Lectin-induced giant cell formation in the chicken wattle.

The fusion of mononuclear cells has been observed in inflammatory reactions and in cell culture experiments. This report describes the in vivo fusion of macrophages and their cytological structures. Thick (1 micrometer) and thin sections of wattle were prepared 6, 12, 24, 48, and 96 hr after a single subcutaneous-wattle injection of phytohemagglutinin (PHA-P; .1 ml; 100 microgram) in saline. The injection of PHA-P induced withn 6 hr a blood borne mononuclear cell infiltration of the chicken's wattle. Giant cells (3 to 8 mononuclear cells) were found by 24 hr, reached a maximum number by 48 hr and declined perceptibly by 96 hr. After 48 hr the mononuclear cells possessed a well-developed Golgi apparatus, ergastroplasmic cisternae, and large amounts of glycogen-like granules which diminished by 96 hr. The influence of lectin on the glycogen content of macrophages is similar to published observatins on small lymphocytes and suggests a similar carbohydrate metabolism between these two cell types.