A novel way to assess murine delayed type hypersensitivity: Elicitation of response in the tail

Mice were sensitized with sheep red blood cells (SRBC) and challenged 3–7 days later with a mid tail subcutaneous injection of SRBC. Delayed type hypersensitivity (DTH) was assessed by the amount of tail swelling elicited by antigen challenge and was reflected in a histological pattern of an accumulation of lymphocytes and monocytes-macrophages. The swelling response was specific to the antigen used. The amount of swelling was dependent on the numbers of SRBC used during both sensitization and challenge. The route of administration for sensitization had a variable effect on the DTH response and had significant effects on the amount of hemagglutinating antibody to SRBC. This method of assessing delayed type hypersensitivity in the mouse is rapid, reproducible, and can be done by one individual. We have found the measurement of tail swelling to be a convenient alternative to measuring tissue swelling in a footpad or ear.