in the form of rheumatic fever. Interrupting the cross-reactive process could therefore prevent such damage.
Just as the periodic chart displays the elemental building blocks of the physical world, there appear to be antigenic building blocks in the world of immunology. These antigens may be found in unrelated substances but provoke the same immune response in sensitive patients wherever they are found. Some of these shared antigens are currently described in the allergy literature. Banana, kiwi, chestnuts, and potatoes may elicit an immune response in a latex-sensitive person, for example, because they share antigens with latex. Apples, celery, carrots, potatoes, tomatoes and chamomile may provoke an immune response in a birch pollen-sensitive person because they too share antigens. In the same manner, roach-sensitive patients may also be sensitive to shrimp.
In order to select antigens for study the Institute maintains a large database of allergy patient skin-test results. Partial correlations are run on this database to select potentially cross-reactive antigens. Mesquite tree pollen correlated with over 60 other antigens, and laboratory testing was initiated to determine if this pollen demonstrated cross-reactivity. Using rabbit antibodies against mesquite pollen, we determined that mesquite cross-reacted with numerous deciduous trees.
In a study using mesquite-sensitized rabbits, there were so many mesquite cross-reactivities with various molecular weights of tree pollen proteins that it became clear that there could be more mesquite pollen allergens than had been described in the current literature. Using human sera sensitized to mesquite pollen, we determined there were at least thirteen human allergens of mesquite. Additional tree pollen research is planned to determine if mesquite allergens are as cross-reactive in human sera as there were in mesquite-sensitized rabbits.
The study of mesquite pollen cross-reactivity is a small part of the Institute's overall objective in the search for cross-reactive antigens. Increasing our knowledge of antigens which are shared over a broad spectrum of sources would allow us to educate patients so that they could avoid cross-reactive substances that complicate their health problems and dramatically reduce their quality of life.
Institute research is also expanding the concept of cross-reactivity from the narrow world of allergy to a broader world of immunology and hypersensitivity, theorizing that as an immune response matures over time, the antibodies formed against the original allergen will become less specific and more avid, thereby attacking not only the original target but those targets closely related. Over time, in a patient with a poorly-regulated immune system, this spreading phenomenon may manifest in increased sensitivity to the original allergen as well as an even greater range of reactivity to other antigens. Knowing how to neutralize a broad spectrum of allergies using only a few therapeutic molecules could be of real importance to both the allergic patient and the patient suffering from an immune disorder such as MS, rheumatoid arthritis, lupus, or other diseases reflecting regulatory dysfunction.
Moreover, increasing our knowledge of cross-reactivity in relation to hypersensitivities may also have dramatic application for the actual treatment of those diseases which have immune system components. By identifying antigens that are share a broad spectrum of reactions, it is possible that one extremely cross-reactive antigen might be used to neutralize a variety of immune diseases. For example, it is possible that mesquite could be used to treat allergies and immune disorders. Accordingly, this research forms a key building block in the Institute's research.
Please see Patents, Papers, and Presentations for articles on allergies by Institute researchers.
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