Demonstration by in situ hybridization of dissimilar IL-1β gene expression in human alveolar macrophages and blood monocytes in response to lipopolysaccharide

J. F. Bernaudin, K. Yamauchi, M. D. Wewers, M. J. Tocci, V. J. Ferrans, R. G. Crystal

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

IL-1β is the major form of IL-1 produced by mononuclear phagocytes. To evaluate the possible mechanisms underlying the observation that mature populations of human mononuclear phagocytes as alveolar macrophages are relatively poor IL-1 producers compared with blood monocytes, the expression of the IL-1β gene mRNA transcripts was evaluated in LPS-stimulated autologous blood monocytes and alveolar macrophages by using a IL-1β cDNA probe. Although Northern analysis demonstrated that stimulated monocytes and alveolar macrophages both express 1.8-kb IL-1β mRNA transcripts, cytoplasmic dot blot analysis showed that the total IL-1β mRNA content in alveolar macrophages was only 38 ± 5% of that in blood monocytes. In situ hybridization with antisense and sense IL-1β RNA probes demonstrated that whereas most of stimulated blood monocytes contained IL-1β mRNA transcripts, a significant proportion of autologous alveolar macrophages stimulated in an identical fashion did not express the IL-1β gene. Within 4 h after LPS stimulation, IL-1β mRNA transcripts were detected in 81 ± 6% monocytes, whereas only 16 ± 9% of alveolar macrophages were positive, and by 18 h this had increased only to 43 ± 15%. Quantification of the size distribution of the IL-1β mRNA expressing mononuclear phagocytes demonstrated that, among the population of alveolar macrophages, the cells expressing this gene were not confined to those that were 'monocyte-like'. These observations demonstrate that there is a heterogeneity among population of mononuclear phagocytes in their ability to express the gene for IL-1β, which could explain the differences observed in IL-1 production.

Original languageEnglish
Pages (from-to)3822-3829
Number of pages8
JournalJournal of Immunology
Volume140
Issue number11
Publication statusPublished - 1 Jan 1988

    Fingerprint

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Cite this