Cryptococcus neoformans causes lipid peroxidation; therefore it is a potential inducer of atherogenesis

Abstract

Certain viral and bacterial species play a role in the development of atherosclerosis. Our hypothesis was that yeasts, such as Cryptococcus neoformans, also may be a cause of lipid peroxidation (LPO), which can lead to atherosclerosis. Rabbits were inoculated with heat-killed C neoformans several times during the first 6 wk in 10 wk observation. These tests were done at regular intervals: (i) blood cell count, (ii) the nitroblue tetrazolium (NBT) test on isolated neutrophils to determine their super oxide anion production and (iii) LPO of plasma. The histopathology of the lungs also was evaluated. In the inoculated rabbits we found an increase in the number of neutrophils in blood with an elevated NBT reduction, an increase in lipid peroxidation of plasma and bronchopneumonia with various types of inflammatory cells. Our findings suggest that the ability of C. neoformans to induce LPO in human asymptomatic carriers should be studied. Moreover the cryptococcal rabbit model we use rapidly induces LPO and may be of value in the assessment of therapy for atherosclerosis.

• atherosclerosis
• Cryptococcus neoformans
• lipid peroxidation
• neutrophils
• nitroblue tetrazolium reduction

The authors thank Elisabeth Berg, Medical Statistics Unit, Department of Learning, Informatics, Management and Ethics, for the statistical analyses. This study was supported by grants from Karolinska Institutet.