Eosinophils, in Asthma

Dahl, R, Venge, P. and Fredens, K. (1987). The eosinophil. In Asthma Basic Mechanisms and Clinical Management (eds P.J. Barnes, I. Rodger and N. Thomson), pp. 115-130. Academic Press, London. 

Wills-Karp, M. and Karp, C.L. (2004) Biomedicine. Eosinophils in asthma remodeling a tangled tale. Science, 305, 1726-1729. 

Siroux V. Curt F. Oryszczyn MP, Maccario J, Kauff-mann F Role of gender and hormone-related events on IgE. atopy, and eosinophils in the Epidemiological Study on the Genetics and Environment of Asthma, dO bronchial hyperresponsiveness and atopy. J Allergy Clin Immunol 2004 114 491-498. 

Inflammation is present in the lungs of all smokers. It is unclear why only 15% to 20% of smokers develop COPD, but susceptible individuals appear to have an exaggerated inflammatory response.5 O The inflammation of COPD differs from that seen in asthma, so the use of anti-inflammatory medications and the response to those medications are different. The inflammation of asthma is mainly mediated through eosinophils and mast cells. In COPD the primary inflammatory cells include neutrophils, macrophages, and CD8+ T lymphocytes. 

Robinson DS, North J, Zeibecoglou K, et al. Eosinophil development and bone marrow and tissue eosinophils in atopic asthma. Int Arch Allergy Immunol 1999 118(2-4) 98-100. 

Zeibecoglou K, Ying S, Yamada T, et al. Increased mature and immature CCR3 messenger RNA+ eosinophils in bone marrow from patients with atopic asthma compared with atopic and nonatopic control subjects. J Allergy Clin Immunol 1999 103(1 Pt 1) 99-106. 

Bousquet J, Chanez P, Vignola AM, Lacoste JY, Michel FB. Eosinophil inflammation in asthma. Am J Respir Crit Care Med 1994 150 S33-38. 

The latest studies show that reactive nitrogen species play even more important role in asthma development. It was found that exhaled nitrogen oxide, an indicator of eosinophilic airway inflammation, is drastically enhanced in asthmatic patients. Correspondingly, it has been shown that lung damage is characterized by the augmentation of nitrotyrosine and iNOS expression in neutrophils, eosinophils, and macrophages in the airways of asthmatic patients [266],... 

Bentley, A.M. et al., Activated T-lymphocytes and eosinophils in the bronchial mucosa in isocyanate-induced asthma, J. Allergy Clin Immunol., 89, 821, 1992. 

Trautmann A, Schmid-Grendelmeier P, Kruger K, Crameri R, Akdis M, Akkaya A, et al T cells and eosinophils cooperate in the induction of bronchial epithelial apoptosis in asthma. J Allergy Clin Immunol 2002 109 329-337. 

Cellular pathophysiology of asthma. Top, Cross-section of the normal airway and the asthmatic ain/vay. Mediators released during the inflammatory process associated with asthma cause bronchoconstriction, mucus secretion, and mucosal inflammation and edema. These changes reduce the size of the airway lumen and increase resistance to airflow, which leads to wheezing and shortness of breath. Bottom, The multitude of inflammatory cells (macrophages, eosinophils, mast cells, neutrophils) and neurotransmitters implicated in asthma pathophysiology. 

A3 receptors are present on human eosinophils and couple to signalling pathways that lead to cell activation ( Kohno et al. 1996a Reeves et al. 2000). Despite this it has not proven easy to demonstrate the functional consequences of activation of these sites (Reeves et al. 2000). Nevertheless, the chronic inflammation in asthma is characterised by extensive infiltration of the airways by activated eosinophils (Holgate 1999 Pearlman 1999) and it remains possible that the elevated adenosine concentrations associated with asthma would contribute to eosinophil activation through stimulation of A3 receptors. In addition, it has been speculated that activation of A3 receptors may protect eosinophils from apoptosis (Gao et al. 2001). Thus, blockade of A3 receptors may reduce the numbers of eosinophils and their activation thereby reducing the pro-inflammatory burden in the lung. Consistent with this, following 6 weeks treatment of mild asthmatics with theophylline there was a... 

Nassenstein C, Braun A, Erpenbeck A, Lommatzsch M, et al. 2003. The neurotrophins nerve growth factors, brain derived neurotrophic factor, neurotrophin 3 and neurotrophin 4 are survival and activation factors for eosinophils in patients with allergic bronchial asthma. J Exp Med. 198 455-467. 

Nassenstein C, Braun A, Nockher WA, Renz H. 2005. Neurotrophin effects of eosinophils in allergic inflammation. Curr All Asthma Rep. 5 204-211. 

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