Modifying factors on phagocytosis of polymorphonuclear allergic subjects.

Supernatants from pollen-activated cultures of mononuclear (MN) cells obtained from two subjects allergic to gramineae pollen were tested for their effect on phagocytic activity of human polymorphonuclear leucocytes (PMN). An enhancement of phagocytosis was observed. Similarly prepared supernatants from MN cells of non-allergic control subjects did not affect PMN phagocytic activity. On the basis of these findings it is suggested that in the presence of allergen, cultures of MN cells from pollen-sensitized subjects produce a substance that stimulates PMN phagocytic activity. The direct effect of pollen on PMN was also studied. The allergen caused an inhibition of phagocytosis by PMN from allergic subjects. Pollen had no effect on phagocytosis by PMN from non-allergic control subjects.