In-house ELISA protocols for capsid p24 detection of diverse HIV isolates

Virol J. 2023 Nov 17;20(1):269. doi: 10.1186/s12985-023-02242-5.

Abstract

Background: The capsid p24 (CA-p24) antigen is a component of the viral capsid of human immunodeficiency virus (HIV) that has been commonly used for clinical diagnosis and monitoring of HIV infections in Enzyme-linked Immunosorbent Assays (ELISAs). Commercial CA-p24 ELISAs are widely used in research settings, but these kits are costly and have limited breadth for detecting diverse HIV isolates.

Methods: Commercial CA-p24 antibodies were used as capture and detection antibodies. Specific CA-p24 ELISAs were established with these antibodies and tested for the detection of HIV-1 isolates with the aim of developing in-house protocols to recognize HIV-1 infections in vitro for research purposes.

Results: Here we present four protocols for in-house ELISAs to detect HIV CA-p24 using commercial antibodies. The assays were able to detect the CA-p24 antigen of different HIV-1 isolates tested. Comparison between the protocols showed that these in-house ELISAs exhibit high specificity, sensitivity, and reproducibility for CA-p24 quantitation but their reactivity varied per HIV-1 isolate and subtype.

Conclusions: These optimized ELISA protocols represent valuable tools to investigate HIV-1 infections in research facilities at a lower price than commercial CA-p24 kits.

Keywords: Antibodies; Antigen; CA-p24; ELISA; HIV.

MeSH terms

  • Capsid / chemistry
  • Capsid Proteins
  • Enzyme-Linked Immunosorbent Assay / methods
  • HIV Core Protein p24 / analysis
  • HIV Infections*
  • HIV-1*
  • Humans
  • Reproducibility of Results
  • Sensitivity and Specificity

Substances

  • HIV Core Protein p24
  • Capsid Proteins