Specifically, culture conditions resulting in a 1,2-β-mannosyl linkage within the mannan moiety of these fractions significantly reduced the biological effects described above (15). This finding was also supported by investigations into the activity and structure of cell wall mannan extracts of C. albicans, the structures Silmitasertib chemical structure of which vary with changes in culture conditions such as culture media and growth temperatures (9). Numerous studies have reported that the cell wall mannan of Candida species

is altered by various culture conditions such as growth temperature (18), pH (19), oxidative stress, and osmotic pressure (20). However, pathogenic activities in terms of induction of vasculitis and acute anaphylactoid shock of other Candida species, such as C. metapsilosis, have not been investigated. We thought that polysaccharide fractions from C. metapsilosis might induce such activity because it is well known that the cell mannan of C. metapsilosis is not expressed as 1,2-β-mannan within its mannan moiety (21). In the present study, we examined whether the secreted polysaccharide fraction from another Candida species, C. metapsilosis, which is less pathogenic than C. albicans, can induce vasculitis similar to that found in KD, and anaphylactoid shock, in mice in the same

way as C. albicans does. We obtained the MLN8237 secreted polysaccharide fraction from C. metapsilosis; assessed its pathogenic activities, such as induction of vasculitis and acute anaphylactoid shock; and analyzed its mannan structure. Male ICR and DBA/2 mice (6 weeks old) were purchased from Japan SLC (Hamamatsu, Japan). The mice were housed in a specific pathogen-free environment. All animal experiments followed

the guidelines for laboratory animal experiments of the Tokyo University of Pharmacy and Life Sciences, and each experimental protocol was approved by the committee for laboratory animal experiments at this institution. The completely synthetic medium, C-limiting medium (22) contained (per liter): sucrose 10 g, (NH4)2SO4 2 g, KH2PO4 2 g, CaCl2·2H2O 0.05 g, MgSO4·7H2O 0.05 g, ZnSO4·7H2O 1 mg, CuSO4·5H2O 1 mg, FeSO4·7H2O 0.01 g, and biotin 25 μg (final pH, 5.2). The Candida Check was from Mitsubishi Calpain Kagaku Iatron (Tokyo, Japan). Candida metapsilosis NBRC 1068 was obtained from the NBRC (Chiba, Japan). CMWS was prepared from C. metapsilosis NBRC 1068 in accordance with slightly modified conventional methods (10). The procedure used was as follows: 4 L of medium (C-limiting medium) was added to a fermenter and cultured for 2 days at 27°C with air supplied at a rate of 4 L/min. Following culture, an equal volume of ethanol was added. After the mixture had been left to stand overnight, the precipitate was collected. The precipitate was suspended in 250 mL of distilled water, and the water-soluble fraction collected. Ethanol was added to the soluble fraction, and the mixture allowed to stand overnight.