The immune system of the ferret ( Mustela putorius furo ) - A review

The basic information dealing with the anatomy of the ferret's immune system, cross-reactivity of the ferret leukocytes with polyclonal and monoclonal antibodies and immune response to the mitogens and various infections are presented. The leukocyte numbers in the peripheral blood in the ferrets are lower compared to other species and only one subclass of IgG has been identified in ferrets so far. Lymphocytes make up 12-67% of all the leukocytes in the peripheral blood of the healthy adult ferrets. Lymphocyte subpopulations are similar to other mammals and include T- and B-lymphocytes. T-lymphocytes differentiate into helper (Th) lymphocytes and cytotoxic (Tc) lymphocytes. Currently, ferret granulocytes (CD11), B-lymphocytes (CD79α), T-lymphocytes (CD3), Th-lymphocytes (CD3, CD4), Tc-lymphocytes (CD3, CD8), and CD30, CD45 subpopulations are detected with the use of a number of polyclonal as well as with monoclonal antibodies. In a lymphocyte transformation assay, the mitogen response of the peripheral blood mononuclear cells to concanavalin A (ConA), phytohaemagglutinin (PHA), and pokeweed mitogen (PWM) is the greatest at day 2, 2 and 3, respectively. Serious lymphopenia is observed in ferrets during a distemper infection. A significant decrease in the lymphocyte transformation activity is observed on day 5 and reaches a maximal decrease on days 8-11, with full recovery on days 23-30 after the inoculation of laboratory ferrets with the distemper virus. Ferrets have also been used in studies related to the function of the immune system in infections, Crohn's disease and bronchial asthma.