Complement-dependence of polymorphonuclear yeast cell phagocytosis: a comparison between man and various domestic animals.

The complement-dependence of polymorphonuclear yeast cell phagocytosis of sheep, goat, cattle, horse, dog, pig and man is determined by comparing the opsonizing abilities of untreated sera with complement-inactivated autologous sera at a serum concentration of 2.5% and at different phagocytosis periods. The performed phagocytosis assays only detects incorporated particles and allows for the differentiation of granulocytes with different quantities of phagocytosed particles. In sheep, horse and man the addition of heat-inactivated serum reduces the phagocytosis index to less than -80% of the value obtained at untreated serum addition at a phagocytosis period of 60 min. The other species show a smaller reduction ranging from -66.9% (dog) to 41.4% (cattle). The evaluation of the distribution pattern of granulocytes incorporating a certain number of yeasts offers significant differences in the investigated species.