Inhibition of natural killer activity by human bronchoalveolar macrophages

C. Bordignon, F. Villa, P. Allavena, M. Introna, A. Biondi, R. Avallone, A. Mantovani

Research output: Contribution to journalArticlepeer-review


Mononuclear phagocytes were isolated by adherence from peripheral blood, peritoneal exudates, early lactation milk, ovarian carcinomatous ascites and bronchoalveolar lavages. Their capacity to modulate natural killer (NK) activity was assessed by mixing them with blood lymphocytes and by measuring lysis of 51Cr-labeled K562 cells. Unlike other mononuclear phagocyte populations, alveolar macrophages caused a marked dose-dependent inhibition of NK activity. Significant inhibition (40%) of the expression of cytotoxicity was evident at a ratio of alveolar macrophages to lymphoid cells of 0.12:1, and more than 80% suppression was usually observed at a ratio of 0.5:1. Blood monocytes, peritoneal and milk macrophages were consistently inactive up to the highest ratio tested, 2:1. Inhibition of the expression of NK activity by alveolar macrophages was observed at lymphocyte to K562 ratios ranging from 6:1 to 100:1 and over a 4 h or 20 h 51Cr release asay. Alveolar macrophages also inhibited interferon-stimulated cytotoxicity. Alveolar macrophages are unique among the mononuclear phagocyte populations studied in their capacity to inhibit the expression of NK activity effectively, and they could play a role in determining the low levels of NK activity associated with human pulmonary tissue.

Original languageEnglish
Pages (from-to)587-591
Number of pages5
JournalJournal of Immunology
Issue number2
Publication statusPublished - 1982

ASJC Scopus subject areas

  • Immunology


Dive into the research topics of 'Inhibition of natural killer activity by human bronchoalveolar macrophages'. Together they form a unique fingerprint.

Cite this