Protection afforded by immunization with <i>C. gattii</i> cell wall and cytoplasmic protein preparations.

<p>BALB/c mice were mock-immunized with endotoxin free PBS or immunized with total cell wall proteins (CW), cytoplasmic proteins (CP), or a combined CW and CP protein preparation (CW/CP) in 50 µl of sterile PBS by nasal inhalation. Mice were subsequently challenged with 10⁴ CFU of <i>C. gattii</i> strain R265 intranasally. Survival was monitored twice daily and mice that appeared moribund or not maintaining normal habits (grooming) were sacrificed (A). Survival data shown are cumulative of 2 experiments each using 8 and 6 mice per experimental group. Asterisk indicates significantly different (<i>**P<0.001</i>) survival rates for each immunized group compared to mock-immunized mice as assessed by the Log-rank (Mantel-Cox) test Alternatively, lungs were excised at days 7, 14, and 21 post-challenge and the pulmonary cryptococcal burden quantified (B). Pulmonary fungal burden data are cumulative of 3 experiments using 4 mice per time point. Results are expressed as mean CFU per milliliter ± SEM. Asterisks indicate where significant decreases (*<i>P</i><0.05), (**<i>P</i><0.001) and (***<i>P</i><0.0001) were observed compared to mock-immunized mice.