Mechanisms underlying eosinophil trafficking and their relevance in vivo

D.C. Cara1, D. Negrao-Correa2 and M.M. Teixeira3

Departments of 1Pathology,2Parasitology and 3Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

Offprint requests to: Dr. M.M. Teixeira, Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, 31270.901 - Belo Horizonte, Minas Gerais, Brazil. Fax: +55 31 499 2695. e-mail: mmtex@icb.ufmg.br

Summary. After their formation in the bone marrow, eosinophils circulate with a short half-life and are distributed throughout the body, especially in mucosal and sub-mucosal regions. Although a small amount of these cells are normally seen in healthy tissue, blood and tissue eosinophilia is a hallmark of helminthic and allergic diseases. The role of eosinophils in the normal physiology of mucosal tissues is not understood, but there is good evidence to demonstrate that these cells protect the host at least against some intestinal helminths, specially those with a lung cycle. In addition, there are now many data that support a role for eosinophils in the pathophysiology of allergic diseases, such as asthma. Because helminthic diseases have been largely controlled in developed countries, there has been much interest in the development of drugs which affect eosinophil migration and/or activation in the tissue and which may, thus, be useful in the treatment of allergic conditions. The understanding of the mechanisms controlling eosinophil trafficking and/or activation are essential in the development of anti-eosinophil-based therapeutic strategies. The present paper reviews aspects of eosinophil biology with emphasis on the role of eosinophils in parasitic infections and allergy, the basic mechanisms underlying the trafficking of eosinophils into tissue and how these can be modulated pharmacologically. Histol. Histopathol. 15, 899-920 (2000)

Key words: Eosinophil, Allergy, Helminths, Trafficking, Interleukin-5, Cell adhesion molecules

DOI: 10.14670/HH-15.899