Antibody-mediated enhancement of the rate, magnitude, and responsiveness of vesicular stomatitis virus induced alpha interferon production

Naturally Occurring Fc-Dependent Antibody From HIV-Seronegative Individuals Promotes HIV-Induced IFN-α Production

A majority of adults without HIV infection and with a low risk of HIV-exposure have plasma IgG antibodies that enhance the rate and magnitude of HIV-induced interferon alpha (IFN-α) production. Fc-dependent IgG-HIV complexes induce IFN-α rapidly and in high titers in response to HIV concentrations that are too low to otherwise stimulate an effective IFN-α response. IFN-α promoting antibody (IPA) counters HIV-specific inhibition of IFN-α production, and compensates for the inherent delay in IFN-α production common to HIV infection and other viruses. Naturally occurring IPA has the potential to initiate a potent IFN-α response early in the course of HIV mucosal invasion in time to terminate infection prior to the creation of a pool of persistently infected cells. The current study adds IPA as a mediator of an Fc-dependent antiviral state capable of preventing HIV infection.

Optical Imaging and Gene Therapy with Neuroblastoma-Targeting Polymeric Nanoparticles for Potential Theranostic Applications

Recently, targeted delivery systems based on functionalized polymeric nanoparticles have attracted a great deal of attention in cancer diagnosis and therapy. Specifically, as neuroblastoma occurs in infancy and childhood, targeted delivery may be critical to reduce the side effects that can occur with conventional approaches, as well as to achieve precise diagnosis and efficient therapy. Thus, biocompatible poly(d,l-lactide-co-glycolide) (PLG) nanoparticles containing an imaging probe and therapeutic gene are prepared, followed by modification with rabies virus glycoprotein (RVG) peptide for neuroblastoma-targeting delivery. RVG peptide is a well-known neuronal targeting ligand and is chemically conjugated to PLG nanoparticles without changing their size or shape. RVG-modified nanoparticles are effective in specifically targeting neuroblastoma both in vitro and in vivo. RVG-modified nanoparticles loaded with a fluorescent probe are useful to detect the tumor site in a neuroblastoma-bearing mouse model, and those encapsulating a therapeutic gene cocktail (siMyc, siBcl-2, and siVEGF) significantly suppressed tumor growth in the mouse model. This approach to designing and tailoring of polymeric nanoparticles for targeted delivery may be useful in the development of multimodality systems for theranostic approaches.

Murine B cell response to TLR7 ligands depends on an IFN-beta feedback loop

Type I IFNs play an important, yet poorly characterized, role in systemic lupus erythematosus. To better understand the interplay between type I IFNs and the activation of autoreactive B cells, we evaluated the effect of type I IFN receptor (IFNAR) deficiency in murine B cell responses to common TLR ligands. In comparison to wild-type B cells, TLR7-stimulated IFNAR(-/-) B cells proliferated significantly less well and did not up-regulate costimulatory molecules. By contrast, IFNAR1(-/-) B cells did not produce cytokines, but did proliferate and up-regulate activation markers in response to other TLR ligands. These defects were not due to a difference in the distribution of B cell populations or a failure to produce a soluble factor other than a type I IFN. Instead, the compromised response pattern reflected the disruption of an IFN-beta feedback loop and constitutively low expression of TLR7 in the IFNAR1(-/-) B cells. These results highlight subtle differences in the IFN dependence of TLR7 responses compared with other TLR-mediated B cell responses.