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Enhanced Efficacy of a Codon-Optimized DNA Vaccine Encoding the Glycoprotein Precursor Gene of Lassa Virus in a Guinea Pig Disease Model When Delivered by Dermal Electroporation.

Cashman KA, Broderick KE, Wilkinson ER, Shaia CI, Bell TM, Shurtleff AC, Spik KW, Badger CV, Guttieri MC, Sardesai NY, Schmaljohn CS - Vaccines (Basel) (2013)

Bottom Line: Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls.Together, these innovations resulted in enhanced efficacy of the vaccine.The vaccinated GPs were never ill and were not viremic at any timepoint.

View Article: PubMed Central - PubMed

Affiliation: Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA. kathleen.cashman@us.army.mil.

ABSTRACT
Lassa virus (LASV) causes a severe, often fatal, hemorrhagic fever endemic to West Africa. Presently, there are no FDA-licensed medical countermeasures for this disease. In a pilot study, we constructed a DNA vaccine (pLASV-GPC) that expressed the LASV glycoprotein precursor gene (GPC). This plasmid was used to vaccinate guinea pigs (GPs) using intramuscular electroporation as the delivery platform. Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls. However, vaccinated GPs experienced transient viremia after challenge, although lower than the mock-vaccinated controls. In a follow-on study, we developed a new device that allowed for both the vaccine and electroporation pulse to be delivered to the dermis. We also codon-optimized the GPC sequence of the vaccine to enhance expression in GPs. Together, these innovations resulted in enhanced efficacy of the vaccine. Unlike the pilot study where neutralizing titers were not detected until after virus challenge, modest neutralizing titers were detected in guinea pigs before challenge, with escalating titers detected after challenge. The vaccinated GPs were never ill and were not viremic at any timepoint. The combination of the codon-optimized vaccine and dermal electroporation delivery is a worthy candidate for further development.

No MeSH data available.


Related in: MedlinePlus

Plasmid Map and Immunoprecipitation and polyacrylamide gel electrophoresis (PAGE) of radiolabeled LASV strain Josiah glycoprotein precursor (GPC, 76 KD). (A) Map of pLASV-GPC cloned into the pWRG7077 vaccine plasmid. (B) Radioimmunoprecipitation and PAGE of LASV GPC and GP2 from COS-7 cell lysate. Expression products from COS-7 cells transfected with (Lane 1) empty vaccine plasmid pWRG7077 or (Lane 2) recombinant pLASV-GPC, and immunoprecipitated with LASV-immune guinea pig serum. The sizes of molecular weight markers M and the location of bands corresponding to GPC and GP2 are indicated.
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vaccines-01-00262-f001: Plasmid Map and Immunoprecipitation and polyacrylamide gel electrophoresis (PAGE) of radiolabeled LASV strain Josiah glycoprotein precursor (GPC, 76 KD). (A) Map of pLASV-GPC cloned into the pWRG7077 vaccine plasmid. (B) Radioimmunoprecipitation and PAGE of LASV GPC and GP2 from COS-7 cell lysate. Expression products from COS-7 cells transfected with (Lane 1) empty vaccine plasmid pWRG7077 or (Lane 2) recombinant pLASV-GPC, and immunoprecipitated with LASV-immune guinea pig serum. The sizes of molecular weight markers M and the location of bands corresponding to GPC and GP2 are indicated.

Mentions: The LASV GPC product was successfully expressed in COS-7 cells from the pLASV-GPC plasmid. Using guinea pig LASV immune serum, it was possible to immunoprecipitate GPC and GP2, which is released from GPC by post-translational cleavage through the action of a host cell subtilase SKI-1/S1P (Figure 1B, Lane 2) [20]. A plasmid map is provided as Figure 1A. Bands for GPC and GP2 do not appear in the untransfected COS cell lysate Figure 1B, Lane 1).


Enhanced Efficacy of a Codon-Optimized DNA Vaccine Encoding the Glycoprotein Precursor Gene of Lassa Virus in a Guinea Pig Disease Model When Delivered by Dermal Electroporation.

Cashman KA, Broderick KE, Wilkinson ER, Shaia CI, Bell TM, Shurtleff AC, Spik KW, Badger CV, Guttieri MC, Sardesai NY, Schmaljohn CS - Vaccines (Basel) (2013)

Plasmid Map and Immunoprecipitation and polyacrylamide gel electrophoresis (PAGE) of radiolabeled LASV strain Josiah glycoprotein precursor (GPC, 76 KD). (A) Map of pLASV-GPC cloned into the pWRG7077 vaccine plasmid. (B) Radioimmunoprecipitation and PAGE of LASV GPC and GP2 from COS-7 cell lysate. Expression products from COS-7 cells transfected with (Lane 1) empty vaccine plasmid pWRG7077 or (Lane 2) recombinant pLASV-GPC, and immunoprecipitated with LASV-immune guinea pig serum. The sizes of molecular weight markers M and the location of bands corresponding to GPC and GP2 are indicated.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494234&req=5

vaccines-01-00262-f001: Plasmid Map and Immunoprecipitation and polyacrylamide gel electrophoresis (PAGE) of radiolabeled LASV strain Josiah glycoprotein precursor (GPC, 76 KD). (A) Map of pLASV-GPC cloned into the pWRG7077 vaccine plasmid. (B) Radioimmunoprecipitation and PAGE of LASV GPC and GP2 from COS-7 cell lysate. Expression products from COS-7 cells transfected with (Lane 1) empty vaccine plasmid pWRG7077 or (Lane 2) recombinant pLASV-GPC, and immunoprecipitated with LASV-immune guinea pig serum. The sizes of molecular weight markers M and the location of bands corresponding to GPC and GP2 are indicated.
Mentions: The LASV GPC product was successfully expressed in COS-7 cells from the pLASV-GPC plasmid. Using guinea pig LASV immune serum, it was possible to immunoprecipitate GPC and GP2, which is released from GPC by post-translational cleavage through the action of a host cell subtilase SKI-1/S1P (Figure 1B, Lane 2) [20]. A plasmid map is provided as Figure 1A. Bands for GPC and GP2 do not appear in the untransfected COS cell lysate Figure 1B, Lane 1).

Bottom Line: Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls.Together, these innovations resulted in enhanced efficacy of the vaccine.The vaccinated GPs were never ill and were not viremic at any timepoint.

View Article: PubMed Central - PubMed

Affiliation: Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA. kathleen.cashman@us.army.mil.

ABSTRACT
Lassa virus (LASV) causes a severe, often fatal, hemorrhagic fever endemic to West Africa. Presently, there are no FDA-licensed medical countermeasures for this disease. In a pilot study, we constructed a DNA vaccine (pLASV-GPC) that expressed the LASV glycoprotein precursor gene (GPC). This plasmid was used to vaccinate guinea pigs (GPs) using intramuscular electroporation as the delivery platform. Vaccinated GPs were protected from lethal infection (5/6) with LASV compared to the controls. However, vaccinated GPs experienced transient viremia after challenge, although lower than the mock-vaccinated controls. In a follow-on study, we developed a new device that allowed for both the vaccine and electroporation pulse to be delivered to the dermis. We also codon-optimized the GPC sequence of the vaccine to enhance expression in GPs. Together, these innovations resulted in enhanced efficacy of the vaccine. Unlike the pilot study where neutralizing titers were not detected until after virus challenge, modest neutralizing titers were detected in guinea pigs before challenge, with escalating titers detected after challenge. The vaccinated GPs were never ill and were not viremic at any timepoint. The combination of the codon-optimized vaccine and dermal electroporation delivery is a worthy candidate for further development.

No MeSH data available.


Related in: MedlinePlus