&nBsp;       Pneumocystis pneumonia (PCP) is an opportunistic infectious disease that is prevalent in immunosuppressed hosts. Corticosteroid treatment is the most significant risk factor for HIV-negative patients with PCP, although little is known about how corticosteroids alter the host defense against Pneumocystis infection. In the present study, we used transcriptome analysis to examine the immune response in the lungs of corticosteroid-treated PCP mice. The results showed downregulation in the genes related to both native immunity, such as antigen processing and presentation,inflammatory response, and phagocytosis, as well as B and T lymphocyte immunity.The repression of gene expression, corresponding to B cell immunity including B cell signaling, homeostasis and immunoglobulin production, was prominent. The finding was confirmed by qPCR of mice lungs and the peripheral blood of PCP patients. Flow cytometry also revealed a significant depletion of B cells in corticosteroid-treated PCP mice. Our study has highlighted that corticosteroid treatment suppresses the B cell immunity in the PCP host, which is likely to be one of the main reasons that corticosteroid treatment may stimulate PCP development.

閱讀全文請見：Transcriptomic Analysis Reveals Significant B Lymphocyte Suppression in Corticosteroid-treated Hosts with Pneumocystis Pneumonia