The Journal of Immunology, Vol 139, Issue 6 1873-1879, Copyright © 1987 by American Association of Immunologists

ARTICLES

Lipopolysaccharide and interleukin 1 inhibit interferon-gamma-induced Fc receptor expression on human monocytes

WP Arend, JT Ammons and BL Kotzin

The objectives of these studies were to study the effects of bacterial lipopolysaccharide (LPS) on interferon-gamma (IFN-gamma)-induced Fc receptor expression on human monocytes and to examine whether these effects were mediated through stimulation of interleukin 1 (IL-1) production. Fc receptor expression was determined by binding of monomeric monoclonal murine immunoglobulin (Ig)G2a and cytofluorographic analysis. IL-1 activity in monocyte supernatants and lysates was assayed by augmentation of mitogen-induced murine thymocyte proliferation. IFN-gamma induced the expression of Fc receptors on human monocytes that were specific for murine IgG2a. This induction was inhibited by the addition of LPS in amounts as low as 2 to 8 pg/ml. LPS inhibition of IFN-gamma-induced Fc receptor expression was paralleled by the appearance of IL-1 in monocyte lysates and supernatants. The addition of purified human or recombinant IL-1 beta at the initiation of culture similarly inhibited the expression of IFN-gamma-induced Fc receptors on the monocytes. LPS also inhibited Fc receptor expression on the human myelomonocytic cell line THP-1 after induction with IFN- gamma or phorbol myristate acetate alone or with both agents together. This inhibition also was paralleled by the production of IL-1 but the addition of exogenous IL-1 to the THP-1 cells had no effect on IFN- gamma-induced Fc receptor expression. Tumor necrosis factor (TNF) inhibited IFN-gamma-induced Fc receptor expression on human monocytes but was much less potent than comparable amounts of IL-1. TNF also did not inhibit Fc receptor expression on THP-1 cells. In fact, IL-1 or TNF led to an enhancement in IFN-gamma-induced Fc receptor expression on THP-1 cells. These results indicate that LPS can inhibit IFN-gamma- induced Fc receptor expression on human monocytes and that IL-1 and TNF may mediate these effects of LPS. Thus, an autocrine or paracrine role is suggested for these cytokines. The possibility exists that intracellular IL-1 resulting from LPS stimulation may be at least in part responsible for inhibition of Fc receptor expression.

This article has been cited by other articles:

				N. L. Webster, K. Kedzierska, R. Azzam, G. Paukovics, J. Wilson, S. M. Crowe, and A. Jaworowski Phagocytosis stimulates mobilization and shedding of intracellular CD16A in human monocytes and macrophages: inhibition by HIV-1 infection J. Leukoc. Biol., February 1, 2006; 79(2): 294 - 302. [Abstract] [Full Text] [PDF]

				M. Beigier-Bompadre, P. Barrionuevo, F. Alves-Rosa, C. J. Rubel, M. S. Palermo, and M. A. Isturiz N-Formyl-Methionyl-Leucyl-Phenylalanine Inhibits both Gamma Interferon- and Interleukin-10-Induced Expression of Fc{gamma}RI on Human Monocytes Clin. Vaccine Immunol., March 1, 2001; 8(2): 402 - 408. [Abstract] [Full Text] [PDF]