NF-kappa B signaling in myeloid cells mediates the pathogenesis of immune mediated nephritis
JOURNAL OF AUTOIMMUNITY
Authors: Chalmers, Samantha A.; Garcia, Sayra J.; Reynolds, Joshua A.; Herlitz, Leal; Putterman, Chaim
Abstract
Immune-mediated glomerulonephritis is a serious end organ pathology that commonly affects patients with systemic lupus erythematosus (SLE). A classic murine model used to study lupus nephritis (LN) is nephrotoxic serum nephritis (NTN), in which mice are passively transferred nephrotoxic antibodies. We have previously shown that macrophages are important in the pathogenesis of LN. To further investigate the mechanism by which macrophages contribute to the pathogenic process, and to determine if this contribution is mediated by NF-kappa B signaling, we created B6 mice which had ReIA knocked out in myeloid cells, thus inhibiting classical NF-kappa B signaling in this cell lineage. We induced NTN in this strain to assess the importance of macrophage derived NF-kappa B signaling in contributing to disease progression. Myeloid cell RelA knock out (KO) mice injected with nephrotoxic serum had significantly attenuated proteinuria, lower BUN levels, and improved renal histopathology compared to control injected wildtype B6 mice (WT). Inhibiting myeloid NF-kappa B signaling also decreased inflammatory modulators within the kidneys. We found significant decreases of IL-la, IFNg, and IL-6 in kidneys from KO mice, but higher IL-10 expression. Flow cytometry revealed decreased numbers of kidney infiltrating classically activated macrophages in KO mice as well. Our results indicate that macrophage NF-kappa B signaling is instrumental in the contribution of this cell type to the pathogenesis of NTN. While approaches which decrease macrophage numbers can be effective in immune mediated nephritis, more targeted treatments directed at modulating macrophage signaling and/or function could be beneficial, at least in the early stages of disease.
Indoleamine 2,3-Dioxygenase Expression Pattern in the Tumor Microenvironment Predicts Clinical Outcome in Early Stage Cervical Cancer
FRONTIERS IN IMMUNOLOGY
Authors: Heeren, A. Marijne; van Dijk, Ilse; Berry, Daniella R. A. I.; Khelil, Maryam; Ferns, Debbie; Kole, Jeroen; Musters, Rene J. P.; Thijssen, Victor L.; Mom, Constantijne H.; Kenter, Gemma G.; Bleeker, Maaike C. G.; de Gruijl, Tanja D.; Jordanova, Ekaterina S.
Abstract
The indoleamine 2,3-dioxygenase (IDO) enzyme can act as an immunoregulator by inhibiting T cell function via the degradation of the essential amino acid tryptophan (trp) into kynurenine (kyn) and its derivates. The kyn/trp ratio in serum is a prognostic factor for cervical cancer patients; however, information about the relationship between serum levels and IDO expression in the tumor is lacking. IDO expression was studied in 71 primary and 14 paired metastatic cervical cancer samples by various immunohistochemical (IHC) techniques, including 7-color fluorescent multiparameter IHC, and the link between the concentration of IDO metabolites in serum, clinicopathological characteristics, and the presence of (proliferating) T cells (CD8, Ki67, and FoxP3) was examined. In addition, we compared the relationships between IDO1 and IFNG gene expression and clinical parameters using RNAseq data from 144 cervical tumor samples published by The Cancer Genome Atlas (TCGA). Here, we demonstrate that patchy tumor IDO expression is associated with an increased systemic kyn/trp ratio in cervical cancer (P = 0.009), whereas marginal tumor expression at the interface with the stroma is linked to improved disease-free (DFS) (P = 0.017) and disease-specific survival (P = 0.043). The latter may be related to T cell infiltration and localized IFN. release inducing IDO expression. Indeed, TCGA analysis of 144 cervical tumor samples revealed a strong and positive correlation between IDO1 and IFNG mRNA expression levels (P < 0.001) and a significant association with improved DFS for high IDO1 and IFNG transcript levels (P = 0.031). Unexpectedly, IDO+ tumors had higher CD8+ Ki67+ T cell rates (P = 0.004). Our data thus indicate that the serum kyn/trp ratio and IDO expression in primary tumor samples are not clear-cut biomarkers for prognosis and stratification of patients with early stage cervical cancer for clinical trials implementing IDO inhibitors. Rather, a marginal IDO expression pattern in the tumor dominantly predicts favorable outcome, which might be related to IFN. release in the cervical tumor microenvironment.