RESUMO
Herpes simplex virus type 1 (HSV-1) is a common virus of mankind and HSV-1 infections are a significant cause of blindness. The current antiviral treatment of herpes infection relies on acyclovir and related compounds. However, acyclovir resistance emerges especially in the long term prophylactic treatment that is required for prevention of recurrent herpes keratitis. Earlier we have established antiviral siRNA swarms, targeting sequences of essential genes of HSV, as effective means of silencing the replication of HSV in vitro or in vivo. In this study, we show the antiviral efficacy of 2´-fluoro modified antiviral siRNA swarms against HSV-1 in human corneal epithelial cells (HCE). We studied HCE for innate immunity responses to HSV-1, to immunostimulatory cytotoxic double stranded RNA, and to the antiviral siRNA swarms, with or without a viral challenge. The panel of studied innate responses included interferon beta, lambda 1, interferon stimulated gene 54, human myxovirus resistance protein A, human myxovirus resistance protein B, toll-like receptor 3 and interferon kappa. Our results demonstrated that HCE cells are a suitable model to study antiviral RNAi efficacy and safety in vitro. In HCE cells, the antiviral siRNA swarms targeting the HSV UL29 gene and harboring 2´-fluoro modifications, were well tolerated, induced only modest innate immunity responses, and were highly antiviral with more than 99% inhibition of viral release. The antiviral effect of the 2'-fluoro modified swarm was more apparent than that of the unmodified antiviral siRNA swarm. Our results encourage further research in vitro and in vivo on antiviral siRNA swarm therapy of corneal HSV infection, especially with modified siRNA swarms.
Assuntos
Herpes Simples , Herpesvirus Humano 1 , Aciclovir/metabolismo , Aciclovir/farmacologia , Antivirais/metabolismo , Antivirais/farmacologia , Células Epiteliais/metabolismo , Herpes Simples/genética , Herpes Simples/terapia , Herpesvirus Humano 1/fisiologia , Humanos , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Replicação Viral/genéticaRESUMO
Herpes simplex virus type 1 (HSV-1) is the only FDA- and EMA- approved oncolytic virus, and accordingly, many potential oncolytic HSVs (oHSV) are in clinical development. The utilized oHSV parental strains are, however, mostly based on laboratory reference strains, which may possess a compromised cytolytic capacity in contrast to circulating strains of HSV-1. Here, we assess the phenotype of thirty-six circulating HSV-1 strains from Finland to uncover their potential as oHSV backbones. First, we determined their capacity for cell-to-cell versus extracellular spread, to find strains with replication profiles favorable for each application. Second, to unfold the differences, we studied the genetic diversity of two relevant viral glycoproteins (gB/UL27, gI/US7). Third, we examined the oncolytic potential of the strains in cells representing glioma, lymphoma, and colorectal adenocarcinoma. Our results suggest that the phenotype of a circulating isolate, including the oncolytic potential, is highly related to the host cell type. Nevertheless, we identified isolates with increased oncolytic potential in comparison with the reference viruses across many or all of the studied cancer cell types. Our research emphasizes the need for careful selection of the backbone virus in early vector design, and it highlights the potential of clinical isolates as backbones in oHSV development.
Assuntos
Herpes Simples , Herpesvirus Humano 1 , Terapia Viral Oncolítica , Vírus Oncolíticos , Finlândia , Herpes Simples/genética , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/metabolismo , Humanos , Terapia Viral Oncolítica/métodos , Vírus Oncolíticos/genéticaRESUMO
Acyclovir is the drug of choice for the treatment of herpes simplex virus (HSV) infections. Acyclovir-resistant HSV strains may emerge, especially during long-term drug use, and subsequently cause difficult-to-treat exacerbations. Previously, we set up a novel treatment approach, based on enzymatically synthesized pools of siRNAs, or siRNA swarms. These swarms can cover kilobases-long target sequences, reducing the likelihood of resistance to treatment. Swarms targeting the UL29 essential gene of HSV-1 have demonstrated high efficacy against HSV-1 in vitro and in vivo. Here, we assessed the antiviral potential of a UL29 siRNA swarm against circulating strains of HSV-1, in comparison with acyclovir. All circulating strains were sensitive to both antivirals, with the half-maximal inhibitory concentrations (IC50) in the range of 350-1911 nM for acyclovir and 0.5-3 nM for the UL29 siRNA swarm. Additionally, we showed that an acyclovir-resistant HSV-1, devoid of thymidine kinase, is highly sensitive to UL29 siRNA treatment (IC50 1.0 nM; Imax 97%). Moreover, the detected minor variations in the RNAi target of the HSV strains had no effect on the potency or efficacy of UL29 siRNA swarm treatment. Our findings support the development of siRNA swarms for the treatment of HSV-1 infections, in order to circumvent any potential acyclovir resistance.
Assuntos
Aciclovir/farmacologia , Proteínas de Ligação a DNA/genética , Herpes Simples/virologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Proteínas Virais/genética , Aciclovir/uso terapêutico , Animais , Chlorocebus aethiops , Relação Dose-Resposta a Droga , Farmacorresistência Viral/efeitos dos fármacos , Farmacorresistência Viral/genética , Herpes Simples/terapia , Herpesvirus Humano 1/classificação , Herpesvirus Humano 1/isolamento & purificação , Humanos , Concentração Inibidora 50 , Células VeroRESUMO
Chemical modifications of small interfering (si)RNAs are used to enhance their stability and potency, and to reduce possible off-target effects, including immunogenicity. We have earlier introduced highly effective antiviral siRNA swarms against herpes simplex virus (HSV), targeting 653 bp of the essential UL29 viral gene. Here, we report a method for enzymatic production and antiviral use of 2'-fluoro-modified siRNA swarms. Utilizing the RNA-dependent RNA polymerase from bacteriophage phi6, we produced 2'-F-siRNA swarms containing either all or a fraction of modified adenosine, cytidine or uridine residues in the antisense strand of the UL29 target. The siRNA containing modified pyrimidines demonstrated high resistance to RNase A and the antiviral potency of all the UL29-specific 2'-F-siRNA swarms was 100-fold in comparison with the unmodified counterpart, without additional cytotoxicity. Modest stimulation of innate immunity signaling, including induced expression of both type I and type III interferons, as well as interferon-stimulated gene 54, by 2'-F-cytidine and 2'-F-uridine modified siRNA swarms occurred at early time points after transfection while the 2'-F-adenosine-containing siRNA was similar to the unmodified antiviral siRNA swarm in this respect. The antiviral efficacy of the 2'-F-siRNA swarms and the elicited cellular innate responses did not correlate suggesting that innate immunity pathways do not significantly contribute to the observed enhanced antiviral activity of the modified siRNAs. The results support further applications of enzymatically produced siRNA molecules with incorporated adenosine nucleotides, carrying fluoro-modification on ribose C2' position, for further antiviral studies in vitro and in vivo.
Assuntos
Antivirais/farmacologia , Sobrevivência Celular , Herpesvirus Humano 1/efeitos dos fármacos , Imunidade Inata , RNA Interferente Pequeno/farmacologia , RNA Polimerase Dependente de RNA/metabolismo , Adenosina/metabolismo , Bacteriófago phi 6/enzimologia , Linhagem Celular , Linhagem Celular Tumoral , Citidina/metabolismo , Proteínas de Ligação a DNA/antagonistas & inibidores , Herpesvirus Humano 1/imunologia , Humanos , RNA Interferente Pequeno/síntese química , Transfecção , Uridina/metabolismo , Proteínas Virais/antagonistas & inibidoresRESUMO
We report the formation of a tetrapallada-macrocycle induced by an unusual transmetallation, in which an anionic bidentate chelate ligand is replaced by a phenyl ligand from phenylboronic acid, leaving the chloride ligands intact.
RESUMO
Novel metal-organic frameworks [Eu2L3(DMSO)2(MeOH)2] x 2 DMSO x 3 H2O, 1, and [Zn2L2(DMSO)2] x 1.6 H2O, 2, (L = 4,4'-ethyne-1,2-diyldibenzoate) have been synthesized and structurally characterized. Compound 1 is a 3D open framework while 2 features interpenetrating 2D sheets in the crystal lattice. Both compounds have been characterized with X-ray crystallography, elemental analysis, and thermogravimetric analysis. Compounds 1 and 2 are red and blue-green luminescent, respectively, in the solid state at ambient temperature. Thermogravimetric analysis implies that the extensive interpenetration stabilizes the lattice of 2, although it diminishes the porosity at the same time. The luminescence of 1 can be reversibly quenched and restored by the addition and removal of iodine.