Document Type


Publication Date



School of Medicine




A number of environmental factors can affect the development and severity of allergy and asthma; however, it can be argued that the most significant inhaled agents that modulate the development of these conditions are biologics. Sensitization to environmental allergens is an important risk factor for the development of asthma. Innate immune responses are often mediated by receptors on mononuclear cells whose primary ligands arise from microorganisms. Many pathogens, especially viruses, target epithelial cells and affect the host immune response to those pathogens. The acquired immune response to an allergen is influenced by the nature of the innate immune system. Products of innate immune responses to microbes promote TH1-acquired responses. In the absence of TH1 responses, TH2 responses can dominate. Central to TH1/TH2 balance is the composition of contaminants that derive from microbes. In this review we examine the biology of the response to allergens, viruses, and bacterial products in the context of the development of allergy and asthma.

Source Citation

Zeldin, D. C., Eggleston, P., Chapman, M., Piedimonte, G., Renz, H., & Peden, D. (2006). How Exposures to Biologics Influence the Induction and Incidence of Asthma. Environmental Health Perspectives, 114(4), 620–626.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.