Biology subjects

Donelan, W.

Publications and source records attributed to Donelan, W..

3 recordsLinked to original sources

bioRxiv2020

Detection of PD-L1-expressing myeloid cell clusters in the hyaluronan-enriched stroma in tumor tissue and tumor-draining lymph nodes

Expression of the transmembrane protein PD-L1 is frequently up-regulated in cancer. Since PD-L1-expressing cells can induce apoptosis or anergy of T lymphocytes through binding to PD1 receptor, the PD-L1-mediated inhibition of activated PD1+ T cells considered as a major pathway for tumor immune escape. However, the mechanisms that regulate the expression of PD-L1 in the tumor microenvironment not fully understood. Analysis of organotypic tumor tissue slice cultures, obtained from tumor-bearing mice as well as from cancer patients, revealed that tumor-associated hyaluronan (HA) supports the development of the immunosuppressive PD-L1+ macrophages. Using genetically modified tumor cells, we identified both epithelial tumor cells and cancer-associated fibroblasts (CAFs) as the major source of HA in the tumor microenvironment. HA-producing tumor cells and, in particular CAFs of bone marrow origin, directly interact with tumor-recruited Hyal2+ myeloid cells forming the large stromal congregates/clusters that are highly enriched for both HA and PD-L1. Furthermore, similar cell clusters comprising of HA-producing fibroblasts and PD-L1+ macrophages were detected in the tumor-draining lymph nodes. Collectively, our findings indicate that the formation of multiple large HA-enriched stromal clusters that support the development of PD-L1-expressing antigen-presenting cells in the tumor microenvironment and draining lymph nodes could contribute to the immune escape and resistance to immunotherapy in cancer.

cancer biology↗

bioRxiv2020

Identification of Hyal2-expressing tumor-associated myeloid cells in cancer: implications for cancer-related inflammation through enhanced hyaluronan degradation

Increased presence of myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) in tumor tissue has been extensively reported. These cells represent a major constituent of tumor infiltrate and exhibit a distinct phenotype with immunosuppressive and tolerogenic functions. However, their role in the regulation of hyaluronan (HA) metabolism in the tumor microenvironment has not been established. Here we describe a novel function of tumor-associated myeloid cells related to the enhanced breakdown of extracellular HA in human bladder cancer tissue leading to accumulation of small HA fragments with MW <20 kDa. Increased fragmentation of extracellular HA and accumulation of low molecular weight HA (LMW-HA) in tumor tissue was associated with elevated production of multiple inflammatory cytokines, chemokines, and angiogenic factors. The fragmentation of HA by myeloid cells was mediated by the membrane-bound enzyme hyaluronidase 2 (Hyal2). The increased numbers of Hyal2+CD11b+ myeloid cells were detected in the tumor tissue as well as in the peripheral blood of bladder cancer patients. Co-expression of CD33 suggests that these cells belong to monocytic myeloid-derived suppressor cells. HA-degrading function of Hyal2-expressing MDSCs could be enhanced by exposure to tumor-conditioned medium, and IL-1{beta} was identified as one of factors involved in the stimulation of Hyal2 activity. CD44-mediated signaling plays an important role in the regulation of HA-degrading activity of Hyal2-expressing myeloid cells, since engagement of CD44 receptor with specific monoclonal antibody triggered translocation of Hyal2 enzyme to the cellular surface and also stimulated secretion of IL-1{beta}. Taken together, this work identifies the Hyal2-expressing tumor-associated myeloid cells, and links these cells to the accumulation of LMW-HA in the tumor microenvironment and cancer-related inflammation and angiogenesis.

cancer biology↗

bioRxiv2018

Development of an on-chip detection of Zika virus and antibodies simultaneously using array of nanowells

Zika virus (ZIKV) infections are an emerging health pandemic of significant medical importance. ZIKV appeared recently in the Americas from Africa via the South Pacific. The current outbreak has garnered attention by exhibiting unique characteristics of devastating neurodevelopmental defects in newborns of infected pregnant women. Current guidelines for ZIKV diagnostics developed by the Center of Diseases Control and Prevention (CDC) consist of nucleic acid testing, plaque reduction neutralization test (PRNT), and a serologic test for IgM detection. To better accommodate and comply with these guidelines, we developed a simultaneous on-chip detection of ZIKV and anti-ZIKV antibodies using an array of nanowells. Using on-chip microengraving, we were able to detect anti-ZIKV antibodies and their immunoglobulin isotypes. In parallel, applying on-chip real-time PCR with epifluorescence microscopy, we were able to quantify ZIKV viral load as low as one copy. To test clinical samples of patients at the postconvalescent stage, we analyzed samples from 8 patients. The on-chip nanowells could effectively identify antibodies that reacted against ZIKV envelope protein and their isotypes with high sensitivity and specificity. The small sample requirement with high specificity and sensitivity and combined molecular and serological tests could potentially be very advantageous and beneficial in accurate detection of Zika infection for better disease monitoring and management.

bioengineering↗