Gene Knockdown in Human Rhinovirus 1B Using 2′-OMe-modified si RNAs Results in the Reactivation of the Interferon Response

The aim of this study was to investigate the knockdown efficiency of 2＇-O-methylated （2＇-OMe）-modified small interfering RNAs （siRNAs） on human rhinovirus 1B （HRV1B） replication and the interferon response. Thus, 24 2＇-OMe-modified siRNAs were designed to target HRV1B. The RNA levels of HRV1B, Toll-like receptor 3, melanoma differentiation-associated gene 5, retinoic acid inducible gene-I, and interferons were determined in HRV1B-infected HeLa and BEAS-2B epithelial cells transfected with 2＇-OMe-modified siRNAs. The results revealed that all 2＇-OMe-modified siRNAs interfered with the replication of HRVIB in a cell-specific and transfection efficiency-dependent manner. Viral activation of Toll-like receptor 3, melanoma differentiation-associated gene 5, retinoic acid inducible gene-1, and the interferon response was detected. In conclusion, the 2＇-OMe-modified siRNAs used in this study could interfere with HRV1B replication, possibly leading to the reactivation of the interferon response.

Peptide nanotube loaded with a STING agonist,c-di-GMP,enhance cancer immunotherapy against melanoma

The activation of the stimulating factor of the interferon gene(STING)pathway can enhance the immune response within the tumor.Cyclic diguanylate monophosphate(c-di-GMP)is a negatively charged,hydrophilic STING agonist,however,its effectiveness is limited due to the poor membrane permeability and low bioavailability.Herein,we introduced KL-7 peptide derived from Aβamyloid fibrils that can self-assemble to form nanotubes to load and deliver c-di-GMP,which significantly enhanced c-di-GMP’s effectiveness and then exhibited a robust“in situ immunity”to kill melanoma cells.KL-7 peptide nanotube,also called PNT,was loaded with negatively charged c-di-GMP via electrostatic interaction,which prepared a nanocomposite named c-di-GMP-PNT.Treatment of RAW 264.7 cells(leukemia cells in mouse macrophage)with c-di-GMP-PNT markedly stimulated the secretion of IL-6 and INF-βalong with phospho-STING(Ser365)protein expression,indicating the activation of the STING pathway.In the unilateral flank B16-F10(murine melanoma cells)tumor-bearing mouse model,compared to PNT and cdi-GMP,c-di-GMP-PNT can promote the expression of INF-β,TNF-α,IL-6,and IL-1β.At the same time,up-regulated CD4 and CD8 active T cells kill tumors and enhance the immune response in tumor tissues,resulting in significant inhibition of tumor growth in tumor-bearing mice.More importantly,in a bilateral flank B16-F10 tumor model,both primary and distant tumor growth can also be significantly inhibited by c-di-GMP-PNT.Moreover,c-di-GMP-PNT demonstrated no obvious biological toxicity on the main organs(heart,liver,spleen,lung,and kidney)and biochemical indexes of mice.In summary,our study provides a strategy to overcome the barriers of free c-di-GMP in the tumor microenvironment and c-di-GMP-PNT may be an attractive nanomaterial for anti-tumor immunity.