Transcriptome Analysis of the Impact of Dexamethasone on the Immune Response in Mice with Pneumocystis Infection. Mus musculus

Pneumocystis pneumonia (PCP) is an opportunistic infectious disease prevalent in immunosuppressive host. Corticosteroids treatment is the most significant risk factor for HIV-negative patients with PCP, though little is known about how corticosteroids alters the host defense against Pneumocystis infection. In the present study, we used transcriptomic analysis to examine the immune response in the lung of dexamethasone-treated PCP mice and compare the immune reaction of them with those without dexamethasone treatment. Overall design: Healthy 4-5 week old male C57BL/6 mice were randomly assigned to 3 groups: wild-type PCP mice, dexamethasone-treated PCP mice and wild-type mice without infection (control). Then dexamethasone-treated PCP mice were given 4mg/l dexamethasone and 1 mg/ml tetracycline in drinking water consecutively from 14 days prior to Pneumocystis infection to euthanasia. Both dexamethasone-treated and wild-type PCP mice were inoculated intratracheally with 1 × 10^6 Pneumocystis nuclei and control mice were given lung homogenate from uninfected scid mice.Fourteen days after infection, mice were sacrificed and the left lung was excised. Affymetrix microarrays were performed in the lung of 5 dexamethasone-treated PCP mice, 5 wild-type PCP mice and 4 control mice.