Decoupling HIV-1 antiretroviral drug inhibition from plasma antibody activity to evaluate broadly neutralizing antibody therapeutics and vaccines. Cell Reports Medicine
On behalf of the Swiss HIV Cohort Study (SHCS), Schwarzmüller et al. developed and validated ART-DEX, a novel high-throughput method to separate antiretroviral drugs (ARVs) from plasma of people with HIV (PWH). This method enables accurate measurement of antibody-mediated HIV-1 neutralization despite the presence of ARVs, an essential requirement for the evaluation of broadly neutralizing antibodies (bnAbs) in therapeutic studies.
The authors systematically compared multiple strategies:
1. The use of ART-resistant HIV pseudoviruses.
2. The use of VSV-based pseudoviruses, insensitive to ARVs.
3. The separation of antibodies using protein A/G beads.
4. The novel ART-DEX method, combining pH-triggered drug dissociation with size exclusion.
They tested these strategies on plasma samples from 563 ART-treated individuals of the SHCS and the Zurich Primary HIV Infection Study. The combination of ART-DEX with an ART-resistant HIV pseudovirus (HIVpv-MDR13) completely eliminated ART interference and allowed reliable measurement of antibody-mediated neutralization activity. The method was validated against standard TZM-bl neutralization assays and showed high accuracy without significant loss of antibody activity.
In conclusion, the authors established a powerful and scalable tool to enable precise monitoring of bnAb activity in plasma samples from ART-treated individuals. This technique is expected to advance both therapeutic bnAb evaluation and HIV cure.