As evidence has mounted that virus-infected cells, such as cancer cells, negatively regulate the function of T-cells via immune checkpoints, it has become increasingly clear that viral infections similarly exploit immune checkpoints as an immune system escape mechanism. Although immune checkpoint therapy has been successfully used in cancer treatment, numerous studies have suggested that such therapy may also be highly relevant for treating viral infection, especially chronic viral infections. However, it has not yet been applied in this manner. Here, we reviewed recent findings regarding immune checkpoints in viral infections, including COVID-19, and discussed the role of immune checkpoints in different viral infections, as well as the potential for applying immune checkpoint blockades as antiviral therapy.

Herein, MoS₂ nanoflowers were deposited on a plasmonic interface for a sensitivity-enhanced immunoassay by increasing the amount of the loaded antibodies.

Background: Apocynum venetum leaves are used as a kind of phytomedicine and the main ingredient in some traditional Chinese medicine products for the relief of colitis. To understand the bioactive constituents of A. venetum L., we did a phytochemistry study and investigated anti-Inflammatory effects of compounds and explored the underlying mechanisms. Methods: We isolated compounds from ethanol extract of A. venetum L. leaf and detected the most effective compound by NO inhibition assay. We investigated anti-Inflammatory effects on dextran sulfate sodium (DSS)-induced colitis mice and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The disease activity index was determined by scores of body weight loss, diarrhea and rectal bleeding; histological damage was analyzed by H&E staining; macrophages change in the colon were analyzed by immunohistochemistry (IHC); myeloperoxidase activity was measured by myeloperoxidase assay kits; levels of proinflammatory cytokines were determined by qPCR and ELISA; protein production such as COX-2, iNOS, STAT3 and ERK1/2 were determined by western blotting. Results: We isolated uvaol from ethanol extract of A. venetum L. leaf and found uvaol has excellent potential of inhibiting NO production. We further found uvaol could attenuate disease activity index (DAI), colon shortening, colon injury, and colonic myeloperoxidase activity in DSS-induced colitis mice. Moreover, uvaol significantly reduces mRNA expression and production of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, and MCP-1) and infiltration of macrophages in colonic tissues of colitis mice. Studies on LPS challenged murine macrophage RAW246.7 cells also revealed that uvaol reduces mRNA expression and production of pro-inflammatory cytokines and mediators. Mechanically, uvaol inhibits the pro-inflammatory ERK/STAT3 axis in both inflamed colonic tissues and macrophages. Conclusions: A. venetum leaf contains uvaol and uvaol has potent anti-inflammatory effects on DSS-induced experimental colitis and LPS-stimulated RAW264.7 macrophage cells. These results suggest uvaol is a prospective anti-inflammatory agent for colonic inflammation.

Aim: SARS-coronavirus 2 main protease (Mpro) and host toll-like receptors (TLRs) were targeted to screen potential inhibitors among traditional antiviral medicinal plants. Materials & methods: LeDo...

Indigo naturalis (also known as Qing-dai, or QD), a traditional Chinese medicine, has been widely used as an anticolitis regimen in the clinical practice of Chinese medicine. However, the precise mechanisms behind its efficacy remain unknown. We investigated the protective effects and associated molecular mechanisms of QD in DSS-induced colitis in mice. We found that QD administration attenuated DSS-induced colon shortening, tissue damage, and the disease activity index during the onset of colitis. Moreover, QD administration significantly suppressed colonic MPO activity and increased the activities of colonic T-SOD, CAT, and GSH-Px, as well the expression of p-AMPK and Nrf-2 in colon tissues of colitic mice. In addition, QD was capable of reducing the colonic Th1 and Th17 cell cytokines, the frequencies of Th1 and Th17 cells, and the phosphorylation of p-STAT1 and p-STAT3 in the mesenteric lymph nodes of colitic mice. An in vitro assay showed that QD significantly suppressed the differentiation of Th1 and Th17 cells. These findings suggest that QD has the potential to alleviate experimental colitis by suppressing colonic oxidative stress and restraining colonic Th1/Th17 responses, which are associated with activating AMPK/Nrf-2 signals and inhibiting STAT1/STAT3 signals, respectively. These findings also support QD as an effective regimen in the treatment of IBD.