Cell-extrinsic effects of tumor ER stress imprint myeloid dendritic cells and impair CD8⁺ T cell priming.

Tumor-infiltrating myeloid cells, such as dendritic cells (BMDC), are key regulators of tumor growth. However, the tumor-derived signals polarizing BMDC to a phenotype that subverts cell-mediated anti-tumor immunity have yet to be fully elucidated. Addressing this unresolved problem we show that the tumor unfolded protein response (UPR) can function in a cell-extrinsic manner via the transmission of ER stress (TERS) to BMDC.

Innate immune induction and influenza protection elicited by a response-selective agonist of human C5a.

The anaphylatoxin C5a is an especially potent mediator of both local and systemic inflammation. However, C5a also plays an essential role in mucosal host defense against bacterial, viral, and fungal infection. We have developed a response-selective agonist of human C5a, termed EP67, which retains the immunoenhancing activity of C5a at the expense of its inflammatory, anaphylagenic properties.

Transmission of endoplasmic reticulum stress and pro-inflammation from tumor cells to myeloid cells.

Metabolic, infectious, and tumor cell-intrinsic noxae can all evoke the endoplasmic reticulum (ER) stress response in tumor cells, which is critical for tumor cell growth and cancer progression. Evidence exists that the ER stress response can drive a proinflammatory program in tumor cells and macrophages but, to our knowledge, a role for the tumor ER stress response in influencing macrophages and inflammation in the tumor microenvironment has not been suggested. Here we show that macrophages cultured in conditioned medium from ER-stressed tumor cells become activated, and themselves undergo ER stress with the up-regulation of Grp78, Gadd34, Chop, and Xbp-1 splicing, suggesting a general activation of the ER stress-signaling pathways.

A cleavage enzyme-cytometric bead array provides biochemical profiling of resistance mutations in HIV-1 Gag and protease.

Most protease-substrate assays rely on short, synthetic peptide substrates consisting of native or modified cleavage sequences. These assays are inadequate for interrogating the contribution of native substrate structure distal to a cleavage site that influences enzymatic cleavage or for inhibitor screening of native substrates. Recent evidence from HIV-1 isolates obtained from individuals resistant to protease inhibitors has demonstrated that mutations distal to or surrounding the protease cleavage sites in the Gag substrate contribute to inhibitor resistance.

Bead-based multianalyte flow immunoassays: the cytometric bead array system.

Analytical cytometry has significant potential beyond cellular analysis. The inherent capability of flow cytometers to efficiently discriminate between uniformly sized particles based on their intrinsic properties provides the foundation for multiplex bead assays. The technology can be exploited in designing immunoassays, Western blot-like antibody assays, and nucleic acid hybridization assays.

Upregulation of PD-1 expression on HIV-specific CD8+ T cells leads to reversible immune dysfunction.

The engagement of programmed death 1 (PD-1) to its ligands, PD-L1 and PD-L2, inhibits proliferation and cytokine production mediated by antibodies to CD3 (refs. 5,6,7). Blocking the PD-1-PD-L1 pathway in mice chronically infected with lymphocytic choriomeningitis virus restores the capacity of exhausted CD8(+) T cells to undergo proliferation, cytokine production and cytotoxic activity and, consequently, results in reduced viral load.

Cytometric bead array: a multiplexed assay platform with applications in various areas of biology.

The introduction of flow cytometric bead-based technology has added a new approach for investigators to simultaneously measure multiple analytes in biological and environmental samples. This new technology allows for (1) evaluation of multiple analytes in a single sample; (2) utilization of minimal sample volumes to glean data; (3) reproducibility and results comparative with previous experiments; (4) direct comparison with existing assays; and (5) a more rapid evaluation of multiple samples in a single platform. The cytometric bead array (CBA) system enables simultaneous measurement of multiple analytes in sample volumes too small for traditional immunoassays.