Alveolitis caused by exposure to coal mine dusts: Production of interleukin-1 and immunomodulation by bronchoalveolar leukocytes

Abstract

Two kinds of coal mine dust, low rank with high quartz (bituminous) and high rank with low quartz (anthracite), were assayed for ability to induce alveolitis and to stimulate interleukin-1 release from normal alveolar macrophages in vitro. Dust-elicited bronchoalveolar leukocytes were also assessed for their effects on macrophage-depleted splenocyte mitogenesis and their ability to produce interleukin-1. Quartz and titanium dioxide were used for comparison as toxic and inert dusts, respectively. Both coal mine dusts caused substantial release of interleukin-1 from normal alveolar macrophages in vitro and the levels were higher than those caused by quartz. Bituminous coal mine dust provoked acute but rapidly subsiding macrophage/neutrophil alveolitis which was greater than that provoked by titanium dioxide; anthracite caused less alveolitis than titanium dioxide and quartz caused large scale, persistent alveolitis. Whole bronchoalveolar leukocytes, including polymorphonuclear neutrophils, elicited by exposure to dust, were less inhibitory to lymphocyte mitogenesis than normal alveolar macrophages and bituminous coal mine dust-induced neutrophils were augmentary to lymphocyte mitogenesis; macrophages from inflamed lungs were, on the whole, inhibitory to lymphocyte mitogenesis. Alveolar macrophages from bituminous coal mine dust- or titanium dioxide-exposed lungs showed increased ability to release interleukin-1 on stimulation in vitro. These findings suggest that bronchoalveolar leukocytes elicited by coal mine dust could modulate immunity by means of interleukin-1 release and enhancement of lymphocyte proliferation.