GGP5 Antibody

Definition and Biological Significance of GP5

GP5 is a glycosylated envelope protein encoded by the ORF5 gene of the Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). It is also implicated in human breast cancer progression . Key characteristics include:

GP5 Antibodies in Virology

GP5 is a primary target for neutralizing antibodies in PRRSV research.

Key Findings:

• Neutralizing Epitopes:

  • Epitope B (amino acids 36–52) induces neutralizing antibodies, while epitope A suppresses their production .

  • Monoclonal antibodies (mAbs) against GP5 exhibit strain-specific neutralization .

  • Example: mAb BNW7p5c4 neutralizes homologous PRRSV strains (e.g., ATP) but fails against heterologous strains (e.g., VR2332) .

• Glycosylation Impact:

  • N-linked glycosylation at N44 is critical for PRRSV infectivity. Mutations at N34/N51 enhance antibody neutralization sensitivity .

Table 1: GP5 Antibody Neutralization Efficacy in PRRSV

GP5 in Breast Cancer and Antibody Applications

GP5 overexpression in breast cancer (BC) correlates with tumor progression via the PI3K/AKT/EMT pathway .

Research Highlights:

• Expression Levels:

  • GP5 mRNA is 3–5× higher in BC tissues compared to paracancerous tissues .

  • Associated with higher TNM stages and HER2 negativity .

• Functional Studies:

  • GP5 knockdown reduces BC cell proliferation and invasion by 40–60% .

  • Anti-GP5 antibodies (e.g., A03425) are used to detect GP5 in IHC and WB assays .

Mechanistic Insights from Proteomics

GP5 interacts with host proteins to modulate immune responses:

• Antigen Processing Inhibition:

  • GP5 downregulates SLA-II (MHC-II) expression, impairing CD4+ T-cell activation .

  • Key interacting proteins: TAP1, TAP2, CANX, CALR .

• Viral Replication:

  • GP5 overexpression suppresses interferon (IFN-β) to promote PRRSV replication .

Recent Advances and Challenges

• Vaccine Development:

  • GP5-based vaccines show promise but face challenges due to antigenic variability .

  • Strategies like PADRE epitope insertion improve neutralizing antibody responses .

• Therapeutic Targeting in Cancer:

  • GP5 inhibition reduces metastasis in BC models .