Project description:Previous research on adaptive NK cells in rhesus macaques suffered from the lack of specific antibodies to differentiate between inhibitory CD94/NKG2A and stimulatory CD94/NKG2C heterodimeric receptors. Recently we reported an expansion of NKG2C receptor-encoding genes in rhesus macaques, but their expression and functional role on primary NK cells remained unknown due to this deficit. Thus, we established monoclonal antibodies 4A8 and 7B1 which show identical specificities and bind to both NKG2C-1 and NKG2C-2 but neither react with NKG2C-3 nor NKG2A on transfected cell lines. Using a combination of 4A8 and Z199 antibodies in multicolor flow cytometry we detected broad expression (4-73%) of NKG2C-1 and/or NKG2C-2 (NKG2C-1/2) on primary NK cells in rhesus macaques from our breeding colony. Stratifying our data to CMV-positive and CMV-negative animals, we noticed a higher proportion (23-73%) in primary NK cells expressing NKG2C-1/2 in CMV+ as compared to CMV- macaques (4-5%). These NKG2C-1/2-positive NK cells in CMV+ macaques are characterized by lower expression of IL12RB2, ZBTB16 and SH2D1B as well as high expression of IFN-gamma, indicating that antibody 4A8 detects CMV-associated adaptive NK cells. Single cell RNA seq data of 4A8-positive NK cells from a CMV-positive individual demonstrated that a high proportion of these adaptive NK cells transcribe in addition to NKG2C-1/2 also NKG2C-3, but interestingly NKG2A as well. Remarkably, NKG2C-1 and in particular NKG2C-2 have a higher affinity to Mamu-E as compared to NKG2A. Primary NK cells exposed to Mamu-E-expressing target cells displayed strong degranulation as well as IFN-gamma expression of 4A8+ adaptive NK cells of rhCMV+ animals that was not evident in rhCMV- animals. Thus, despite co-expression of inhibitory and stimulatory CD94/NKG2 receptors the higher number of different stimulatory NKG2C receptors and their higher binding avidity to Mamu-E outreach inhibitory signaling via NKG2A. These data demonstrate the evolutionary conservation of the CMV-driven development of NKG2C-positive adaptive NK cells with particular molecular signatures in primates and with changes in gene copy numbers and regulation and in ligand binding strength of NKG2C isotypes. Thus, rhesus macaques represent a suitable and valuable nonhuman primate animal model to study the CMV-NKG2C liaison in vivo.
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.
Project description:As humans age their memory T cell compartment expands due to lifelong exposure to antigens. This expansion is characterized by the presence of terminally differentiated CD8+ T cells (Temra) which possess an NK cell-like phenotype and are associated with chronic inflammatory conditions. Temra cells are predominantly driven by sporadic cytomegalovirus reactivation (CMV) yet their cellular heterogeneity remains understudied. To address this gap we measured their gene expression profiles and conducted single-cell transcriptome analysis. We show that CD8+ Temra cells are highly heterogeneous and describe subsets specific to old age and CMV infection.
Project description:As humans age, their memory T cell compartment expands due to the lifelong exposure to antigens. This expansion is characterized by the presence of terminally differentiated CD8+ T cells (Temra), which possess NK cell-like phenotype and are associated with chronic inflammatory conditions. Temra cells are predominantly driven by the sporadic reactivation of cytomegalovirus (CMV), yet their epigenomic patterns and cellular heterogeneity remain understudied. To address this gap, we correlated their gene expression profiles with chromatin openness and conducted single-cell transcriptome analysis, comparing them to other CD8+ subsets and CMV-responses.
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:Constitutively found at high frequencies, the role for NK cell proliferation remains unclear. Here, a shift in NK cell function from predominantly producing interferon-? (IFN-?), a cytokine with proinflammatory and antimicrobial functions, to producing the immunoregulatory cytokine IL-10, is defined during extended murine cytomegalovirus infection. The NK cells driven to express IL-10 in vivo acquired responsiveness to IL-12 and IL-21 for IL-10 production, but neither cytokine was required for the endogenous response. In vitro studies with IL-2 to support proliferation and in vivo adoptive transfers into murine cytomegalovirus-infected mice demonstrated that NK cell proliferation and further division enhanced the change. During infection, the responding NK cells acquired histone modifications indicative of an open IL-10 gene, and an IL-10 response was proliferation dependent ex vivo if the NK cells had not yet expanded in vivo but independent if they had. Thus, a novel role for proliferation in supporting changing innate cell function is discovered. The chromatin status of ex vivo isolated NK cells during MCMV infection was investigated by ChIP-seq on histone epigenetic marks (H3K4m3, H3K27m3, H3K36m3) on day 0, day 1.5 and day 3.5 post infection.
Project description:Human Natural Killer (NK) cells in peripheral blood perform many functions and classification of specific subsets has been a long-standing goal. Here, we report single cell RNA-sequencing of NK cells, comparing gene expression in unstimulated and IL-2 activated cells, from healthy CMV-negative donors. Three NK cell subsets resembled well-described populations, CD56brightCD16-, CD56dimCD16+CD57- and CD56dimCD16+CD57+. CD56dimCD16+CD57- cells sub-divided to include a population with higher chemokine mRNA and increased frequency of KIR expression. Three novel human blood NK cell populations were identified as: a population of type I interferon responding NK cells which were CD56neg, a population exhibiting a cytokine-induced memory-like phenotype, including increased granzyme B mRNA in response to IL-2, and finally, a small population, with low ribosomal expression, down-regulation of oxidative phosphorylation and high levels of immediate early response genes indicative of cellular activation. Analysis of CMV-positive donors established that CMV altered the proportion of NK cells in each subset, especially an increase in adaptive NK cells, as well as gene regulation within each subset. Together, these data establish an unexpected diversity in blood NK cells and provide a new framework for analysing NK cell responses in health and disease.