Compositions and methods for reducing and detecting viral infection

A method for screening one or more one or more candidate compounds for activity in altering the level of virus infection of a mammalian host cell, comprising

• a) providing
• i) a virus,
• ii) a mammalian host cell that is susceptible to said virus, and
• iii) said one or more candidate compounds,
• b) contacting said mammalian host cell with said virus and with said one or more candidate compounds under conditions for infection of said mammalian host cell with said virus, to produce a test contacted cell,
• c) contacting said mammalian host cell with said virus, in the absence of said one or more candidate compounds, under conditions for infection of said transgenic mammalian cell with said virus, to produce a control contacted cell, and
• d) measuring the level of virus infection of said test contacted cell and of said control contacted host cell.

A method for screening one or more candidate compounds for altering the level of expression of one or more virus proteins, comprising

• a) providing
• i) a first cell that expresses a first heterologous nucleotide sequence encoding a heterologous polypeptide, wherein said first heterologous nucleotide sequence is optimized for gene expression based on codon bias of said virus,
• ii) a second cell that expresses a second heterologous nucleotide sequence encoding said heterologous polypeptide, wherein said second heterologous nucleotide sequence is optimized for gene expression based on codon bias of a cell that is permissive to said virus, and
• iii) said one or more candidate compounds,
• b) contacting said one or more candidate compounds with said first cell to produce a first contacted cell,
• c) contacting said one or more candidate compounds with said second cell to produce a second contacted cell, and
• d) measuring the level of expression of said heterologous polypeptide in said first contacted cell and in said second contacted cell.

A method for identifying one or more Schlafen (Slfn) polymorphisms as altering the level of risk of a subject to infection by a virus, comprising

• a) providing
• i) a first sample comprising genomic Schlafen (Slfn) sequence from a first population of subjects infected by said virus, and
• ii) a second sample comprising genomic Schlafen (Slfn) sequence from a second population of subjects not infected by said virus,
• b) determining the presence of
• i) wild type Schlafen (Slfn) gene sequence in said first sample and in said second sample, and
• ii) one or more Schlafen (Slfn) polymorphisms in said first sample and in said second sample,
• c) measuring the ratio of said one or more Schlafen (Slfn) polymorphisms relative to said wild type Schlafen (Slfn) gene sequence in
• i) said first sample, and
• ii) in said second sample,
• wherein measuring a difference in said ratio in said first sample relative to said ratio in said second sample identifies said one or more Schlafen (Slfn) polymorphisms as altering the level of risk of said mammalian subject to infection by said virus.