Cross-Subtype Detection of HIV-1 Capsid p24 Antigen Using a Sensitive Europium Nanoparticle Assay

Area of Science:

• Immunology
• Virology
• Biotechnology

Background:

• Accurate and early detection of diverse Human Immunodeficiency Virus type 1 (HIV-1) subtypes remains a significant challenge.
• Current p24 antigen assays often struggle with cross-subtype reactivity and sensitivity.

Purpose of the Study:

• To develop a sensitive assay for the cross-subtype detection of HIV-1 p24 antigen.
• To identify broadly cross-reactive antibodies for improved Human Immunodeficiency Virus (HIV) detection.

Main Methods:

• Development of a time-resolved fluorescence (TRF) europium nanoparticle immunoassay.
• Screening of multiple antibodies for optimal reactivity with diverse HIV-1 subtypes and circulating recombinant forms.
• Testing assay sensitivity and quantification at picogram per milliliter levels with various HIV strains.

Main Results:

• Identified two broadly cross-reactive HIV-1 p24 antibodies, C65690M and ANT-152, capable of detecting all tested HIV strains.
• The developed assay demonstrated superior signal-to-cutoff ratios compared to a commercial assay.
• Achieved picogram per milliliter level sensitivity for p24 antigen detection.

Conclusions:

• A novel, highly sensitive TRF-based europium nanoparticle immunoassay utilizing specific p24 antibodies can detect all HIV subtypes.
• This assay holds potential for earlier and more accurate Human Immunodeficiency Virus (HIV) detection across diverse global populations.