E1A genes of adenovirus type 2 and type 5 are expressed at different levels.
Adenoviruses are an extensively studied system for modeling oncogenesis and for experimental cancer therapy. The most commonly analyzed virus types are 2 and 5, and little distinction has been made between them in past studies. Adenoviruses used for therapeutic purposes are frequently hybrids between these types, including the prototype dl1520/Onyx015. We tested the replication of the wild-type viruses WtD (a hybrid of the type 2 E1 region and type 5) and dl309 (type 5) in comparison with the mutants dl1520 (hybrid) and dl338 (type 5), the latter two lacking part of the E1B-55 kDa coding region. We found that the hybrid viruses replicated with considerably lower efficiency than their type 5 counterparts in H1299 cells (dl309:WtD = 3-4, dl338:dl1520 > 10). Moreover, adenovirus type 2 E1A expression from the hybrid viruses was strongly reduced in comparison to adenovirus type 5 E1A, as revealed by immunoblot analysis and RT-PCR, providing a potential explanation for the differences in virus yield. Differential E1A expression levels need to be taken into account for the construction of effective therapeutic viruses and when studying viral transformation.
Möritz
C
C
Institut für Virologie, Klinikum der Philipps-Universität Marburg, Marburg, Germany.
Dobbelstein
M
M
D000256:Adenoviridae / Q000235:genetics / Q000502:physiology*; D017500:Adenovirus E1A Proteins / Q000096:biosynthesis / Q000235:genetics*; D045744:Cell Line, Tumor; D015870:Gene Expression; D005822:Genetic Vectors; D006801:Humans; D015151:Immunoblotting; D012333:RNA, Messenger / Q000032:analysis; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014779:Virus Replication
D017500:Adenovirus E1A Proteins; D012333:RNA, Messenger; D012367:RNA, Viral