Down-regulation of K cell activity by neutrophils

F. Dallegri, F. Patrone, G. Frumento, A. Ballestrero, C. Sacchetti

Research output: Contribution to journalArticle

Abstract

Human neutrophils, activated by phorbol-myristate acetate (PMA), (A-neutrophils), were found to suppress lymphocytic killer (K) cell-mediated antibody-dependent cellular cytotoxicity (ADCC). Resting (R) neutrophils, ie, PMA-untreated cells, were completely ineffective. Suppression was optimal when A-neutrophils were added at the beginning of the ADCC assay. Furthermore, A-neutrophils were found to cause an approximately 80% reduction in the number of Raji target cell-bound lymphocytes. These data indicate that A-neutrophils inhibit K cell activity by interfering with the target cell recognition. A-neutrophils were capable of reducing the percentage of Fc receptor (FcR)-bearing lymphocytes with a half-time of 7.2 minutes, through a process preventable by the serine-protease inhibitors tosyl-lysine-chloromethyl ketone (TLCK) and lima bean trypsin inhibitor (LBTI). Conversely, A-neutrophils caused a very slow decrease in the amount of Raji cell-bound antibodies, as detected by the complement-mediated lytic assay. Thus, only lymphocyte FcR structures seem to be highly susceptible to neutrophil-derived TLCK- and LBTI-inhibitable proteases. Furthermore, supernatants from A-neutrophils were found to inhibit K cell ADCC and lymphocyte binding to Raji target cells. In addition, LBTI prevented the A-neutrophil-dependent and the supernatant-dependent inhibition of both K cell ADCC activity and lymphocyte-target cell conjugate formation. Together these data suggest that A-neutrophils suppress K cell function through a protease-mediated impairment of the FcR binding capacity. The results provide evidence that human neutrophils are endowed with mechanisms to regulate K cell ADCC activity.

Original languageEnglish
Pages (from-to)571-577
Number of pages7
JournalBlood
Volume65
Issue number3
Publication statusPublished - 1985

ASJC Scopus subject areas

  • Hematology

Fingerprint Dive into the research topics of 'Down-regulation of K cell activity by neutrophils'. Together they form a unique fingerprint.

  • Cite this

    Dallegri, F., Patrone, F., Frumento, G., Ballestrero, A., & Sacchetti, C. (1985). Down-regulation of K cell activity by neutrophils. Blood, 65(3), 571-577.