A29L Antibody

Definition and Biological Role of A29L Protein

The A29L protein is a 110-amino-acid surface protein expressed on the intracellular mature virion (IMV) of MPXV. It facilitates viral entry by binding heparan sulfate on host cells and serves as a major antigenic target for neutralizing antibodies . Homologous to the vaccinia virus A27L protein, A29L is evolutionarily conserved across orthopoxviruses .

Key Domains

• Heparan-binding domain (HBD): Mediates viral attachment to host cells .

• Epitope regions: Linear epitopes (e.g., 21–49 aa) near the HBD are critical for neutralization .

Antibody Binding Mechanisms

A29L antibodies block viral adhesion by targeting epitopes adjacent to the HBD, disrupting interactions with glycosaminoglycans (GAGs) .

Key Antibodies and Neutralization Profiles

Synergistic Effects

• Combining 9F8, 3A1, and 2D1 antibodies enhances neutralization against vaccinia virus (VACV) by >90% .

Diagnostic Performance

Therapeutic Potential

• Prophylactic administration of 9F8 in mice provided complete protection against VACV challenge .

mRNA Immunization

• BALB/c mice immunized with A29L mRNA-LNP produced high-affinity antibodies (EC₅₀ < 10 nM) within 24 days .

Hybridoma Technology

• mAbs 1E12 and 4B2 demonstrated specificity in Western blotting, IFA, and immunoprecipitation .

Cross-Reactivity and Specificity

Clinical Relevance

• Seropositivity: 94% of MPXV-infected individuals developed anti-A29L IgG antibodies within 21 days .

• Vaccine Development: A29L is a candidate antigen for mRNA and protein subunit vaccines due to its immunodominance .