In vitro production of tumor necrosis factor-alpha by adherent human peripheral blood mononuclear cells incubated with killed coccidioidal arthroconidia and spherules

Abstract

We examined the in vitro production of tumor necrosis factor (TNF) by adherent human peripheral blood mononuclear cells (MNL) incubated with arthroconidia or spherules derived from the dimorphic fungus Coccidioides immitis. Using a bioassay measuring the percentage cytotoxicity of L929 cells, arthroconidia and spherules induced the production of measurable amounts of TNF by MNL. Both the arthroconidial and spherule preparations contained < 0.01 ng/ml of endotoxin, below that needed to induce cytotoxicity in the bioassay. Based on ELISA, the vast majority of TNF induced by arthroconidia or spherules was TNF-alpha, with minimal production of TNF-beta. These are the first data to show the production of TNF in human coccidioidomycosis.