Any individual virus can infect only a limited range of hosts, and most plant species are "nonhosts" to a given virus; i.e., all members of the species are insusceptible to the virus. In nonhost plants, the factors that control virus resistance are not genetically tractable, and how the host range of a virus is determined remains poorly understood. Tomato (Solanum lycopersicum) is a nonhost spe...

BACKGROUND Among persons in North America who are newly infected with the human immunodeficiency virus (HIV), the prevalence of transmitted resistance to antiretroviral drugs has been estimated at 1 to 11 percent. METHODS We performed a retrospective analysis of susceptibility to antiretroviral drugs before treatment and drug-resistance mutations in HIV in plasma samples from 377 subjects wit...

Pathogen entry route can have a strong impact on the result of microbial infections in different hosts, including insects. Drosophila melanogaster has been a successful model system to study the immune response to systemic viral infection. Here we investigate the role of the Toll pathway in resistance to oral viral infection in D. melanogaster. We show that several Toll pathway components, incl...

During systemic infections, viruses move long distances through the plant vascular system. The long-distance movement of cauliflower mosaic virus (CaMV) in Arabidopsis has been examined using a whole plant in situ hybridization technique called plant skeleton hybridization. CaMV moves long distance through the phloem largely following the flow of photoassimilates from source to sink leaves. Dur...

Passage of hepatitis C virus (HCV) in human hepatoma cells resulted in populations that displayed partial resistance to alpha interferon (IFN-α), telaprevir, daclatasvir, cyclosporine, and ribavirin, despite no prior exposure to these drugs. Mutant spectrum analyses and kinetics of virus production in the absence and presence of drugs indicate that resistance is not due to the presence of drug ...

ABSTRACT Five tropical maize lines were tested and compared with the susceptible control line B73 for resistance to Maize stripe virus (MStV) and Maize mosaic virus (MMV), both propagatively transmitted by the planthopper Peregrinus maidis (Homoptera: Delphacidae). Resistance to each virus was evaluated separately by artificial inoculations with planthoppers viruliferous for either one virus or...

A sensitive biological assay has been developed for studying the frequency of virus induction from mouse cells containing poorly infectious endogenous C-type viruses. A low spontaneous frequency of virus activation of one but not a second endogenous virus of BALB/c cells has been demonstrated. The resistance of BALB/c cells to superinfection by the more inducible virus appears to be absolute, w...

A better understanding of virus resistance mechanisms can offer more effective strategies to control virus diseases. Papaya ringspot virus (PRSV), Potyviridae, causes severe economical losses in papaya and cucurbit production worldwide. However, no resistance gene against PRSV has been identified to date. This study aimed to identify candidate PRSV resistance genes using cDNA-AFLP analysis and ...

Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are the most prevalent deadly chronic viral diseases. HIV is treated by small molecule inhibitors. HBV is treated by immunomodulation and small molecule inhibitors. HCV is currently treated primarily by immunomodulation but many small molecules are in clinical development. Although HIV is a retrovirus, HBV ...

1. As mice grow older they acquire a resistance to peripheral inoculation with the Indiana and New Jersey strains of vesicular stomatitis virus and to some extent also to Western equine encephalomyelitis virus, but little or none to the Eastern strain. 2. While some mice may become resistant as early as the 30th day of life, others may still be susceptible at 1 year of age. 3. This resistance i...