Replication of an adenovirus type 34 mutant DNA containing tandem reiterations of the inverted terminal repeat

The complete nucleotide sequence, genome organization, and origin of human adenovirus type 11

The complete DNA sequence and transcription map of human adenovirus type 11 are reported here. This is the first published sequence for a subgenera B human adenovirus and demonstrates a genome organization highly similar to those of other human adenoviruses. All of the genes from the early, intermediate, and late regions are present in the expected locations of the genome for a human adenovirus. The genome size is 34,794 bp in length and has a GC content of 48.9%. Sequence alignment with genomes of groups A (Ad12), C (Ad5), D (Ad17), E (Simian adenovirus 25), and F (Ad40) revealed homologies of 64, 54, 68, 75, and 52%, respectively. Detailed genomic analysis demonstrated that Ads 11 and 35 are highly conserved in all areas except the hexon hypervariable regions and fiber. Similarly, comparison of Ad11 with subgroup E SAV25 revealed poor homology between fibers but high homology in proteins encoded by all other areas of the genome. We propose an evolutionary model in which functional viruses can be reconstituted following fiber substitution from one serotype to another. According to this model either the Ad11 genome is a derivative of Ad35, from which the fiber was substituted with Ad7, or the Ad35 genome is the product of a fiber substitution from Ad21 into the Ad11 genome. This model also provides a possible explanation for the origin of group E Ads, which are evolutionarily derived from a group C fiber substitution into a group B genome.

The long repeat region is dispensable for fowl adenovirus replication in vitro

Two regions containing tandemly repeated sequences are present in the fowl adenovirus 9 (FAdV-9) genome. The longer repeat region (TR-2) is composed of 13 contiguous 135-bp-long direct repeats, the function of which is unknown. An infectious FAdV-9 genomic clone, constructed by homologous recombination in Escherichia coli, was used for engineering of recombinant viruses. The enhanced green fluorescence protein (EGFP) coding sequence was cloned in both rightward and leftward orientations so as to replace TR-2. Replication-competent recombinant FAdVs were recovered, demonstrating that TR-2 was dispensable for FAdV-9 propagation in vitro. The expression of EGFP in infected cells was demonstrated by fluorescence microscopy, immunoprecipitation, and RT-PCR.

Acute follicular conjunctivitis caused by adenovirus type 34

PURPOSE

Adenovirus type 34 belongs to adenovirus subgenus B. The prototype virus of adenovirus 34 was isolated from a renal transplant recipient. However, no case of acute conjunctivitis caused by adenovirus 34 has been reported. Recently, we encountered two cases of acute follicular conjunctivitis in which adenovirus 34 was isolated.

METHODS

The clinical isolates were identified by the standard neutralization test. The sequences of seven hypervariable regions in the hexon protein of these cases were compared with those of several prototype strains of adenovirus subgenus B.

RESULTS

The cases were middle-aged, 34 and 41 years old, and male, and they exhibited moderate conjunctivitis with upper respiratory tract symptoms. Isolates from cell culture were identified as adenovirus 34 by NT. The mean homology rate (percentage of total number of coincident amino acids in the total length of amino acids in seven hypervariable regions) between clinical isolates and the adenovirus 34 prototype was 96.5%; in contrast, those between clinical isolates and the prototypes of adenovirus 11, adenovirus 14, and adenovirus 35 were 55.6%, 66.7%, and 57.9%, respectively. The results of conventional serotyping by neutralization test were confirmed by these values.

CONCLUSIONS

These results indicate that adenovirus 34 may induce acute conjunctivitis in immunocompetent subjects and that special attention should be paid to adenovirus 34 as a causative agent for adenoviral conjunctivitis.

Human adenovirus early region 4 open reading frame 1 genes encode growth-transforming proteins that may be distantly related to dUTP pyrophosphatase enzymes

An essential oncogenic determinant of subgroup D human adenovirus type 9 (Ad9), which uniquely elicits estrogen-dependent mammary tumors in rats, is encoded by early region 4 open reading frame 1 (E4 ORF1). Whereas Ad9 E4 ORF1 efficiently induces transformed foci on the established rat embryo fibroblast cell line CREF, the related subgroup A Ad12 and subgroup C Ad5 E4 ORF1s do not (R. T. Javier, J. Virol. 68:3917-3924, 1994). In this study, we found that the lack of transforming activity associated with non-subgroup D adenovirus E4 ORF1s in CREF cells correlated with significantly reduced protein levels compared to Ad9 E4 ORF1 in these cells. In the human cell line TE85, however, the non-subgroup D adenovirus E4 ORF1s produced protein levels higher than those seen in CREF cells as well as transforming activities similar to that of Ad9 E4 ORF1, suggesting that all adenovirus E4 ORF1 polypeptides possess comparable cellular growth-transforming activities. In addition, searches for known proteins related to these novel viral transforming proteins revealed that the E4 ORF1 proteins had weak sequence similarity, over the entire length of the E4 ORF1 polypeptides, with a variety of organismal and viral dUTP pyrophosphatase (dUTPase) enzymes. Even though adenovirus E4 ORF1 proteins lacked conserved protein motifs of dUTPase enzymes or detectable enzymatic activity, E4 ORF1 and dUTPase proteins were predicted to possess strikingly similar secondary structure arrangements. It was also established that an avian adenovirus protein, encoded within a genomic location analogous to that of the human adenovirus E4 ORF1s, was a genuine dUTPase enzyme. Although no functional similarity was found for the E4 ORF1 and dUTPase proteins, we propose that human adenovirus E4 ORF1 genes have evolved from an ancestral adenovirus dUTPase and, from this structural framework, developed novel transforming properties.