IL-21 and IFN\u03b1 therapy rescues terminally\xa0differentiated NK cells and limits SIV reservoir in ART-treated macaques

Justin Harper,Michaela Müller-Trutwin,Neeta Shenvi,Jeffrey Lifson,Hong Wang,Philippe Rascle,Beatrice Jacquelin,Colin King,Steven Bosinger,Nicolas Huot,Cristin Galardi,Kirk Easley,Francois Villinger,Gregory Tharp,Luca Micci,Amit A Upadhyay,Mirko Paiardini,Guido Silvestri

doi:10.1038/s41467-021-23189-7

Abstract

Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy, nonpathogenic infections in natural hosts, such African green monkeys, are characterized by a lack of gut microbial translocation and robust secondary lymphoid natural killer cell responses resulting in an absence of chronic inflammation and limited SIV dissemination in lymph node B-cell follicles. Here we report, using the pathogenic model of antiretroviral therapy-treated, SIV-infected rhesus macaques that sequential interleukin-21 and interferon alpha therapy generate terminally differentiated blood natural killer cells (NKG2a/clowCD16+) with potent human leukocyte antigen-E-restricted activity in response to SIV envelope peptides. This is in contrast to control macaques, where less differentiated, interferon gamma-producing natural killer cells predominate. The frequency and activity of terminally differentiated NKG2a/clowCD16+ natural killer cells correlates with a reduction of replication-competent SIV in lymph node during antiretroviral therapy and time to viral rebound following analytical treatment interruption. These data demonstrate that African green monkey-like natural killer cell differentiation profiles can be rescued in rhesus macaques to promote viral clearance in tissues.

Highlights

Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy, nonpathogenic infections in natural hosts, such African green monkeys, are characterized by a lack of gut microbial translocation and robust secondary lymphoid natural killer cell responses resulting in an absence of chronic inflammation and limited SIV dissemination in lymph node Bcell follicles
The dashed horizontal line represents the assay’s limit of detection (30 copies/mL) with undetectable events plotted as copies/mL. d The frequency of immune activation (HLA-DR+CD38+) was quantified in memory (CD95+) CD4+ T-cells in PBMCs and e representative flow cytometry plots are given at critical time points for a cytokine-treated (RQm14) and control rhesus macaques (RMs) (RSp14; of 260 single-replicate stains). f The expression of IFN-stimulated genes (ISGs) was measured by RNA-seq in PBMCs at 2 h post-rhesus IFNα-IgFc (rIFNα) and was calculated as a log[2] fold-change between rIFNα-treated (n = 6) and control RMs (n = 5), which is represented as a double-gradient heatmap
The SIV-Env-specific, human leukocyte antigen (HLA)-E-restricted activity was calculated as the log10-transformed percent yield of CD107a surface expression on N atural killer (NK) cells by flow cytometry and the horizontal dashed line represents 100% activity. b–d, g–i Treatment phases are indicated with the following background shading: IL-21, rIFNα, and antiretroviral therapy (ART). d, g–i Data from individual RMs are overlaid against the mean ± SEM: control and cytokine-treated

Summary

Introduction

Unlike HIV infection, which progresses to AIDS absent suppressive anti-retroviral therapy, nonpathogenic infections in natural hosts, such African green monkeys, are characterized by a lack of gut microbial translocation and robust secondary lymphoid natural killer cell responses resulting in an absence of chronic inflammation and limited SIV dissemination in lymph node Bcell follicles. We report, using the pathogenic model of antiretroviral therapy-treated, SIVinfected rhesus macaques that sequential interleukin-21 and interferon alpha therapy generate terminally differentiated blood natural killer cells (NKG2a/clowCD16+) with potent human leukocyte antigen-E-restricted activity in response to SIV envelope peptides. This is in contrast to control macaques, where less differentiated, interferon gamma-producing natural killer cells predominate. The frequency and activity of terminally differentiated NKG2a/clowCD16+ natural killer cells correlates with a reduction of replication-competent SIV in lymph node during antiretroviral therapy and time to viral rebound following analytical treatment interruption These data demonstrate that African green monkey-like natural killer cell differentiation profiles can be rescued in rhesus macaques to promote viral clearance in tissues. SIV infection, we sought to determine whether immunotherapy with IL-21 and IFNα rescues AGM-like profiles of NK cell maturation and activity in SIV-infected rhesus macaques (RMs)

Methods

Results

Conclusion