Project description:NK cells are major innate and adaptive responders to malaria, with multiple roles in protection. Function of NK cells is heterogeneous, underpinned by expression of a diversity of receptors. One driver of NK cell heterogeneity is latent CMV infection, which drives the expansion of memory-like NK cells. We have recently reported that latent CMV infection can negatively impact the adaptive immune response to malaria, but whether CMV-mediated changes to the NK cell compartment also impact responses to malaria is unknown. Methods: We investigated the impact of latent CMV infection on NK cell response to the malaria parasite Plasmodium falciparum in vitro, and in CMV seronegative and seropositive individuals during controlled human malaria infection. We analysed NK cell activation, cytotoxicity and NK cell receptor expression. Additionally, we investigated the impact of CMV serostatus on cytokine production in response to TLR stimulation in the myeloid cell compartment. The impact of CMV and NK cell responses on malaria symptoms and parasite control and symptoms of malaria was investigated. Results: NK cells from CMV seropositive individuals had reduced responsiveness to P. falciparum parasites in vitro and had reduced activation during controlled human infection. Reduced activation was not restricted to NK subsets modulated by CMV but occurred across the entire NK cell compartment. Consistent with global NK cell attenuation, IL-12 production from myeloid cells, a response that supports NK cell activation on exposure to P. falciparum parasites, was lower in CMV infected individuals. Linking NK cell activation to clinical outcomes, NK cells expressing perforin were strongly associated with parasite control in CMV seronegative individuals. Conclusion: CMV infection modulates NK cell responses during malaria by disruption of IL-12, leading to reduced parasite control.
Project description:The mechanisms underlying human natural killer (NK) cell phenotypic and functional heterogeneity are unknown. Here, we have described the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Genome-wide DNA methylation patterns were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector T cells, but differed from those of canonical NK cells. Functional interrogation demonstrated altered cytokine responsiveness in adaptive NK cells that was linked to reduced expression of the transcription factor PLZF. Furthermore, subsets of adaptive NK cells demonstrated significantly reduced functional responses to activated autologous T cells. The present results uncover a spectrum of epigenetically unique adaptive NK cell subsets that diversify in response to viral infection and have distinct functional capabilities compared to canonical NK cell subsets.
2015-03-06 | GSE66563 | GEO
Project description:Epigenetic and transcriptional characterisation of CMV driven diversification of NK cells
Project description:Cytomegalovirus (CMV) infection is ubiquitous; though often unnoticed in healthy adults it is a leading cause of neurodisability in neonates/ infants. NK and CD8 T cell cytolysis control CMV; yet their coordinate response to CMV remains uncharacterized, particularly in infants. We interrogated how NK and CD8 T cell responses differed between adults and infants in a murine CMV (MCMV) infection model. NK and CD8 T cells both limited infant MCMV infection morbidity. Notably, adult and infant NK cells effectuate discrete responses to MCMV infection with the latter preferentially forming memory associated with transcriptional distinctions prior to infection. Adoptive transfer studies further revealed that infant T cells are effector-biased but acquire the capacity to form memory in an age-dependent manner. Infant T cells' restricted ability to form memory was associated with a unique transcriptional state before and after infection. Further, acquisition of T cell memory capacity coincided with an age-dependent waning in the induction of adaptive NK cells. Our data suggests non-redundant roles for NK and CD8 T cells in MCMV infection during infancy, as NK cells compensate for the limited establishment of memory T cell subsets.
Project description:Cytomegalovirus (CMV) infection is ubiquitous; though often unnoticed in healthy adults it is a leading cause of neurodisability in neonates/ infants. NK and CD8 T cell cytolysis control CMV; yet their coordinate response to CMV remains uncharacterized, particularly in infants. We interrogated how NK and CD8 T cell responses differed between adults and infants in a murine CMV (MCMV) infection model. NK and CD8 T cells both limited infant MCMV infection morbidity. Notably, adult and infant NK cells effectuate discrete responses to MCMV infection with the latter preferentially forming memory associated with transcriptional distinctions prior to infection. Adoptive transfer studies further revealed that infant T cells are effector-biased but acquire the capacity to form memory in an age-dependent manner. Infant T cells' restricted ability to form memory was associated with a unique transcriptional state before and after infection. Further, acquisition of T cell memory capacity coincided with an age-dependent waning in the induction of adaptive NK cells. Our data suggests non-redundant roles for NK and CD8 T cells in MCMV infection during infancy, as NK cells compensate for the limited establishment of memory T cell subsets.
Project description:The mechanisms underlying human NK cell phenotypic and functional heterogeneity are unknown. Here, we describe the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Intriguingly, geneome-wide analyses revealed patterns of DNA methylation that were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector CD8+ T cells, but differed from those of canonical NK cells.
Project description:The mechanisms underlying human NK cell phenotypic and functional heterogeneity are unknown. Here, we describe the emergence of diverse subsets of human NK cells selectively lacking expression of signaling proteins following cytomegalovirus (CMV) infection. The absence of B and myeloid cell-related signaling protein expression in these NK cell subsets correlated with promoter DNA hypermethylation. Intriguingly, geneome-wide analyses revealed patterns of DNA methylation that were strikingly similar between CMV-associated adaptive NK cells and cytotoxic effector CD8+ T cells, but differed from those of canonical NK cells. A total of 23 samples were analyzed (4 sorted NK cell subsets and 2 sorted T cell subsets each from 4 individual donors). In one donor only 5 subsets were analyzed. Bisulfite-converted genomic DNA was hybridized to the Illumina Human Methylation450 BeadChip
Project description:Natural killer (NK) cells are circulating lymphocytes that possess both innate and adaptive features, the latter including antigen-specific clonal expansion and long-lived memory responses. Unlike other adaptive lymphocytes like T and B cells, NK cells are not thought to require priming in lymphoid organs during activation. However, although NK cells respond in multiple tissue sites during cytomegalovirus (CMV) infection, here we observed that early activation and virus-specific expansion occurs predominantly in the spleen. These splenic NK cells exhibited heightened TNF-a signaling, which we identify as a novel and critical regulator of both innate and adaptive responses through engagement of distinct NF-kB signaling arms downstream of TNFR2. These findings highlight the central role of the spleen as a lymphoid organ in facilitating the innate-to-adaptive transition NK cells undergo during viral infection, and provide insight into how we can better generate innate and adaptive NK cell immunity across diverse settings. Bulk RNA-Seq data of WT or TNFR2-/- Ly49H+ NK from spleen at different time points post MCMV infection.
Project description:Natural killer (NK) cells are circulating lymphocytes that possess both innate and adaptive features, the latter including antigen-specific clonal expansion and long-lived memory responses. Unlike other adaptive lymphocytes like T and B cells, NK cells are not thought to require priming in lymphoid organs during activation. However, although NK cells respond in multiple tissue sites during cytomegalovirus (CMV) infection, here we observed that early activation and virus-specific expansion occurs predominantly in the spleen. These splenic NK cells exhibited heightened TNF-a signaling, which we identify as a novel and critical regulator of both innate and adaptive responses through engagement of distinct NF-kB signaling arms downstream of TNFR2. These findings highlight the central role of the spleen as a lymphoid organ in facilitating the innate-to-adaptive transition NK cells undergo during viral infection, and provide insight into how we can better generate innate and adaptive NK cell immunity across diverse settings. Bulk RNA-Seq data of WT Ly49H+ NK from spleen or liver on day 0 and day 1 post MCMV infection.
Project description:Epigenetic landscapes can provide insight into regulation of gene expression and cellular diversity. Here, we examined the transcriptional and epigenetic profiles of seven human blood NK cell populations, including adaptive NK cells. The BCL11B gene, encoding a transcription factor (TF) essential for T cell development and function, was the most extensively regulated, with expression increasing throughout NK cell differentiation. Several Bcl11b-regulated genes associated with T cell-signaling were specifically expressed in adaptive NK cell subsets. Regulatory networks revealed reciprocal regulation at distinct stages of NK cell differentiation, with Bcl11b repressing RUNX2 and ZBTB16 in canonical and adaptive NK cells, respectively. A critical role for Bcl11b in driving NK cell differentiation was corroborated in BCL11B mutated patients and by ectopic Bcl11b expression. Moreover, Bcl11b was required for adaptive NK cell responses in a murine CMV model, supporting expansion of these cells. Together, we define the TF regulatory circuitry of human NK cells and uncover a critical role for Bcl11b in promoting NK cell differentiation and function.