The main adaptive immune cells are T and B lymphocytes and they play key roles in the induction of immune responses against canine mammary tumours. Investigating these cell subpopulations may lead to more precise diagnosis of these malignancies.

Bovine leukaemia virus (BLV) is a Deltaretrovirus responsible for enzootic bovine leukosis, the most common neoplastic disease of cattle. It deregulates the immune system, favouring secondary infections and changes in the blood and lymphatic tissues. Blood homeostasis depends on functional haematopoietic stem cells (HSCs). Bone marrow is populated by these cells, which express CD34+ and CD35+ surface antigens and produce and release cytokines involved in the maintenance of haematopoiesis. The aim of the study was determination of the profile of cytokine production by CD34+ stem cells of cattle naturally infected with BLV.