EXPERIMENTAL BACTERIAL KERATITIS - A QUANTITATIVE MODEL OF LEUKOCYTE MIGRATION FOLLOWING TRANSFUSION

Abstract

A model for the study of polymorphonuclear leukocyte (PMN) migration, after transfusion employing induction of keratitis in guinea pigs, was developed. Initial studies demonstrated that, compared with other agents, intracorneal injection of Pseudomonas aeruginosa following in vivo labeling of PMN by administration of 3H-thymidine produced the greatest influx of radiolabeled PMN into corneas. In subsequent studies, donor peritoneal PMN were radio-labeled by injection of donors with 3H-thymidine. Neutropenia was induced in recipients by whole body irradiation, and they (the recipients) were infected intracorneally with Pseudomonas prior to transfusion. Corneal radioactivity was assayed 24 h after induction of keratitis and the number of donor PMN in corneas was calculated. Half-life of transfused PMN in non-neutropenic recipients was 1.9 h. Arrival of labeled PMN at infected corneas in recipient animals ranged between 0.1-1.0% of transfused cells. Exposure of donor PMN to sonication or to 45.degree. C for 20 min reduced the proportion of PMN arriving at infected corneas (P < 0.001). Storage of PMN for 24 h at 4.degree. C led to a greater ingress of donor PMN compared with storage at 37.degree. C (P < 0.01). This model allows quantitation of in vivo PMN function after transfusion, and should allow assessment of the effects of most aspects of PMN transfusion technique upon such function.