Bandicoots, Bonobos, and Boys: Papillomavirus and Vaccination Strategies

Abstract

To better understand strategies for elimination of human papillomavirus (HPV), a brief history may provide insight. Papillomaviruses certainly are much older than humankind. They are relatively simple viruses containing a short double-stranded DNA genome, surrounded by a protein capsid. A single viral protein called L1 is all that is required for the formation of the icosahedral capsid. Papillomaviruses multiply mainly in squamous epithelia of the skin and genital surfaces. The viruses enter through small breaks in the epithelial surface. The virus then produces progeny virus that exit the host as the epithelial cell desquamates. Papillomaviruses are present in many mammals. One dramatic example is the bandicoot, one of many ancient marsupial species found only in Australia (Fig 1). Two closely related primordial papillomaviruses have been isolated from bandicoots.1 The viruses may have arisen 10 million years ago when Australia was physically separated from all other continents on planet earth. They are killing many bandicoots by causing skin infiltrates consisting of extensive epidermal hyperplasia leading to papillomas and carcinomas on the mouth, face, and flanks. Both male and female bandicoots are afflicted. Papillomaviruses also coevolved over 6 million years ago with higher primates such as the bonobo of central Africa, previously called the pygmy chimpanzee. The bonobo has become well known for social and sexual characteristics that more closely resemble humankind than its common chimpanzee cousin. Bonobos develop oral focal epithelial hyperplasia and papillomas caused by a virus strain that closely resembles HPV.2 Both male and female bonobos are afflicted. Lucy and her Australopithicus family members, who lived in eastern Africa 3 million years ago, certainly were infected with papillomaviruses and passed them on to their descendents. As a … Address correspondence to Charles Grose, MD, University of Iowa, Department of Pediatrics, 200 Hawkins Dr, Iowa City, IA 52242. E-mail: charles-grose{at}uiowa.edu