Functional abnormalities in the beige mouse eosinophil assessed using T. spiralis as a target.

These studies on eosinophils from beige mice have shown that such cells possess morphologically abnormal granules and that they also have an impaired capacity to interact in vitro with a non-phagocytosable target such as the infective larva of Trichinella spiralis. However, beige mice with these functionally abnormal eosinophils are able to control a T. spiralis infection as well as the normal heterozygote mice. A morphological study of beige eosinophils revealed the presence of structurally distinct lysosomal secretion granules. Some resembled granules in normal eosinophils while others were grossly enlarged and contained multiple crystalloids. When these peritoneal eosinophils were allowed to interact with T. spiralis in vitro in the presence of specific antibody and/or complement, they behaved differently. Cells containing only large granules adhered loosely and temporarily; they were not observed to degranulate. In contrast, cells containing a mixture of granules, or only small granules were able to adhere and degranulate. Despite the defects in the eosinophils of beige mice, the course of an infection with the nematode parasite T. spiralis in beige animals was similar to that in normal animals. Therefore, if eosinophils are crucial in the control of this infection as suggested from other studies, the defect in beige eosinophils is not sufficient to prevent an apparently normal response to the parasite.