Anti–PD-1 chimeric antigen receptor T cells efficiently target SIV-infected CD4+ T cells in germinal centers
Karsten Eichholz, … , Afam A. Okoye, Lawrence Corey
Karsten Eichholz, … , Afam A. Okoye, Lawrence Corey
Published April 1, 2024
Citation Information: J Clin Invest. 2024;134(7):e169309. https://doi.org/10.1172/JCI169309.
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Research Article AIDS/HIV

Anti–PD-1 chimeric antigen receptor T cells efficiently target SIV-infected CD4+ T cells in germinal centers

Abstract

Programmed cell death protein 1 (PD-1) is an immune checkpoint marker commonly expressed on memory T cells and enriched in latently HIV-infected CD4+ T cells. We engineered an anti–PD-1 chimeric antigen receptor (CAR) to assess the impact of PD-1 depletion on viral reservoirs and rebound dynamics in SIVmac239–infected rhesus macaques (RMs). Adoptive transfer of anti–PD-1 CAR T cells was done in 2 SIV-naive and 4 SIV-infected RMs on antiretroviral therapy (ART). In 3 of 6 RMs, anti–PD-1 CAR T cells expanded and persisted for up to 100 days concomitant with the depletion of PD-1+ memory T cells in blood and tissues, including lymph node CD4+ follicular helper T (TFH) cells. Loss of TFH cells was associated with depletion of detectable SIV RNA from the germinal center (GC). However, following CAR T infusion and ART interruption, there was a marked increase in SIV replication in extrafollicular portions of lymph nodes, a 2-log higher plasma viremia relative to controls, and accelerated disease progression associated with the depletion of CD8+ memory T cells. These data indicate anti–PD-1 CAR T cells depleted PD-1+ T cells, including GC TFH cells, and eradicated SIV from this immunological sanctuary.

Authors

Karsten Eichholz, Yoshinori Fukazawa, Christopher W. Peterson, Francoise Haeseleer, Manuel Medina, Shelby Hoffmeister, Derick M. Duell, Benjamin D. Varco-Merth, Sandra Dross, Haesun Park, Caralyn S. Labriola, Michael K. Axthelm, Robert D. Murnane, Jeremy V. Smedley, Lei Jin, Jiaxin Gong, Blake J. Rust, Deborah H. Fuller, Hans-Peter Kiem, Louis J. Picker, Afam A. Okoye, Lawrence Corey

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Figure 1

Primary anti–PD-1 CAR T cells do not express PD-1 and kill PD-1–expressing cells.

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Primary anti–PD-1 CAR T cells do not express PD-1 and kill PD-1–expressi...
RM CD8+ T cells transduced with the 6 anti–PD-1 CAR and analyzed by flow cytometry express EGFRt as a surrogate marker for the CAR (A). Gating on EGFRt+ and EGFRt– cells in the culture revealed a loss of PD-1 expression on CAR T and bystander cells in CAR T cells in comparison with nontransduced T cells (B). PD-1+ target cells were generated by transduction of K562 cells with a PD-1 GFP fusion protein–expressing lentivirus followed by sorting for different levels of PD-1 cell-surface expression. PD-1 cell–surface expression was quantified with Quantibrite beads and anti–PD-1 antibody EH12 2H7 (C). Anti–PD-1 CAR T cells kill PD-1+ target cells. Primary anti–PD-1 CAR CD8+ T cells or nontransduced CD8+ T cells were cocultured with K562 PD1 GFP with low, medium, and high PD-1 expression or K562-GFP control target cells at a 1:1 ratio. Cytotoxicity was measured by reduction of GFP+ cells using the IncuCyte Live-Cell Imaging System. Average cytotoxicity ± SEM of 1 representative experiment is shown (n = 3). Statistics were analyzed using 2-way ANOVA with Tukey’s multiple-comparisons test at each time point. Results for 72 hours are reported. ****P < 0.0001 (D).