University of Maryland, Baltimore County

About: University of Maryland, Baltimore County is a education organization based out in Baltimore, Maryland, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 8749 authors who have published 20843 publications receiving 795706 citations. The organization is also known as: UMBC.

HMGB1 Enhances Immune Suppression by Facilitating the Differentiation and Suppressive Activity of Myeloid-Derived Suppressor Cells

Abstract: Chronic inflammation often precedes malignant transformation and later drives tumor progression. Likewise, subversion of the immune system plays a role in tumor progression, with tumoral immune escape now well recognized as a crucial hallmark of cancer. Myeloid-derived suppressor cells (MDSC) are elevated in most individuals with cancer, where their accumulation and suppressive activity are driven by inflammation. Thus, MDSCs may define an element of the pathogenic inflammatory processes that drives immune escape. The secreted alarmin HMGB1 is a proinflammatory partner, inducer, and chaperone for many proinflammatory molecules that MDSCs develop. Therefore, in this study, we examined HMGB1 as a potential regulator of MDSCs. In murine tumor systems, HMGB1 was ubiquitous in the tumor microenvironment, activating the NF-κB signal transduction pathway in MDSCs and regulating their quantity and quality. We found that HMGB1 promotes the development of MDSCs from bone marrow progenitor cells, contributing to their ability to suppress antigen-driven activation of CD4(+) and CD8(+) T cells. Furthermore, HMGB1 increased MDSC-mediated production of IL-10, enhanced crosstalk between MDSCs and macrophages, and facilitated the ability of MDSCs to downregulate expression of the T-cell homing receptor L-selectin. Overall, our results revealed a pivotal role for HMGB1 in the development and cancerous contributions of MDSCs.

The Programmed Death-1 Immune-Suppressive Pathway: Barrier to Antitumor Immunity

Abstract: Programmed death ligand 1 (PD-L1, also known as B7 homolog 1 or CD274) is a major obstacle to antitumor immunity because it tolerizes/anergizes tumor-reactive T cells by binding to its receptor programmed death-1 (CD279), renders tumor cells resistant to CD8(+) T cell- and FasL-mediated lysis, and tolerizes T cells by reverse signaling through T cell-expressed CD80. PD-L1 is abundant in the tumor microenvironment, where it is expressed by many malignant cells, as well as by immune cells and vascular endothelial cells. The critical role of PD-L1 in obstructing antitumor immunity has been demonstrated in multiple animal models and in recent clinical trials. This article reviews the mechanisms by which PD-L1 impairs antitumor immunity and discusses established and experimental strategies for maintaining T cell activation in the presence of PD-L1-expressing cells in the tumor microenvironment.

A Decade of Gamma-Ray Bursts Observed by Fermi-LAT: The Second GRB Catalog

Abstract: The Large Area Telescope (LAT) aboard the Fermi spacecraft routinely observes high-energy emission from gamma-ray bursts (GRBs). Here we present the second catalog of LAT-detected GRBs, covering the first 10 yr of operations, from 2008 to 2018 August 4. A total of 186 GRBs are found; of these, 91 show emission in the range 30–100 MeV (17 of which are seen only in this band) and 169 are detected above 100 MeV. Most of these sources were discovered by other instruments (Fermi/GBM, Swift/BAT, AGILE, INTEGRAL) or reported by the Interplanetary Network (IPN); the LAT has independently triggered on four GRBs. This catalog presents the results for all 186 GRBs. We study onset, duration, and temporal properties of each GRB, as well as spectral characteristics in the 100 MeV–100 GeV energy range. Particular attention is given to the photons with the highest energy. Compared with the first LAT GRB catalog, our rate of detection is significantly improved. The results generally confirm the main findings of the first catalog: the LAT primarily detects the brightest GBM bursts, and the high-energy emission shows delayed onset as well as longer duration. However, in this work we find delays exceeding 1 ks and several GRBs with durations over 10 ks. Furthermore, the larger number of LAT detections shows that these GRBs not only cover the high-fluence range of GBM-detected GRBs but also sample lower fluences. In addition, the greater number of detected GRBs with redshift estimates allows us to study their properties in both the observer and rest frames. Comparison of the observational results with theoretical predictions reveals that no model is currently able to explain all results, highlighting the role of LAT observations in driving theoretical models.

Anger and post-traumatic stress disorder in female crime victims

Abstract: This study examined feelings of anger among female victims of crime and the relation of anger to the development of post-traumatic stress disorder (PTSD). One hundred and sixteen women who had been victims of sexual or nonsexual criminal assaults were compared to a matched comparison group of 50 nonvictimized women on measures of anger and anger expression. Results indicate that victims were angrier than nonvictims. The level of anger was related to various aspects of the assault, such as the use of a weapon and the victim's response to the attack. In addition, the results indicate that elevated anger is positively related to the development of PTSD. Results are discussed in relation to a cognitive/behavioral conceptualization of PTSD.