Development and Application of Broad-Spectrum Detection Monoclonal Antibodies Against HIV-1 P24 Antigen

Objective To enhance the accuracy and coverage of early HIV diagnosis, this study aimed to develop anti-p24 monoclonal antibodies with broad-spectrum recognition capability.Methods Mice were immunized subcutaneously with multi-subtype recombinant HIV-1 P24 antigens. Hybridoma technology was employed to screen and produce P24-specific mAbs. Cross-reactivity was evaluated using a double-antibody sandwich chemiluminescence immunoassay against recombinant P24 proteins and viral lysates from 10 common HIV-1 genotypes, including subtypes A, B, C, D, and CRF01_AE. The affinity of coated antibodies was measured by surface plasmon resonance (SPR). A saturation mutagenesis library targeting key antigen-binding pockets of the coated antibody was constructed. Phage display technology was used to screen the library and enrich high-affinity mutants.Results Three positive hybridoma clones stably secreting antibodies were obtained, all demonstrating strong binding activity against all 10 tested HIV-1 genotypes. The affinity-matured mutant M295# exhibited a dissociation constant (KD) of 1.16×10⁻¹¹ M for subtype B P24 antigen, representing an approximately 40-fold improvement compared to the parental antibody. The limit of detection (LOD) for the WHO international P24 standard antigen decreased from 0.76 IU/mL to 0.66 IU/mL. The detection rate across 10 HIV-1 genotypes reached 59.69%, outperforming commercial assays from Abbott (56.59%), Roche (40.31%), Snibe (13.95%), and Mindray (36.43%). Furthermore, the detection results in clinically suspected HIV-infected patients were fully consistent with nucleic acid test results.Conclusion A panel of monoclonal antibodies capable of efficiently recognizing P24 antigens across diverse HIV-1 subtypes was successfully developed. These antibodies provide superior core materials for constructing highly sensitive detection systems and lay a foundation for more reliable HIV diagnostic reagents.