Effect of cytokines on anticryptococcal activity of human microglial cells

Abstract

The effect of selected cytokines on the antifungal activity of human microglia was studied with encapsulated and acapsular strains of Cryptococcus neoformans. None of the cytokines tested increased the fungistatic activity of microglia, suggesting that killing of cryptococci within the central nervous system is dependent on other host defense mechanisms.

FIG. 1

Growth inhibition of encapsulated (NIH 37) and acapsular (NIH 3413) C. neoformans by human microglia. Growth inhibition is expressed as percent growth relative to cryptococcal growth at 24 h in cultures that did not contain microglia (control). Microglia were either not treated with cytokines or stimulated with IFN-γ (200 U/ml), GM-CSF (10 ng/ml), or a combination of both cytokines for 24 h prior to constitution of phagocytosis mixtures. Data represent means ± standard errors of the means of five (NIH 37) and three (NIH 3413) separate experiments with cells from different brain tissue specimens.