Influence of yeasts and of their constituents on nucleoside uptake in peritoneal murine macrophages

A marked reduction of [3H]-uridine uptake was observed when mouse peritoneal macrophages (pM phi) were exposed to heat-killed Candida albicans or Saccharomyces cerevisiae. By contrast, an increased nucleoside uptake was promoted by yeast products such as zymosan, laminarin, or yeast cell-wall extracts, which are mainly composed of beta-glucans and alpha-mannans. In a search for the active fungal component(s), the uptake process was shown to be differently affected by monosaccharides and polysaccharides. These findings support the view that a specific recognition of a pM phi membrane receptor is mediating the effect of the various substances.