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Optimization of HIV-1 Envelope DNA Vaccine Candidates within Three Different Animal Models, Guinea Pigs, Rabbits and Cynomolgus Macaques.

Borggren M, Vinner L, Andresen BS, Grevstad B, Repits J, Melchers M, Elvang TL, Sanders RW, Martinon F, Dereuddre-Bosquet N, Bowles EJ, Stewart-Jones G, Biswas P, Scarlatti G, Jansson M, Heyndrickx L, Grand RL, Fomsgaard A - Vaccines (Basel) (2013)

Bottom Line: Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed.Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity.It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology Diagnostics and Virology, Statens Serum Institut, Copenhagen 2300, Denmark.

ABSTRACT
HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb). We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

No MeSH data available.


Related in: MedlinePlus

Comparison of immune response in guinea pigs, rabbits and cynomolgus macaques immunized with plasmid DNA encoding syn.gp140mix. (A) Average IgG response against rgp120IIIb in immunized animals (n = 4). Immunization time points are indicated with arrows. IgG titers in rabbits and guinea pigs were derived from Figure 2A,C. (B) Average percent neutralization against pseudotype virus strains of clade A–C, by week 14 rabbit IgG or guinea pig sera and week 17 macaque sera. From rabbit sera, IgG was purified and used in neutralization at one fixed concentration (250 or 400 µg/mL). Sera from guinea pigs and macaques were diluted 20 and 30 times, respectively, and used in neutralization. Neutralization results of rabbit and guinea pigs were derived and recalculated from Figure 2B,D. (C and D) Macaque sera was tested for neutralization at 1/30 dilution against SF162 and MW965 viruses with the addition of a final immunization with DNA and protein at w17 (* p < 0.001, One-way ANOVA, Friedman’s test with Dunn’s Multiple Comparison Test).
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vaccines-01-00305-f005: Comparison of immune response in guinea pigs, rabbits and cynomolgus macaques immunized with plasmid DNA encoding syn.gp140mix. (A) Average IgG response against rgp120IIIb in immunized animals (n = 4). Immunization time points are indicated with arrows. IgG titers in rabbits and guinea pigs were derived from Figure 2A,C. (B) Average percent neutralization against pseudotype virus strains of clade A–C, by week 14 rabbit IgG or guinea pig sera and week 17 macaque sera. From rabbit sera, IgG was purified and used in neutralization at one fixed concentration (250 or 400 µg/mL). Sera from guinea pigs and macaques were diluted 20 and 30 times, respectively, and used in neutralization. Neutralization results of rabbit and guinea pigs were derived and recalculated from Figure 2B,D. (C and D) Macaque sera was tested for neutralization at 1/30 dilution against SF162 and MW965 viruses with the addition of a final immunization with DNA and protein at w17 (* p < 0.001, One-way ANOVA, Friedman’s test with Dunn’s Multiple Comparison Test).

Mentions: Evaluation of gp120-specific IgG in immunized cynomolgus macaques demonstrated a response already after the initial priming immunizations; however, the antibody titers did not increase with the same magnitude as in rabbits (Figure 5A). Neutralizing capacity of antisera obtained from the immunized cynomolgus macaques was measured in the TZMbl assay against five different HIV-1 virus strains of clade B and C (Figure 5B). Percent neutralization was compared to guinea pig sera and purified rabbit IgG which had been tested against 10 and six viruses, respectively. Macaque and guinea pig sera were tested at a fixed serum dilution and rabbit IgG at a fixed concentration. Four virus strains, SF162, Bx08, BaL and 92Br025, were tested for NAbs from all three animal species. All four viruses demonstrated lower sensitivity to neutralization by macaque antisera as compared to guinea pig sera or rabbit IgG and could not be inhibited to 50% with macaque serum. The remaining virus tested with macaque sera, MNP.ec3, and was easily neutralized by guinea pig sera, but resistant to neutralization by macaque sera.


Optimization of HIV-1 Envelope DNA Vaccine Candidates within Three Different Animal Models, Guinea Pigs, Rabbits and Cynomolgus Macaques.

Borggren M, Vinner L, Andresen BS, Grevstad B, Repits J, Melchers M, Elvang TL, Sanders RW, Martinon F, Dereuddre-Bosquet N, Bowles EJ, Stewart-Jones G, Biswas P, Scarlatti G, Jansson M, Heyndrickx L, Grand RL, Fomsgaard A - Vaccines (Basel) (2013)

Comparison of immune response in guinea pigs, rabbits and cynomolgus macaques immunized with plasmid DNA encoding syn.gp140mix. (A) Average IgG response against rgp120IIIb in immunized animals (n = 4). Immunization time points are indicated with arrows. IgG titers in rabbits and guinea pigs were derived from Figure 2A,C. (B) Average percent neutralization against pseudotype virus strains of clade A–C, by week 14 rabbit IgG or guinea pig sera and week 17 macaque sera. From rabbit sera, IgG was purified and used in neutralization at one fixed concentration (250 or 400 µg/mL). Sera from guinea pigs and macaques were diluted 20 and 30 times, respectively, and used in neutralization. Neutralization results of rabbit and guinea pigs were derived and recalculated from Figure 2B,D. (C and D) Macaque sera was tested for neutralization at 1/30 dilution against SF162 and MW965 viruses with the addition of a final immunization with DNA and protein at w17 (* p < 0.001, One-way ANOVA, Friedman’s test with Dunn’s Multiple Comparison Test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494233&req=5

vaccines-01-00305-f005: Comparison of immune response in guinea pigs, rabbits and cynomolgus macaques immunized with plasmid DNA encoding syn.gp140mix. (A) Average IgG response against rgp120IIIb in immunized animals (n = 4). Immunization time points are indicated with arrows. IgG titers in rabbits and guinea pigs were derived from Figure 2A,C. (B) Average percent neutralization against pseudotype virus strains of clade A–C, by week 14 rabbit IgG or guinea pig sera and week 17 macaque sera. From rabbit sera, IgG was purified and used in neutralization at one fixed concentration (250 or 400 µg/mL). Sera from guinea pigs and macaques were diluted 20 and 30 times, respectively, and used in neutralization. Neutralization results of rabbit and guinea pigs were derived and recalculated from Figure 2B,D. (C and D) Macaque sera was tested for neutralization at 1/30 dilution against SF162 and MW965 viruses with the addition of a final immunization with DNA and protein at w17 (* p < 0.001, One-way ANOVA, Friedman’s test with Dunn’s Multiple Comparison Test).
Mentions: Evaluation of gp120-specific IgG in immunized cynomolgus macaques demonstrated a response already after the initial priming immunizations; however, the antibody titers did not increase with the same magnitude as in rabbits (Figure 5A). Neutralizing capacity of antisera obtained from the immunized cynomolgus macaques was measured in the TZMbl assay against five different HIV-1 virus strains of clade B and C (Figure 5B). Percent neutralization was compared to guinea pig sera and purified rabbit IgG which had been tested against 10 and six viruses, respectively. Macaque and guinea pig sera were tested at a fixed serum dilution and rabbit IgG at a fixed concentration. Four virus strains, SF162, Bx08, BaL and 92Br025, were tested for NAbs from all three animal species. All four viruses demonstrated lower sensitivity to neutralization by macaque antisera as compared to guinea pig sera or rabbit IgG and could not be inhibited to 50% with macaque serum. The remaining virus tested with macaque sera, MNP.ec3, and was easily neutralized by guinea pig sera, but resistant to neutralization by macaque sera.

Bottom Line: Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed.Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity.It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology Diagnostics and Virology, Statens Serum Institut, Copenhagen 2300, Denmark.

ABSTRACT
HIV-1 DNA vaccines have many advantageous features. Evaluation of HIV-1 vaccine candidates often starts in small animal models before macaque and human trials. Here, we selected and optimized DNA vaccine candidates through systematic testing in rabbits for the induction of broadly neutralizing antibodies (bNAb). We compared three different animal models: guinea pigs, rabbits and cynomolgus macaques. Envelope genes from the prototype isolate HIV-1 Bx08 and two elite neutralizers were included. Codon-optimized genes, encoded secreted gp140 or membrane bound gp150, were modified for expression of stabilized soluble trimer gene products, and delivered individually or mixed. Specific IgG after repeated i.d. inoculations with electroporation confirmed in vivo expression and immunogenicity. Evaluations of rabbits and guinea pigs displayed similar results. The superior DNA construct in rabbits was a trivalent mix of non-modified codon-optimized gp140 envelope genes. Despite NAb responses with some potency and breadth in guinea pigs and rabbits, the DNA vaccinated macaques displayed less bNAb activity. It was concluded that a trivalent mix of non-modified gp140 genes from rationally selected clinical isolates was, in this study, the best option to induce high and broad NAb in the rabbit model, but this optimization does not directly translate into similar responses in cynomolgus macaques.

No MeSH data available.


Related in: MedlinePlus