1. Selective activation of cannabinoid receptor 2 regulates Treg/Th17 balance to ameliorate neutrophilic asthma in mice
Chaochao Wei, Linhui Huang, Yamei Zheng, Xingjun Cai Ann Transl Med. 2021 Jun;9(12):1015. doi: 10.21037/atm-21-2778.
Background: The cannabinoid receptor 2 (CNR2) plays a critical role in relieving asthma, with the mechanism still unclear. We aimed to investigate the mechanism of the CNR2 agonist (β-caryophyllene, β-Car) in regulating the balance of regulatory T cells (Treg) and T helper cell 17 (Th17) and thus its role in asthma. Methods: The study group of 50 pathogen-free female BALB/c mice were randomly divided at 6-8 weeks old into five groups of Control, Asthma, Asthma + β-Car (10 mg/kg), Asthma + β-Car + SR144528 (specific CNR2 antagonist, 3 mg/kg), and Asthma + β-Car + CMD178 (inhibitor of Treg cell, 10 mg/kg). ELISA was conducted to evaluate the main inflammatory cytokines [interleukin (IL)-6, IL-8, and tumor necrosis factor-α], and those secreted by Treg (transforming growth factor-β and IL-10), and Th17 (IL-17A and IL-22). Markers of Treg and Th17 cells were assessed by flow cytometry. In vitro, the CD4+ T cells were sorted and directed to differentiate to Treg and Th17 cells. The expression levels of CNR2, STAT5 and JNK1/2 were investigated by western blot and immunofluorescence assay. Results: β-Car relieved neutrophilic asthma severity in mice by elevating the marker genes' expression of Treg and inhibiting those of Th17, causing an increased proportion of Treg to Th17. β-Car also promoted the directed differentiation of CD4+ T cells into Treg, but not Th17. Activation of the CNR2 regulated the Treg/Th17 balance and relieved neutrophilic asthma possibly through promotion of phosphorylation of STAT5 and JNK1/2. Conclusions: The effect of the selective CNR2 agonist activating STAT5 and JNK1/2 signaling was to change the Treg/Th17 balance and reduce the inflammatory reaction, thus ameliorating neutrophilic asthma in a mouse model.
2. Inhibiting IL-2 signaling and the regulatory T-cell pathway using computationally designed peptides
Tammy Price-Troska, Zhi-Zhang Yang, David Diller, Alexander Bayden, Mark Jarosinski, Joseph Audie, Stephen M Ansell Invest New Drugs. 2019 Feb;37(1):9-16. doi: 10.1007/s10637-018-0606-9. Epub 2018 Apr 26.
Background Increased serum levels of soluble interleukin-2 (IL-2) receptor alpha (sIL-2Rα) are an indicator of poor prognosis in patients with B-cell non-Hodgkin lymphoma (NHL). By binding to IL-2, sIL-2Rα upregulates Foxp3 expression and induces the development of regulatory T (Treg) cells. Methods To inhibit the binding of IL-2 to sIL-2Rα with the goal of suppressing the induction of Foxp3 and decreasing Treg cell numbers, we developed peptides by structure-based computational design to disrupt the interaction between IL-2 and sIL-2Rα. Each peptide was screened using an enzyme-linked immunosorbent assay (ELISA), and 10 of 22 peptides showed variable capacity to inhibit IL-2/sIL-2Rα binding. Results We identified a lead candidate peptide, CMD178, which consistently reduced the expression of Foxp3 and STAT5 induced by IL-2/sIL-2Rα signaling. Furthermore, production of cytokines (IL-2/interferon gamma [IFN-γ]) and granules (perforin/granzyme B) was preserved in CD8+ T cells co-cultured with IL-2-stimulated CD4+ T cells that had been pretreated with CMD178 compared to CD8+ cells co-cultured with untreated IL-2-stimulated CD4+ T cells where it was inhibited. Conclusions We conclude that structure-based peptide design can be used to identify novel peptide inhibitors that block IL-2/sIL-2Rα signaling and inhibit Treg cell development. We anticipate that these peptides will have therapeutic potential in B-cell NHL and other malignancies.
