USE OF A MONOCLONAL-ANTIBODY TO OVINE IGE FOR FLY STRIKE STUDIES IN SHEEP

A new monoclonal raised against sheep IgE was used to examine sera and wound exudates from sheep which had been struck by Lucilia cuprina in the field. The antibody was also used to detect the presence of IgE i n sera and skin sections from sheep which had been artificially infect ed with by larvae 3 times. Neither total, nor L. cuprina specific circ ulating IgE could be detected in serum or wound exudates from struck s heep. Cell bound IgE was, however, identified by the monoclonal in shi n sections from struck sheep and from a control sheep which had not be en struck. No difference in the number of IgE positive cells was obser ved between the control and 2 of the 3 artificially infected sheep, an d none of the latter showed an increase in IgE positive cells even aft er 3 infections. One sheep showed twice as many IgE positive cells as the other treated sheep and the third larval infection was difficult t o establish and limited in size and severity. This suggests a relation ship between innate resistance to strike and the number of IgE positiv e cells present in skin.