Subpopulations of lymphocytes in cattle naturally infected with papillomavirus.

Subpopulations of blood lymphocytes (CD2, CD4, CD8, WC1 and IgM-mu chain) were evaluated in clinically manifested bovine papillomatosis. Significantly lower numbers of CD2 (44.7%), CD4 (22.8%) and a lower ratio of CD4/CD8 (1.5) were found in animals with tumours compared to a group of cattle free of papillomas (62.3%, 34%, and 2.3, respectively). On the other hand, significantly higher numbers of gamma/delta+ T lymphocytes (9.6%) and of lymphocytes expressing IgM molecules (35%) were observed in the group of tumour-bearing cattle than in the papilloma-free group (4.8% and 22.1%, respectively). The animals came from a region characterised by elevated concentrations of copper, zinc, arsenic, cadmium and lead in the soil and in the organs of animals. It is supposed that environmental factors predisposed the animals to the development of papillomas.