Motion Picture Studies on Degranulation of Horse Eosinophils During Phagocytosis

Abstract

I t was shown in the preceding report (1) that eosinophil granules are lysosome-like structures, similar in m a n y regards to cytoplasmic granules of rabbit polymorphonuclear leucocytes. Lysis of granules in intact polymorphonuclear leucocytes during phagocytosis has recently been demonstrated (2). The present study was designed to determine whether or not eosinophil granules also disrupt during phagocytosis. MethodsEosinophils were separated from mixed horse leucocytes by sedimentation through 36 per cent albumin as described in the accompanying paper (1). They were then washed 3 times in physiological saline and finally suspended in saline at approximately 108 per ml, The suspension was held at room temperature in a stoppered lusteroid tube.Serum was obtained from fresh clotted horse blood. Frequently the serum was adsorbed with glass powder prior to use. 10 ml serum was mixed with 1 gm of 325 mesh borosilicate glass powder over the course of 1 hour at room temperature, followed by centrifugation at 100 g for 10 minutes to remove the glass. On some occasions phenol red indicator was added to the serum to permit adjustment of the pH to approximately 7 with CO2.Immune serum was obtained from a horse which had been injected weekly X 5 intravenously with 5 ml volumes of human red cells or of yeast cell walls (zymosan). Human red cells were washed thrice in saline and a 5 per cent suspension was then prepared. Zymosan (Standard Brands, Inc., New York City) was boiled in physiological saline, washed on the centrifuge three times, and finally suspended at 10 nag per ml in saline. Horse serum containing precipitating antibodies against human albumin was obtained from Sylvana Chemical Company, Orange, New Jersey. Heat inactivation of serum was for 30 minutes at 56°C.The particulates to be engulfed included: (a) human red cells from the same person whose red cells were employed to immunize the horse, (b) zymosan, and (c) an antigen-antibody precipitate prepared by mixing 1.5 mg of crystalline human albumin with 1 ml of horse antihuman albumin serum, followed by centrifugafion and three washings in saline.Thin 1~eparatlons on glass slides were made as described previously (2). Slides and coverslips were coated with formvar by dipping them into a 0.2 per cent solution in ethylene dichlo-

Generalized Equine Cutaneous Mastocytosis

“…Histamine [2] is chemotactic for eosinophils, and by analogy we infer that this explanation is rational in this case. It appeared that eosinophils degranulated [3] in the lesions associated with necrosis of collagen fibers. The accumulation of granules in necrotic collagen occurs in other mammalian mast cell lesions Cutaneous mast cell lesions in mammals are established as neoplastic [lo], inflammatory [5], and immunologic [7] in origin.…”

Bronchial Eosinophilia in Rhesus Monkeys with IgE Mediated Respiratory Responses

“…Certain studies [11,12,13] indicate that eosinophilotaxis is due to histamine while others [14,15,16] indicate no relation ship. Another possibility is that IgE-antigen complexes may be eosinophilotactic as in the use of other antigen-antibody complexes for induction of experimental eosinophilia [17,18,19]. It is possible that the rhesus ascaris respiratory system may provide a different method for determining the mechanism of the eosinophilic response, particu larly if improved sampling techniques can be developed.…”

Allergen Binding to Human Peripheral Leukocytes

“…The first type of eosinophil can be visualized entering the site of the allergic reaction with a specific immunologic function, i. e. to bind allergen and perhaps to release chemical mediators. The second type of eosinophil (without specific immunologic function), would enter the site of the allergic reaction with the role of non-specific phagocytosis [14,15]. Perhaps both types of the eosinophils are present in the nasal mucous during pollenation season performing these suggested functions.…”