PAP4 Antibody

Definition and Target Specificity

PAP4 Antibody primarily identifies two distinct targets based on literature:

• PAPD4 (PAP-associated domain-containing protein 4): A cytoplasmic RNA-binding protein involved in mRNA stability and post-transcriptional regulation .

• PAP-derived peptides: Specifically, peptide sequences from prostatic acid phosphatase (PAP), a glycoprotein overexpressed in prostate cancer (PCa) .

Notable Findings:

• PAPD4 antibodies are used to study RNA metabolism and viral defense mechanisms .

• Cross-reactivity with orthologs (e.g., mouse, rat) enables comparative studies .

PAP-targeting Antibodies

Functional Insights:

• Anti-PAP antibody [EPR4067] (ab109004) detects PAP in human prostate adenocarcinoma cells and tissues, validated in 3+ publications .

• PAP-specific CD8+ T cells are induced by PAP-based vaccines, enhancing cytotoxic responses against PCa .

PAP4 Peptide in Prostate Cancer Vaccines

• MutPAP42mer Vaccine: A mutated 42-amino-acid PAP peptide (position 116: alanine → leucine) showed enhanced immunogenicity compared to wild-type sequences.

  • Induced 20–60% effector/effector memory CD8+ T cells in murine models when combined with CAF®09 adjuvant .

  • Increased killing of LNCaP prostate cancer cells in vitro .

PAP4 Peptide in Nerve Regeneration

• PAP4 Peptide: Promotes motor function recovery post-peripheral nerve injury in rats.

  • Increased ChAT-positive motoneurons by 40–50% compared to controls .

  • Enhanced axonal regeneration confirmed via FG-labeling assays .

Comparative Analysis of Key Studies

Challenges and Future Directions

• Specificity Issues: Cross-reactivity with non-target proteins (e.g., PAP isoforms) requires rigorous validation .

• Clinical Translation: While PAP-based vaccines show promise, cost and scalability remain barriers .