Examination of antigenic structure and some biological activities of hemagglutinin-neuraminidase (HN) and fusion (F) glycoprotein antigens of Newcastle disease virus, in vitro

Abstract

Objective of our study was examination of the antigenic structure, hemagglutinating and hemolytic activities of the surface glycoprotein HN and F antigens of purified ND viruses ( molecular weights of 63-65kD and 38-40kD) and glycoprotein subunits isolated from their outer envelopes (molecular weights of 62-64kD and 37-39kD) , activated with 0.025g/dl trypsin-versen, in vitro. The samples of activated purified virions and isolated glycoprotein subunits of ND virus with total protein concentrations of 0.23 and 0.16mg/ml and hemagglutinating titre of 256HAU/0.1ml, induced a hemolysis of chickens erythrocytes at the antigen dilutions of 1:64 and 1:128 per ml of the sample and expressed intensive hemagglutinating activities of 512 and 1024HAU/0.1ml, after their activation with trypsin-versen. After treatment of the aforementioned samples with specific hyperimmune sera against ND virus in which the hemagglutination-inhibition (HI) titre was 1:64, hemolytic activities were not registered. The results show that there are possibilities to use hemolytic test for the fast detection of immunologically important glycoprotein antigens of ND viruses and their identification with specific hyperimmune sera.

Cilj naših istraživanja je bilo ispitivanje antigenske strukture, hemaglutinacionih i hemolitičkih aktivnosti površinskih glikoproteinskih HN i F antigena prečišćenih virusa NDV (molekulske težine od 63-65kDa i 38-40kDa) i glikoproteinskih subjedinica izolovanih iz njihovih spoljašnjih omotača (molekulske težine od 62-64kDa i 37-39kDa), aktivisanih sa 0,025g/dl tripsin-versenom, in vitro. Uzorci prečišćenih viriona i izolovanih glikoproteinskih subjedinica virusa NDV sa ukupnim koncentracijama proteina od 0,23 i 0,16mg/ml i hemaglutinacionog titra od 256 HJ/0,1ml, indukovali su posle aktivisanja tripsin-versenom hemolizu pilećih eritrocita u razređenjima antigena 1:64 i 1:128 po ml uzorka i ispoljili intenzivnu hemaglutinacionu aktivnost od 512 i 1024HJ/0,1ml . Posle tretiranja navedenih uzoraka specifičnim hiperimunim serumom protiv virusa NDV čiji je titar bio 1:64, nije ustanovljena njihova hemolitička aktivnost. Rezultati pokazuju da postoji mogućnost korišćenja hemolitičkog testa za brzu detekciju imunološki značajnih glikoproteinskih antigena virusa NDV i njihovu identifikaciju sa specifičnim hiperimunim serumom.