Pathological and immunohistochemical evaluation of skin and teat papillomas in cattle


Abstract: Bovine skin and teat papillomas were examined for immunohistochemical expression of bovine papillomavirus (BPV), proliferating antigens (PCNA, Ki-67), CD3+ T lymphocytes, and some of the type III intermediate filaments. Papillomas showed epidermal hyperplasia, koilocytes, and hyperkeratosis with prominent dermal connective tissue. Immunohistochemistry found the presence of BPV antigens in the nuclei of granulosa cells. PCNA and Ki-67 revealed positive nuclear staining in the dermis and epidermis. Perivascular cuffing in the dermis predominantly consisted of CD3+ T cells. Immunoreaction to vimentin was strong in the connective tissue of the dermis. $\alpha$SMA positivity was mainly in the media of vessels. Smooth muscle cells of the dermal blood vessels showed an immunopositive reaction for desmin. Dermal connective tissue and squamous epithelia were negative for S-100 protein. This work revealed that BPV proliferates predominantly in the stratum granulosum cells and that in the regression of warts cell-mediated immune response has a key role. Vimentin was a very useful marker to show the contribution of fibrotic response to viral replication.

Keywords: Bovine papillomavirus, cattle, immunohistochemistry, papilloma, type III intermediate filaments

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