Characterization of monoclonal antibodies against infectious laryngotracheitis virus

Nine monoclonal antibodies (MCAs) produced against two different strains of infectious laryngotracheitis virus (ILTV) were characterized and compared to previously characterized MCA 131-6, produced against a third ILTV strain. In western blotting experiments, MCAs C, E, and 11 resembled MCA 131-6, detecting proteins of 205, 160, 115, and 90 kD as well as several proteins less than 49 kD. The other six MCAs differed from previously described ILTV MCA. MCA D detected a 90-kD protein along with several less than 49 kD. MCAs 4 and 5 each detected proteins of 205, 160, 100, 90, and 70 kD. MCA 9 detected the same proteins detected by MCAs 4 and 5 except the 160-kD protein. MCA 10 detected proteins of 100, 90, and 70 kD and several proteins less than 49 kD. MCAs C, D, and E, like MCA 131-6, failed to react with any ILTV grown in the presence of tunicamycin, suggesting that those MCAs are specific for carbohydrate-based epitopes. MCA 6 reacted with only a 100-kD protein in the presence or absence of tunicamycin. The remaining MCA detected only a 70-kD protein in the presence of tunicamycin except MCA 5, which reacted with proteins of 70 and 90 kD. Only MCA 4 and 6 neutralized ILTV infectivity.