Influence of gender and age on course of infection and cytokine responses in mice with disseminated Cryptococcus neoformans infection.

Objective: To study the influence of gender and age on the course of infection and the cytokine response in a murine model of disseminated cryptococcosis.

Methods: The course of the infection (survival and fungal load in blood and tissues) as well as pro-inflammatory and anti-inflammatory cytokine responses in plasma and organs were compared according to gender and age in outbred mice previously infected with Cryptococcus neoformans NIH52D.

Results: Although survival and fungal load were similar in male and female mice, the expression of all cytokines in plasma and of tumour necrosis factor-alpha and interferon-gamma in spleen was significantly increased in female mice compared to male mice in two independent experiments. Young male mice had a significantly shortened survival, were significantly more infected and had predominant tumour necrosis factor-alpha and interferon-gamma responses in comparison with older male mice.

Conclusion: Host factors should be taken into account when studying the immune response to experimental C. neoformans infection. Our data support epidemiological and clinical data showing differences in susceptibility to cryptococcosis according to gender and age.