Papilloma-Myxoma Viruses

Immunological Aspects of Wart Regression With Special Reference to Regression Phenomenon of Numerous Flat Warts

“…Another counterpart is EV, the generalized infection of HPV3 and HPV5 characterized by numerous, life-long, flat wart-like lesions which show a high rate of malignant transformation. Like the human counterpart, in genetically prone animals, papillomas persist for years before they eventually give rise to malignant lesions (51).…”

Multiple copies of Shope virus DNA are present in cells of benign and malignant non-virus-producing neoplasms

“…In Eastern cottontail rabbits (Sylvalagus floridanus) the Shope papilloma virus induces virus-producing papillomas and, in some instances, carcinomas (non-virus-producing) appear at the same site several months later. A similar two-stage course of events occurs in domestic rabbits (Oryctalagus cuniculus), but in these animals, neither tumor characteristically produces virus, and a greater proportion of papillomas become malignant (11,18). Although the agent is not present in the latter tumors (or present at very low levels in some instances), viral genetic information is conserved, since DNA extracted from either induces the same papilloma-carcinoma sequence when introduced into the skin of other domestic rabbits (9, 10,11).…”

“…A similar two-stage course of events occurs in domestic rabbits (Oryctalagus cuniculus), but in these animals, neither tumor characteristically produces virus, and a greater proportion of papillomas become malignant (11,18). Although the agent is not present in the latter tumors (or present at very low levels in some instances), viral genetic information is conserved, since DNA extracted from either induces the same papilloma-carcinoma sequence when introduced into the skin of other domestic rabbits (9, 10,11). In addition, it has been reported that virusspecific antigens are detectable in cells of papillomas and in tissue cultures derived from them (15,17,20).…”