The Immunogenomic Landscape of Peripheral High-Dose IL-2 Pharmacodynamics in Patients with Metastatic Renal Cell Carcinoma: A Benchmark for Next-Generation IL-2-Based Immunotherapies.

High-dose (HD) IL-2 was the first immuno-oncology agent approved for treating advanced renal cell carcinoma and metastatic melanoma, but its use was limited because of substantial toxicities. Multiple next-generation IL-2 agents are being developed to improve tolerability. However, a knowledge gap still exists for the genomic markers that define the target pharmacology for HD IL-2 itself. In this retrospective observational study, we collected PBMC samples from 23 patients with metastatic renal cell carcinoma who were treated with HD IL-2 between 2009 and 2015. We previously reported the results of flow cytometry analyses. In this study, we report the results of our RNA-sequencing immunogenomic survey, which was performed on bulk PBMC samples from immediately before (day 1), during (day 3), and after treatment (day 5) in cycle 1 and/or cycle 2 of the first course of HD IL-2. As part of a detailed analysis of immunogenomic response to HD IL-2 treatment, we analyzed the changes in individual genes and immune gene signatures. By day 3, most lymphoid cell types had transiently decreased, whereas myeloid transcripts increased. Although most genes and/or signatures generally returned to pretreatment expression levels by day 5, certain ones representative of B cell, NK cell, and T cell proliferation and effector functions continued to increase, along with B cell (but not T cell) oligoclonal expansion. Regulatory T cells progressively expanded during and after treatment. They showed strong negative correlation with myeloid effector cells. This detailed RNA-sequencing immunogenomic survey of IL-2 pharmacology complements results of prior flow cytometry analyses. These data provide valuable pharmacological context for assessing PBMC gene expression data from patients dosed with IL-2-related compounds that are currently in development.

Gradients in the liver's extracellular matrix chemistry from periportal to pericentral zones: influence on human hepatic progenitors.

Embryonic mesenchymal feeders produce paracrine signals requisite for ex vivo survival and expansion of hepatic progenitors. The signals consist of a subset of soluble factors found in conditioned medium, and a subset of insoluble factors found in extracellular matrix that include collagens and basal adhesion molecules. We have identified key matrix components required for ex vivo maintenance of human hepatic progenitors produced by biologically active feeders. These components are similar to those found in zone 1 of the liver acinus (e.g., space of Disse) between layers of parenchyma and endothelia. Within these layers are transition chemistry matrix gradients, from zone 1 to zone 3. Use of purified zone 1 matrix components enables attachment and expansion of human hepatic progenitors independent of feeders. Cells aggregated into spheroid-like structures on laminin or spread into monolayers on type III or IV collagens. Contrastingly, a zone 3 matrix component, type I collagen, elicited growth arrest and differentiation. Another zone 3 matrix component, fibronectin, inhibited attachment. Use of specific matrix components, along with soluble paracrine signals from feeders, should enable one to maintain hepatic progenitors ex vivo without feeders and under wholly defined conditions.