We first determined that the active component of MPF was heat stable and proteinase resistant. This strongly suggested that the component was either lipid or sugar in nature. We next optimized techniques to isolate lipids and sugars from F. tularensis for testing in our CLDC preparations. We confirmed, similarly to MPF, that in the absence of CLDC neither the lipid preparations nor the sugars were able to provoke protective immune responses directed against F. tularensis in host cells. We next combined the lipid preparations with CLDC to determine their efficacy against F. tularensis infection. However, as inorganic molecules the lipids are resuspended in ethanol. We found that ethanol had a profoundly negative effect on the retention of CLDC liposomes.
