Effective inhibition of Candida albicans growth by the combination of murine peritoneal neutrophils and activated macrophages.

The effect of leukocytes on the anti-Candida activity of neutrophils was examined. Murine neutrophils which were purified from casein-induced peritoneal cells inhibited the mycelial growth of Candida albicans. This anti-Candida activity of neutrophils was augmented by the addition of spleen cells prepared from mice pretreated with bacterial lipopolysaccharide 3 hr before, but not from non-treated mice. The population in the spleen cells, which enhanced the anti-Candida activity of neutrophils, was plastic-plate adherent, nylon-fiber columns adherent and anti-Mac-1 antigen-positive. These immunological profiles suggested that the enhancing cells are classified to splenic macrophages. Peritoneal-exudated macrophages from mice treated with lipopolysaccharide also augmented the anti-Candida activity of neutrophils. These results suggest that the anti-Candida activity of neutrophils may be upregulated by activated macrophages.

[Reverting effect of cysteine on the suppression by glucose or dexamethasone of anti-Candida activity of human neutrophils].

Amino acid mixture prescribed for an hyperalimentation solution (PN-twin) diminishes suppression of anti-Candida activity of neutrophils as reported previously (Tansho, T, et al. J. Jpn. Assoc. Infect. Dis. 70: 463-469). The aim of this study was to identify the active principle in the amino acid mixture and to examine its action mechanism. Amino acid mixture (PN-twin) containing 23 amino acids neutralized the suppression of anti-Candida activity of human neutrophils by 1.0% of glucose. These amino acids were divided to several groups by their structure and effects of the groups on the suppressed anti-Candida activity neutrophils were examined. In all groups tested, amino acids containing cystein and methionine clearly neutralized the suppression, especially cysteine at the concentration more than 20 micrograms/ml significantly recovered the anti-Candida activity of neutrophils which was suppressed in the presence of 1% glucose or 10(-6) M dexamethasone. Correspondingly, cysteine augmented production of lactoferrin by stimulated neutrophils; which functions as a major effector molecule in growth inhibition of Candida by neutrophils. These results suggest that cysteine in alimentation solution augments anti-Candida defense mechanisms through recovery of neutrophil function.

[Inhibition of mycelial growth of Candida albicans by ascites fluid of tumor bearing mice].

The effects of ascites fluids and sera of tumor-bearing mice on the mycelial growth of Candida albicans were examined. When the ascites fluids or the sera obtained from mice inoculated with MM46 mammary carcinoma were added to the culture medium, mycelial growth of C. albicans was strongly inhibited. The molecular size of the growth inhibitory factor in the ascites fluids was estimated to be approximately 80 K dalton by gel-filtration chromatography. Ferric chloride (6 microM) neutralized the anti-Candida activity. On the basis of these results including morphological observation, a possible role of a transferrin-like molecule was discussed.

[Suppression of anti-Candida activity of human neutrophils by glucose and diminishment of the glucose effect by an amino acid mixture].

Effects of a glucose and amino acid mixture prescribed for parenteral alimentation on anti-Candida activity of neutrophils were examined. Neutrophils obtained from peripheral blood of healthy humans inhibited the growth of Candida albicans in vitro. More than 1.0% of glucose inhibited the anti-Candida activity of the neutrophils in a dose-dependent manner. This glucose effect was reduced by the addition of an amino acid mixture clinically prescribed with a carbohydrate solution (PN-twin) in Japan. The amino acid mixture neutralized the suppression of anti-Candida activity of neutrophils by dexamethasone. These results suggest that an amino acid mixture prescribed in an alimentation solution may play a role as a neutralizer of the suppressive action of glucose for anti-Candida activity of neutrophils in a limited area near the top of a catheter in a blood vessel.