Membrane-bound and soluble alpha IL-5 receptor mRNA in the bronchial mucosa of atopic and nonatopic asthmatics

Am J Respir Crit Care Med. 1997 Apr;155(4):1413-8. doi: 10.1164/ajrccm.155.4.9105087.


Eosinophilic inflammation and interleukin-5 (IL-5) expression are characteristic features of the bronchial mucosa in asthma. We have investigated the differential expression of membrane and soluble isoforms of alpha IL-5 receptor (alpha IL-5Rm and alpha IL-5Rs) mRNA in asthmatics and in normal control subjects and examined the correlation between alpha IL-5Rm and alpha IL-5Rs expression and the FEV1 and airway hyperresponsiveness. Nineteen subjects with stable asthma (atopic = 9; intrinsic = 10) and 22 control subjects (atopic = 12; nonatopic = 10) were recruited. Endobronchial biopsies were obtained and processed for in situ hybridization and double-staining techniques. There was a significant increase in the number of cells per millimeter basement membrane expressing mRNA for total, membrane-bound, and soluble alpha IL-5R in asthmatics when compared with that in nonasthmatic control subjects (p < 0.001); 93% of the cells positive for alpha IL-5R mRNA were EG2+ve eosinophils. There was no significant difference in the expression of alpha IL-5Rm and alpha IL-5Rs between the atopic and nonatopic asthmatics. The expression of alpha IL-5Rm and alpha IL-5Rs was also nonsignificantly different between the atopic and nonatopic control subjects. However, in the asthmatic subjects, the number of positive cells expressing mRNA for alpha IL-5Rm inversely correlated with FEV1(r2 = 0.89, p < 0.001), whereas the expression of alpha IL-5Rs mRNA directly correlated with FEV1 (r2 = 0.52, p < 0.001). There were no significant correlations between alpha IL-5R isoforms and the methacholine PC20. These results suggest that alpha IL-5R upregulation and differential regulation of alternatively spliced alpha IL-5R mRNA transcripts may influence the eosinophil response and the accompanying changes in airflow limitation in both atopic and nonatopic variants of chronic asthma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Asthma / immunology
  • Asthma / metabolism*
  • Asthma / pathology
  • Biopsy
  • Bronchi / metabolism*
  • Bronchi / pathology
  • Case-Control Studies
  • Eosinophils / immunology
  • Eosinophils / metabolism*
  • Female
  • Gene Expression
  • Humans
  • Hypersensitivity, Immediate / immunology
  • Hypersensitivity, Immediate / metabolism*
  • Hypersensitivity, Immediate / pathology
  • In Situ Hybridization
  • Interleukin-5 / biosynthesis*
  • Male
  • Middle Aged
  • RNA, Messenger / genetics
  • Receptors, Interleukin / biosynthesis*
  • Receptors, Interleukin-5


  • Interleukin-5
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-5