Gamma interferon (IFN-γ) plays an important role as a host defense in rickettsial infection. Swiss Webster mice, which are resistant to Rickettsia conorii (Malish 7 strain) infection, were treated with a monoclonal antibody against mouse IFN-γ. When the antibody-treated mice were inoculated with 12 50% tissue culture infective doses of R. conorii, the mortality was 47% and the morbidity was 100%. None of the control mice, which received the same dose of R. conorii, died or became ill. The enumeration of rickettsiae in organs by direct immunofluorescence in paraffin sections demonstrated higher quantities of rickettsiae in the spleen and liver of IFN-γ-depleted mice as compared with those of the infected controls. The kinetic analysis of IFN-γ levels in sera showed depletion in the treated mice. These results indicate that IFN-γ plays an important role as a host defense in the early stage of rickettsial infection. Survival of some mice despite continued treatment with antibody to IFN-γ suggests that other immune mechanisms may also be important.
|Original language||English (US)|
|Number of pages||4|
|Journal||Infection and immunity|
|State||Published - Jan 1 1987|
ASJC Scopus subject areas
- Infectious Diseases