&nBsp;Pneumocystispneumonia(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 howcorticosteroidsalter the host defense against Pneumocystis infection. In the present study, we usedtranscriptomeanalysisto examine theimmuneresponse 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 Bcellsin 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