Protective effect of interferon-γ on Chlamydia psittaci acute infection / 中国人兽共患病学报

ABSTRACT

We investigated the effects of IFN-γ on Chlamydia psittaci (Cps) infection.HeLa cells were treated with different concentrations of recombinant human IFN-γ (5 ng/mL,25 ng/mL,50 ng/mL) after infecting with C.psittaci 6BC,then the number and morphology of C.psittaci inclusion bodies were examined after 48 hours.C57BL/6J mice were intranasally infected with 2 × 106 IFUs C.psittaci 6BC,and intraperitoneally administrated with 10 μg recombinant murine interferon-γ 24 hours prior or post infection,then body weight,activity and survival rate were recorded.The histopathology of mice livers and lungs was analyzed by HE staining on day 5 or day10 post infection.And the chlamydial inclusion bodies were titrated in the lung homogenates of mice sacrificed on day 5 after infection.The inclusion body numbers of recombinant human IFN-γ treated groups (by 5ng/mL,25ng/mL,50ng/mL) were significantly less than that in the control group (23.8±5.1)× 106,(10± 3.58) × 106,(8.0±2.22) × 106,(43.3±11.05)× 106,respectively).And the morphology of inclusion bodies in IFN-γ treated HeLa cells was irregular and much smaller.We also found that IFN-γ could significantly improve the survival rate,reduce acute clinical manifestations and pathological injurery of lung and liver in C.psittaci respiratory tract infected mice model.So we summarized that IFN-γ can mediate strong immunological protection during acute C.psittaci early infection.