Evaluation of O-alkyl and aryl sulfonyl aromatic and heteroaromatic amidoximes as novel potent DNA photo-cleavers.

Several stable O-alkyl and aryl sulfonyl conjugated p-nitro-Ph and o-, m-, p-pyridine N'-hydroxy imidamides, were subjected to UV irradiation at 312 nm with supercoiled circular plasmid DNA pBluescript KS II. The generated amidinyl and sulfonyloxyl radicals led to effective DNA photo-cleavage. Both alkyl and aryl sulfonyl derivatives were active and the order p-pyridine > p-nitro-Ph > o-pyridine > m-pyridine was schematized for the N'-hydroxy imidamides moiety. Calf thymus-DNA affinity studies which comprised UV interactions, viscosity experiments and competitive studies with ethidium bromide showed good to excellent affinity of the compounds. These properties revealed sulfonyl amidoximes as novel effective DNA-photo-cleavers and may serve in the discovery of new leads for "on demand" biotechnological and medical applications.

Endogenously produced interferon alpha protects mice from herpes simplex virus type 1 corneal disease.

Intravenous (i.v.) injection of u.v. light-inactivated herpes simplex virus type 1 (UV HSV-1) at the time of HSV-1 corneal infection reduced the cytotoxic T lymphocyte (CTL) response to HSV-1, and significantly reduced the incidence of HSV-1-induced corneal stromal disease in A/J mice. The spread of HSV-1 through the eye after corneal infection, detected using engineered HSV-1 (US3::Tn5-lacZ) with the lacZ gene under the transcriptional control of the viral late gene promoter for glycoprotein C, was also markedly reduced by i.v. UV HSV-1 injection. The restriction of HSV-1 corneal invasiveness in i.v. UV HSV-1-injected mice preceded the onset of a detectable specific cell-mediated or humoral immune response to HSV-1, and was accompanied by an elevated serum titre of interferon (IFN-alpha), reversed by anti-IFN-alpha/beta antibody, and mimicked by systemic IFN-alpha treatment. IFN-alpha-treated mice developed a normal CTL response to HSV-1 after corneal infection, but the corneal invasiveness of the virus was markedly reduced and none of the treated mice developed corneal stromal disease. Together with our previous findings that HSV-1-specific CTLs participate in the pathogenesis of corneal stromal disease, these results indicate that i.v. injection of UV HSV-1 at the time of corneal infection may prevent stromal disease by the combined effects of IFN-mediated reduction of the spread of virus in the cornea and inhibition of the activity of the HSV-specific T lymphocytes that induce tissue destruction in the corneal stroma.