Regulation immunosuppression

SP4: Regulation of immune suppression through CD163 in pyelonephritis and chronic lymphocytic leukemia

Pyelonephritis (PN) is a condition defined by bacterial invasion of the renal parenchyma. While most patients exhibit a mild course of the disease, a fraction of elderly, immunodeficient and cancer patients develops severe PN, requiring hospitalization. However, the mechanisms, which cause increased susceptibility to bacterial infections, leading to severe inflammation and impairment of kidney function are not understood. Innate immune cells, such as macrophages, employ a very broad phenotypical and functional repertoire and modulate critical anti-bacterial immune responses. The hemoglobin (Hb) scavenger receptor CD163 plays an essential role in macrophages polarization towards an anti-inflammatory state and has been implicated in different types of cancer and immunological disorders. Preliminary data revealed a highly significant upregulation of CD163 in the kidney of human patients suffering from severe PN. Through this proposal, we aim to study whether the expression of CD163 on macrophages predispose to severe PN through immunosuppression. The aims are to deconvolute the spatial proteome to study macrophage polarization in human PN, to clarify the spatial mechanism for macrophage polarization in human PN, to evaluate the potential of soluble CD163 as a biomarker in blood and urine of PN patients, to investigate the mechanism of immune suppression in chronic lymphocytic leukemia (CLL) through CD163+ macrophages, and to clarify the role of CD163+ macrophages in PN.