Influenza Virus Genes and Expression Vectors

Expression vectors are used to introduce new genomic material into a cell. The new DNA is inserted into an expression vector, such as a plasmid. This vector is then introduced into the host. The newly introduced DNA becomes part of the genome of the host cell. The expression vector must have a promoter region that will allow for expression of the gene (without the correct promoter, the plasmid will remain untranslated).

Methods

A full-length cDNA copy of the HA gene of influenza virus TyIr83 A/Ty/Ir/1/83 (H5N8) is an antigenic variant of CkHK97 that was isolated from turkeys. was ligated into the pJW4303 vector under the control of a cytomegalovirus (CMV) immediate-early promoter (pTyIrHA).

A full-length cDNA copy of the HA gene of HK97 was cloned into pCAGGS/MCS (pHKHA). This plasmid contained a chicken beta-actin promoter.

 

pHKHA and pTyIrHA

 

 

Questions to Ponder

•  What is the purpose of using TyIr83? answer TyIr83 (H5N8) is an antigenic variant strain of influenza A. pTyIrHA is used to demonstrate whether or not immunization with HA DNA will protect against infection by antigenic variant strains inwhich the HA differs slightly from the primary immunizing antigen.

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