Effects of carbon dust inhalation on the cell mediated immune response in mice

Abstract

The effects of carbon dust inhalation on the bone marrow derived (B) and thymus derived (T) lymphocyte populations of spleen and mediastinal lymph node (MLN) cultures were examined. The concanavalin A (Con A) responsive cell population (T cells) in the spleen was found to be depressed after 7 days of preexposure to carbon dust. However, this effect was transient and after 14, 21, and 28 days of preexposure to carbon dust, the Con A responsive cells exhibited a 30 to 40% enhancement over control group responses. Conversely, Con A responsive cells in the pooled MLN cultures exhibited depression, ranging from 22 to 33% below control group values, after 7, 14, and 28 days of preexposure to carbon dust. The lipopolysaccharide (LPS) responsive cell population (B cells) in the spleens of carbon exposed mice was found not to differ significantly from control group values after all times of preexposure. LPS responsive cells in the MLN cultures exhibited enhancement ranging from 49 to 74% above control values, after 14, 21, and 28 days of preexposure to carbon dust. The ability of carbon spleen cell cultures from carbon exposed mice to undergo antigen induced blast transformation after sensitization with Mycobacterium tuberculosis H37Ra was also determined. Mice exposed to carbon dust inhalation 2 weeks before and 3 weeks after aerosol or subcutaneous immunization exhibited significantly enhanced ratios of transformation upon culture of their spleen lymphocytes with purified protein derivative of tuberculin.