Induction of delayed-type hypersensitivity to measles virus in mice.

Intracutaneous injection of inactivated measles virus (MV) into hind footpads of BALB/c mice infected 5 to 11 days previously with MV produces a strong delayed-type hypersensitivity (DTH) response. Pretreatment of mice with cyclophosphamide (CP) results in a significantly stronger response. In CP-pretreated mice, the optimal infecting dose of live MV and the restimulating amount of inactivated MV are approximately 10(7) plaque-forming units and 2 micrograms/mouse, respectively. The optimal time after infection for measuring DTH to MV is 7 days, while the optimal CP-pretreatment concentration is 200 mg/kg. The DTH response generated by MV is specific and not caused by fetal calf serum or Vero cell antigens. MV DTH is transferable to uninfected mice with lymph node cells. Transfer of DTH is sensitive to treatment with anti-Thy 1.2 serum plus complement, indicating the response is T cell dependent. With this sensitive assay for measuring cell-mediated immunity to MV, it will now be possible to analyze T cell cross-reactivity among paramyxoviruses and assess viral cell-mediated immunity in mice infected with neuroadapted MV.