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Updated: Jun 26, 2025
Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays
Published on: March 14, 2011
Defining the Effects of PKC Modulator HIV Latency-Reversing Agents on Natural Killer Cells
Melanie Dimapasoc1,2, Jose A Moran3, Steve W Cole4
1Molecular Biology Institute, University of California Los Angeles, Los Angeles, California.
Background:
Latency reversing agents (LRAs) such as protein kinase C (PKC) modulators can reduce rebound-competent HIV reservoirs in small animal models. Furthermore, administration of natural killer (NK) cells following LRA treatment improves this reservoir reduction. It is currently unknown why the combination of a PKC modulator and NK cells is so potent and whether exposure to PKC modulators may augment NK cell function in some way.
Methods:
Primary human NK cells were treated with PKC modulators (bryostatin-1, prostratin, or the designed, synthetic bryostatin-1 analog SUW133), and evaluated by examining expression of activation markers by flow cytometry, analyzing transcriptomic profiles by RNA sequencing, measuring cytotoxicity by co-culturing with K562 cells, assessing cytokine production by Luminex assay, and examining the ability of cytokines and secreted factors to independently reverse HIV latency by co-culturing with Jurkat-Latency (J-Lat) cells.
Results:
PKC modulators increased expression of proteins involved in NK cell activation. Transcriptomic profiles from PKC-treated NK cells displayed signatures of cellular activation and enrichment of genes associated with the NFκB pathway. NK cell cytotoxicity was unaffected by prostratin but significantly decreased by bryostatin-1 and SUW133. Cytokines from PKC-stimulated NK cells did not induce latency reversal in J-Lat cell lines.
Conclusions:
Although PKC modulators have some significant effects on NK cells, their contribution in "kick and kill" strategies is likely due to upregulating HIV expression in CD4+ T cells, not directly enhancing the effector functions of NK cells. This suggests that PKC modulators are primarily augmenting the "kick" rather than the "kill" arm of this HIV cure approach.
Insights
Protein kinase C (PKC) modulators boost HIV latency reversal by increasing HIV expression in T cells, not by enhancing natural killer (NK) cell functions. This research clarifies the "kick and kill" strategy for HIV cure.
Area of Science:
- Immunology
- Virology
- Molecular Biology
Background:
- Latency reversing agents (LRAs), including protein kinase C (PKC) modulators, show promise in reducing HIV reservoirs.
- Combining LRAs with natural killer (NK) cells enhances HIV reservoir reduction in preclinical models.
- The precise mechanism by which PKC modulators and NK cells synergize remains unclear.
Purpose of the Study:
- To investigate whether PKC modulators enhance NK cell effector functions.
- To determine the impact of PKC modulators on NK cell activation, cytotoxicity, and cytokine production.
- To assess if secreted factors from PKC-modulated NK cells can reverse HIV latency.
Main Methods:
- Primary human NK cells were treated with PKC modulators (bryostatin-1, prostratin, SUW133).
- NK cell activation markers, transcriptomic profiles (RNA sequencing), cytotoxicity, and cytokine production were analyzed.
- Jurkat-Latency (J-Lat) cells were used to assess the latency-reversing potential of secreted factors.
Main Results:
- PKC modulators increased NK cell activation markers and altered transcriptomic profiles, with NFκB pathway enrichment.
- Cytotoxicity was reduced by bryostatin-1 and SUW133, but not prostratin.
- Cytokines produced by PKC-stimulated NK cells did not induce HIV latency reversal in J-Lat cells.
Conclusions:
- PKC modulators primarily enhance the
- kick
- (upregulating HIV expression) rather than the
- kill
- (NK cell effector function) component of HIV cure strategies.
- The observed synergy in preclinical models is likely due to enhanced viral reactivation in infected cells, not direct augmentation of NK cell activity.
- PKC modulators' role in combination HIV therapy warrants further investigation focusing on their impact on viral reservoirs.
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