Project description:Engineered cytokine-based approaches for immunotherapy of cancer are poised to enter the clinic, with IL-12 being at the forefront. However, little is known about potential mechanisms of resistance to cytokine therapies. We found that orthotopic murine lung tumors were resistant to systemically delivered IL-12 fused to murine serum albumin (MSA, IL12-MSA) due to low IL-12R expression on tumor-reactive CD8+ T cells. IL2-MSA increased binding of IL12-MSA by tumor-reactive CD8+ T cells, and combined administration of IL12-MSA and IL2-MSA led to enhanced tumor-reactive CD8+ T cell effector differentiation, decreased numbers of tumor-infiltrating CD4+ regulatory T (Treg) cells, and increased survival of lung tumor-bearing mice. Predictably, the combination of IL-2 and IL-12 at therapeutic doses led to significant dose-limiting toxicity. Administering IL-12 and IL-2 analogs with preferential binding to cells expressing IL12rb1 and CD25, respectively, led to a significant extension of survival in mice with lung tumors while abrogating dose-limiting toxicity. These findings suggest that IL-12 and IL-2 represent a rational approach to combination cytokine therapy whose dose-limiting toxicity can be overcome with engineered cytokine variants.
Project description:RNA was extracted from each brain of 3 wild-type and 3 MSA Transgenic mice at the age of 16 weeks and microarray analysis was performed on each sample.
Project description:Our transcriptomic data shows that iron impact on human osteoblastic MG-63 cells by decreasing HHIPL-2 gene expression (2 fold ratio). This impact is corrected in presence of deferoxamine. Additional biological experiments in the manuscript suggest that the iron related modulation of HHIPL-2 gene expression could take place in the decrease of osteoblastic markers in the MG-63 cell line. Such mechanisms could participate to the development of osteoporosis in iron overloaded patients.
Project description:Mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig small intestinal segment perfusion (SISP) model. L. plantarum 299v wildtype strain was compared to two isogenic mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). Salmonella typhimurium served as a positive control for gene expression analysis. Scrapings from jejunal segments were collected after perfusion with bacterial suspensions or PBS (control) for 4 or 8 hours, and host gene expression was assessed using a home-made cDNA porcine microarray. Keywords: host-microbe interaction, Lactobacillus plantarum, mannose-specific adhesion
Project description:Time-series transcriptional profiles of Shewanella oneidensis type strain MR-1 under iron depletion and repletion conditions. Iron homeostasis of Shewanella oneidensis, a gamma-proteobacterium possessing high iron content, is regulated by a global transcription factor Fur. However, knowledge is incomplete about other biological pathways that respond to changes in iron concentration, as well as details of the responses. In this work, temporal gene expression profiles were examined for iron depletion and repletion to delineate the iron response of S. oneidensis and a gene co-expression network was reconstructed. Modules of iron acquisition systems, anaerobic energy metabolism and protein degradation were the most noteworthy in the gene network. Bioinformatics analyses suggested that genes in each of the modules might be regulated by DNA-binding proteins Fur, CRP and RpoH, respectively. Closer inspection of these modules revealed a transcriptional regulator (SO2426) involved in iron acquisition and ten transcriptional factors involved in anaerobic energy metabolism. Selected genes in the network were analyzed by genetic studies. Disruption of genes encoding a putative alcaligin biosynthesis protein (SO3032) and a gene previously implicated in protein degradation (SO2017) led to severe growth deficiency under iron depletion conditions. Disruption of a novel transcriptional factor (SO1415) caused deficiency in both anaerobic iron reduction and growth with thiosulfate or TMAO as an electronic acceptor, suggesting that SO1415 is required for specific branches of anaerobic energy metabolism pathways. In conclusion, we identified major biological pathways that were differentially expressed during iron depletion and repletion.