Research article

Genomic and bioinformatics analysis of human adenovirus type 37: New insights into corneal tropism

Christopher M Robinson^1,3 , Fatemeh Shariati^1,2 , Allison F Gillaspy^3,5 , David W Dyer^3,5 and James Chodosh^1,2,3,4

¹  Molecular Pathogenesis of Eye Infection Research Center, Dean A. McGee Eye Institute, 608 Stanton L. Young Blvd., Oklahoma City, OK 73104, USA

²  Department of Ophthalmology, University of Oklahoma Health Sciences Center, 1100 North Lindsay, Oklahoma City, OK 73104, USA

³  Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, 1100 North Lindsay, Oklahoma City, OK 73104, USA

⁴  Department of Cell Biology, University of Oklahoma Health Sciences Center, 1100 North Lindsay, Oklahoma City, OK 73104, USA

⁵  Laboratory for Genomics and Bioinformatics, University of Oklahoma Health Sciences Center, 1100 North Lindsay, Oklahoma City, OK 73104, USA

author email corresponding author email

BMC Genomics 2008, 9:213doi:10.1186/1471-2164-9-213

Published:	9 May 2008

Abstract

Background

Human adenovirus type 37 (HAdV-37) is a major etiologic agent of epidemic keratoconjunctivitis, a common and severe eye infection associated with long-term visual morbidity due to persistent corneal inflammation. While HAdV-37 has been known for over 20 years as an important cause, the complete genome sequence of this serotype has yet to be reported. A detailed bioinformatics analysis of the genome sequence of HAdV-37 is extremely important to understanding its unique pathogenicity in the eye.

Results

We sequenced and annotated the complete genome of HAdV-37, and performed genomic and bioinformatics comparisons with other HAdVs to identify differences that might underlie the unique corneal tropism of HAdV-37. Global pairwise genome alignment with HAdV-9, a human species D adenovirus not associated with corneal infection, revealed areas of non-conserved sequence principally in genes for the virus fiber (site of host cell binding), penton (host cell internalization signal), hexon (principal viral capsid structural protein), and E3 (site of several genes that mediate evasion of the host immune system). Phylogenetic analysis revealed close similarities between predicted proteins from HAdV-37 of species D and HAdVs from species B and E. However, virtual 2D gel analyses of predicted viral proteins uncovered unexpected differences in pI and/or size of specific proteins thought to be highly similar by phylogenetics.

Conclusion

This genomic and bioinformatics analysis of the HAdV-37 genome provides a valuable tool for understanding the corneal tropism of this clinically important virus. Although disparities between HAdV-37 and other HAdV within species D in genes encoding structural and host receptor-binding proteins were to some extent expected, differences in the E3 region suggest as yet unknown roles for this area of the genome. The whole genome comparisons and virtual 2D gel analyses reported herein suggest potent areas for future studies.