Production of tumor necrosis factor-alpha in granulocytopenic mice with pulmonary candidiasis and its modification with granulocyte colony-stimulating factor

Abstract

In the present study, a lethal model of pulmonary candidiasis was established using granulocytopenic mice with cyclophosphamide. These mice started to die 1 day after infection and had all died within the next 48 hr. The counts of live C. albicans in the lung gradually increased with time, while the organisms were quickly eliminated in the normal mice. From the histology and measurements on bronchoalveolar lavage fluid (BALF), polymorphonuclear cells (PMN) response was almost zero up to 24 hr; and then a weak but significant response was observed at 48 hr, while a marked accumulation of PMN was detected from as early as 6 hr in normal mice. In contrast, macrophages had accumulated in BALF by 48 hr in granulocytopenic mice, but not in normal mice. Both in serum and BALF, a considerable level of tumor necrosis factor-alpha (TNF-alpha) was detected from 6 hr, peaking at 24 to 48 hr, while in normal mice the quantity was under the detection limit in serum and very low in BALF. The effects of administering granulocyte colony-stimulating factor (G-CSF) on these parameters were next examined. G-CSF significantly prolonged the survival time of granulocytopenic mice, promoted the clearance of organisms through increasing the counts of PMN in the lung, and strongly inhibited the production of TNF-alpha both in BALF and serum. These results suggest that this cytokine does not protect them, but plays some role in their death due to candidial infection in granulocytopenic mice.