Effects of fly ash inhalation on murine immune function: Effects on systemic response

Abstract

Mice were exposed to fly ash at levels ranging from 728–2221 μg/m 3 respirable for varying periods of time, and several immunological parameters were measured. Little change was noted in splenic response to mitogens or cytolytic ability. Splenic lymphocytes from fly ash-exposed mice incorporated significantly more thymidine following subcutaneous sensitization with BCG, although no differences were noted in response of these lymphocytes to PPD. Fly ash exposure of greater than 1 week caused a suppression of antibody response to aerosols of Escherichia coli in the spleen, but not in the mediastinal lymph nodes. Following 3–4 weeks of fly ash exposure, no changes in splenic antibody responses were noted following intravenous injections of LPS or intratracheal injections of DNP-Ficoll. However, after 9 months exposure at higher concentrations of fly ash, splenic plaque-forming responses were significantly suppressed after both aerosol and intratracheal exposure to antigen.