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ORF7a is an accessory protein common to SARS-CoV1 and the recently discovered SARS-CoV2, which is causing the COVID-19 pandemic. The ORF7a protein has a structural homology with ICAM-1 which binds to the T lymphocyte integrin receptor LFA-1. As COVID-19 has a strong immune component as part of the disease, we sought to determine whether SARS-CoV2 would have a similar structural interaction with LFA-1. Using molecular docking simulations, we found that SARS-CoV2 ORF7a has the key structural determinants required to bind LFA-1 but also the related leukocyte integrin Mac-1, which is also known to be expressed by macrophages. Our study shows that SARS-CoV2 ORF7a protein has a conserved Ig immunoglobulin-like fold containing an integrin binding site that provides a mechanistic hypothesis for SARS-CoV2's interaction with the human immune system. This suggests that experimental investigation of ORF7a-mediated effects on immune cells such as T lymphocytes and macrophages (leukocytes) could help understand the disease further and develop effective treatments.
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http://dx.doi.org/10.1042/BSR20203837 | DOI Listing |
Sci Adv
September 2025
Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.
HIV-1 evades immune responses by modulating plasma membrane receptors. Using a flow cytometry-based screening, we profiled 332 surface receptors on HIV-1-infected primary CD4 T cells and identified 23 down-regulated receptors, including known targets such as CD4, MHCI, CCR7, and CD62L. CD96, an inhibitory natural killer (NK) cell receptor poorly studied in human CD4 T cells, was markedly down-regulated.
View Article and Find Full Text PDFCurr Drug Targets
August 2025
Department of Medicinal Biotechnology, College of Health Science, Dong-A University, Busan, 49315, Republic of Korea.
Amylin is a thirty-seven amino acid peptide hormone that is secreted from the pancreas with insulin. The peptide hormone amylin activates its receptors in the brain to regulate blood glucose and food appetite. Interestingly, the amylin receptor is the heterodimer of the calcitonin receptor (which is the receptor for the peptide hormone calcitonin) and an accessory protein called receptor activity-modifying protein.
View Article and Find Full Text PDFAppl Environ Microbiol
September 2025
Department of Biological Sciences, University of Maryland - Baltimore County, Baltimore, Maryland, USA.
Unlabelled: Microbial deconstruction of plant polysaccharides is important for environmental nutrient cycling, and bacteria proficient at this process have extensive suites of polysaccharide-specific enzymes. In the gram-negative saprophyte , genome annotation suggests that 17 genes are predicted to encode Carbohydrate-Active enZymes (CAZymes) with roles in cellulose degradation; however, previous work suggested that only a subset of these genes is essential. Building upon that work, here, we identify the required and minimally sufficient set of enzymes for complete degradation of cellulose using a combination of transcriptomics, gene deletion analysis, heterologous expression studies, and metabolite analysis.
View Article and Find Full Text PDFCell Host Microbe
August 2025
Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA. Electronic address:
Bacteria counter bacteriophage threats using diverse anti-phage systems often encoded on prophages within hotspots for accessory genes. These prophages must ensure that encoded defense systems do not inhibit their spread. Here, we discover two anti-phage defense elements, RemS and PokE, encoded within the Gifsy-3 prophage of Salmonella enterica Typhimurium 14028 that restrict phage infection without affecting the lytic cycle of Gifsy-3.
View Article and Find Full Text PDFPLoS Pathog
September 2025
Department of Microbiology and Immunology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina, United States of America.
Antiretroviral therapy (ART) has dramatically improved the clinical prognosis for people with HIV and prevents HIV transmission. However, ART does not cure HIV infection because of a persistent, latent viral reservoir in long-lived cells such as central memory CD4+ T (TCM) cells. Eliminating or preventing reservoir formation will require a better understanding of HIV-1 latency establishment.
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