title: Cottontail rabbit papillomavirus in Langerhans cells in Sylvilagus spp.
abstract: A wildlife sanctuary presented an adult female cottontail rabbit (Sylvilagus spp.), age unknown, to the Colorado State University Pathology service for postmortem examination. Gross examination revealed numerous pigmented wartlike lesions arising from the skin of the head surrounding the ears, eyes, nares, mouth, and dorsum. Masses were firm, friable, and easily detached from the underlying skin. Differential diagnoses included Cottontail rabbit papillomavirus, Rabbit fibroma virus, and Myxoma virus. Histological examination revealed multiple papillary masses lined by stratified squamous epithelial cells with central cores of fibrovascular connective tissue and parakeratotic hyperkeratosis. Cells of the Stratum spinosum were frequently swollen with abundant perinuclear, cytoplasmic, clearing, and occasional intranuclear basophilic, glassy, spherical inclusions up to 3 microm in diameter. The lesions were consistent with Cottontail rabbit papillomavirus infection. Papilloma virus antigens were identified by immunohistochemistry. In addition, papillomavirus particles were identified by transmission electron microscopy within Langerhans cells of the epidermis, suggesting a unique mechanism for systemic dissemination of the virus. The present case report highlights the finding of viral particles within the Langerhans cells and suggests a novel mechanism of pathogenesis.
authors.affiliation: Department of Microbiology, Immunology & Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, 1619 Campus Delivery, Fort Collins, CO 80523, USA. Cristina.Weiner@research.colostate.edu
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Weiner
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Rosenbaum
authors.forename: Karen
authors.initials: K
authors.lastname: Fox
authors.forename: Gary
authors.initials: G
authors.lastname: Mason
authors.forename: Helle
authors.initials: H
authors.lastname: Bielefeldt-Ohmann
authors.forename: D N Rao
authors.initials: DN
authors.lastname: Veeramachaneni
authors.forename: Sue
authors.initials: S
authors.lastname: Vandewoude
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000821:virology; D012777:Cottontail rabbit papillomavirus / Q000302:isolation & purification*; D005260:Female; D006197:Hair / Q000473:pathology / Q000821:virology; D007150:Immunohistochemistry; D007801:Langerhans Cells / Q000473:pathology / Q000821:virology*; D030361:Papillomavirus Infections / Q000473:pathology / Q000662:veterinary*; D011817:Rabbits; D012867:Skin / Q000473:pathology / Q000821:virology