Microbicidal activity of bone marrow cells. Augmentation of Candida killing activity of the cells by culturing with fibroblast conditioned medium

Characterization of Effector Cells with Anti-CandidaActivity Obtained from Murine Bone Marrow Cells Cultured in the Presence of rhG-CSF: Comparison between Normal and CY-Treated Mice

Bone marrow cells (BMC) obtained from normal and cyclophosphamide (CY)-treated mice were cultured in the presence of recombinant human granulocyte-colony stimulating factor (rhG-CSF) and their effector cell activities inhibiting growth of C. albicans were examined. When BMC from CY-treated mice were preincubated with 0.05 ng/ml of rhG-CSF, effector cells with enhanced anti-C. albicans activity were recovered in the adherent cell population, whereas anti-C. albicans activity of BMC from normal mice was found in the non-adherent cell population. During culture without the presence of rhG-CSF, nonadherent BMC, seemingly granulocytes, from normal mice showed apoptotic change, but addition of rhGCSF clearly inhibited this change. On the other hand, when BMC from CY-treated mice were cultured with rhG-CSF, adherent cells as the main effector had the appearance of monocytes. These differences between the effectors with anti-C. albicans activity obtained from normal and CY-treated mice are discussed.

Effect of orally administered beta-glucan on macrophage function in mice

The effect of orally administered SSG, a beta-1,3-glucan obtained from the culture filtrate of the fungus Sclerotinia sclerotiorum IFO 9395, on the function of peritoneal macrophages in CDF1 mice was examined. Oral administration of SSG (20, 40, 80 or 160 mg/kg, daily for 10 consecutive days) enhanced the acid phosphatase activity of peritoneal macrophages. The greatest enhancing effect was observed at 80 mg/kg of SSG. Relatively long periods of administration (more than 10 consecutive days) were needed to induce significant enhancing effects. Phagocytic activity, candidacidal activity, hydrogen peroxide (H2O2) production and interleukin-1 (IL-1) production of peritoneal macrophages were also enhanced after the administration of SSG by the oral route (80 or 160 mg/kg). However, the durations of the activated state after completion of administration differed depending on the activity. Enhanced activity of lysosomal enzyme (acid phosphatase) was also shown in peritoneal macrophages taken from C3H/HeJ mice, which is a nonresponder strain to bacterial lipopolysaccharide (LPS). These results demonstrate that SSG given by the oral route can activate peritoneal macrophages in mice.

A novel bioaction of PAF: induction of microbicidal activity in guinea pig bone marrow cells

When guinea pig bone marrow cells were incubated in the presence of 10(-8) to 10(-6) M platelet activating factor (PAF) for 24 to 72 hr, microbicidal activity against Candida parapsilosis of cells was augmented. This augmentation was inhibited by PAF-specific antagonists, CV6209 or FR900452. PAF-specific binding sites with a high affinity were found on guinea pig bone marrow cells. Carrageenan or 2-chloroadenosine, reagents known to be preferentially cytotoxic to macrophages, abolished the microbicidal activity of PAF-treated bone marrow cells. Macrophages prepared from the peritoneal cavity, however, acquired no appreciable microbicidal action by treatment with PAF. These observations suggest that PAF may affect a class of guinea pig bone marrow cells through binding to receptors specific to PAF, resulting in activation and/or induction of differentiation of monocyte-macrophage lineage cells.

Protecting effect of chitin and chitosan on experimentally induced murine candidiasis

Chitin and chitosan were found to exhibit a protective effect on mice administered these polysaccharides intraperitoneally against infection of the viable cells of Candida albicans NIH A-207 strain. A significant difference was observed between the protective effects of chitin and chitosan, i.e., chitin was much more effective than chitosan when the C. albicans cells were challenged via the intravenous route. In intraperitoneal inoculations of C. albicans cells, however, chitosan provided stronger resistance for mice than chitin. It has also been revealed that the number of polymorphonuclear leukocytes from circulating blood of chitin-administered mice increased remarkably compared with that of untreated and chitosan-treated mice, and that the increase of active oxygen-generating phagocytic cells was significant. On the other hand, the number of peritoneal exudate cells (PEC) and the amounts of active oxygen generated from these cells in chitosan-treated mice were larger than those of chitin-treated mice. However, candidacidal activities of PEC per fixed cell number in mice treated with chitin or with chitosan were almost the same and greater than those of untreated mice.