27 kDa cell wall Antibody

Table 1: Key 27 kDa Cell Wall/Membrane Antigens and Associated Antibodies

Pathogen Neutralization

• scFv-VRC01: Refolded scFv-VRC01 binds HIV-1 gp120 with high affinity, confirmed via Far-Western blotting .

• Anti-DRAP27: Reduces diphtheria toxin cytotoxicity by 80% in Vero cells by blocking receptor clustering .

Diagnostic and Therapeutic Applications

• Mycobacterial P27:

  • Recognized by sera from M. bovis-infected cattle, making it a candidate for TB diagnostics .

  • PCR primers specific to P27 gene distinguish M. tuberculosis complex from non-tuberculous mycobacteria .

• Anti-CD27 agonists: Fc-engineered IgG1/IgG2 antibodies enhance CD27 clustering, boosting anti-tumor efficacy in lymphoma models .

Epitope Specificity

• CD27 antibodies: Stronger agonism occurs when antibodies bind membrane-distal, external-facing epitopes (e.g., CRD1 domain) .

• Mycobacterial P27: Antibodies target a conserved lipoprotein signal peptide (ATVVAGC motif) .

Fc Engineering for Enhanced Efficacy

• Suboptimal epitope binding in CD27 antibodies can be overcome using:

  • hIgG2 isotypes: Promote FcγRIIb-mediated receptor clustering .

  • Fc mutations: Enhance binding to inhibitory FcγRIIb .

Table 2: Vaccine Candidates Utilizing 27 kDa Antibodies/Antigens

Challenges and Future Directions

• HIV scFv-VRC01: Requires refolding for functional conformation, limiting scalability .

• Mycobacterial P27: Cross-reactivity with non-tuberculous mycobacteria remains a diagnostic hurdle .

• Anti-CD27 antibodies: Clinical responses are modest compared to preclinical models, necessitating improved Fc engineering .