Project description:In order to gain a better understanding of gene expression during early malaria infection, we conducted microarray analysis of early blood responses in mice infected with erythrocytic stage Plasmodium chabaudi. Immediately following infection, we observed coordinated and sequential waves of immune responses, with interferon-associated gene transcripts dominating by 16 hours post-infection, followed by strong increases in natural killer (NK) cell-associated and MHC class I-related transcripts by 32 hours post-infection. We hypothesized that the observed elevation in NK cell-associated transcripts could be the result of a dramatic increase in the proportion of NK cells in the blood during infection, which we confirmed by flow cytometry. Subsequent microarray analysis of NK cells isolated from the peripheral blood of infected mice revealed a cell proliferation expression signature consistent with the observation that NK cells replicate in response to infection. Early proliferation of NK cells was directly observed in studies with adoptively transferred cells in infected mice. These data indicate that the early response to P. chabaudi infection of the blood is marked by a primary wave of interferon with a subsequent response by NK cells. Keywords: murine NK cell response to Plasmodium chabaudi infection We analyzed a series of 10 MEEBO arrays on which were hybed RNA amplified from NK cells of C57BL/6 mice either mock-infected or infected with P. chabaudi AS.
Project description:In order to gain a better understanding of gene expression during early malaria infection, we conducted microarray analysis of early blood responses in mice infected with erythrocytic stage Plasmodium chabaudi. Immediately following infection, we observed coordinated and sequential waves of immune responses, with interferon-associated gene transcripts dominating by 16 hours post-infection, followed by strong increases in natural killer (NK) cell-associated and MHC class I-related transcripts by 32 hours post-infection. We hypothesized that the observed elevation in NK cell-associated transcripts could be the result of a dramatic increase in the proportion of NK cells in the blood during infection, which we confirmed by flow cytometry. Subsequent microarray analysis of NK cells isolated from the peripheral blood of infected mice revealed a cell proliferation expression signature consistent with the observation that NK cells replicate in response to infection. Early proliferation of NK cells was directly observed in studies with adoptively transferred cells in infected mice. These data indicate that the early response to P. chabaudi infection of the blood is marked by a primary wave of interferon with a subsequent response by NK cells. Keywords: murine whole blood response to Plasmodium chabaudi infection We analyzed a series of 36 MEEBO arrays on which were hybed RNA amplified from whole blood of C57BL/6 mice either mock-infected or infected with P. chabaudi AS.
Project description:Natural Killer (NK) cells likely play an important role in immunity to malaria, but whether repeated malaria modifies the NK cell response remains unclear. Here, we comprehensively profiled the NK cell response in a cohort of 264 Ugandan children. Repeated malaria exposure was associated with expansion of an atypical, CD56neg population of NK cells that differed transcriptionally, epigenetically, and phenotypically from CD56dim NK cells, including decreased expression of PLZF and the Fc receptor g chain, increased histone methylation, and increased protein expression of LAG-3, KIR and LILRB1. CD56neg NK cells were highly functional, displaying greater antibody dependent cellular cytotoxicity than CD56dim NK cells, and higher frequencies of these cells were associated with protection against symptomatic malaria and high parasite densities. Importantly, following marked reductions in malaria transmission, frequencies of these cells rapidly declined, suggesting that continuous exposure to malaria is required to maintain this modified, adaptive-like NK cell subset.
Project description:In order to gain a better understanding of gene expression during early malaria infection, we conducted microarray analysis of early blood responses in mice infected with erythrocytic stage Plasmodium chabaudi. Immediately following infection, we observed coordinated and sequential waves of immune responses, with interferon-associated gene transcripts dominating by 16 hours post-infection, followed by strong increases in natural killer (NK) cell-associated and MHC class I-related transcripts by 32 hours post-infection. We hypothesized that the observed elevation in NK cell-associated transcripts could be the result of a dramatic increase in the proportion of NK cells in the blood during infection, which we confirmed by flow cytometry. Subsequent microarray analysis of NK cells isolated from the peripheral blood of infected mice revealed a cell proliferation expression signature consistent with the observation that NK cells replicate in response to infection. Early proliferation of NK cells was directly observed in studies with adoptively transferred cells in infected mice. These data indicate that the early response to P. chabaudi infection of the blood is marked by a primary wave of interferon with a subsequent response by NK cells. Keywords: murine NK cell response to Plasmodium chabaudi infection
Project description:In order to gain a better understanding of gene expression during early malaria infection, we conducted microarray analysis of early blood responses in mice infected with erythrocytic stage Plasmodium chabaudi. Immediately following infection, we observed coordinated and sequential waves of immune responses, with interferon-associated gene transcripts dominating by 16 hours post-infection, followed by strong increases in natural killer (NK) cell-associated and MHC class I-related transcripts by 32 hours post-infection. We hypothesized that the observed elevation in NK cell-associated transcripts could be the result of a dramatic increase in the proportion of NK cells in the blood during infection, which we confirmed by flow cytometry. Subsequent microarray analysis of NK cells isolated from the peripheral blood of infected mice revealed a cell proliferation expression signature consistent with the observation that NK cells replicate in response to infection. Early proliferation of NK cells was directly observed in studies with adoptively transferred cells in infected mice. These data indicate that the early response to P. chabaudi infection of the blood is marked by a primary wave of interferon with a subsequent response by NK cells. Keywords: murine whole blood response to Plasmodium chabaudi infection
Project description:Natural Killer cells (NK), a major constituent of innate immune system, have the ability to kill the transformed and infected cells without prior sensitization; can be put to immunotherapeutic use against various malignancies. NK cells discriminate between normal cells and transformed cells via a balance of inhibitory and activating signals induced by interactions between NK cell receptors and target cell ligands. Present study investigates whether expansion of NK cells could augment their anti-myeloma (MM) activity. For NK cell expansion, peripheral blood mononuclear cells from healthy donors and myeloma patients were co-cultured with irradiated K562 cells transfected with 4-1BBL and membrane-bound IL15 (K562-mb15-41BBL). A genome-wide profiling approach was performed to identify gene expression signature in expanded NK (ENK) cells and non-expanded NK cells isolated from healthy donors and myeloma patients. A specific set of genes involved in proliferation, migration, adhesion, cytotoxicity, and activation were up regulated post expansion, also confirmed by flow cytometry. Exp-NK cells killed both allogeneic and autologous primary MM cells more avidly than non-exp-NK cells in vitro. Multiple receptors, particularly NKG2D, natural cytotoxicity receptors, and DNAM-1 contributed to target lysis, via a perforin mediated mechanism. In summary, vigorous expansion and high anti-MM activity both in vitro and in vivo provide the rationale for testing exp-NK cells in a clinical trial for high risk MM. Differential gene expression profile in expanded natural killer (ENK) cells and non-expanded natural killer (NK) cells from healthy donors and myeloma patients Eight healthy donor and eight myeloma patients were used in the study. Non-expanded natural killer (NK) cells were isolated from PBMCs of healthy donors and myeloma patients. Expanded natural killer (ENK) cells were generated from same set of samples as mentioned in expansion protocol. All ENK and NK cells were used for gene expression profiling.
Project description:Natural Killer (NK) cells and CD8+ T cells share many characteristics at steady state and during viral infection. In this study, we interrogate the metabolic pathways that fuel NK cell effector function in response to mouse cytomegalovirus (MCMV) infection. This dataset contains transcriptional profiling of wild-type and LDHA-deficient Ly49Hpositive NK cells at steady state and early after infection.
Project description:Natural killer (NK) cells are innate lymphocytes with the capacity to elicit adaptive features, including clonal expansion and immunological memory. Because signal transducer and activator of transcription 5 (STAT5) is essential for NK cell development, the role of this transcription factor and its upstream cytokines IL-2 and IL-15 during infection have not been carefully investigated. In this study, we investigate how STAT5 regulates transcription during viral infection. We demonstrate that STAT5 is induced in NK cells by IL-12 and STAT4 early after infection, and that partial STAT5 deficiency results in a defective capacity of NK cells to generate long-lived memory cells. Furthermore, we find a functional dichotomy of IL-2 and IL-15 signaling outputs during viral infection, whereby both cytokines drive clonal expansion, but only IL-15 is required for memory NK cell survival. We thus highlight a novel role for STAT5 signaling in promoting an optimal antiviral NK cell response.
Project description:Natural killer (NK) cells are innate lymphocytes that possess features of adaptive immunity, such as the ability to recognize specific antigen, among others. In MCMV infection, the engagement of a subset of NK cells expressing an activating receptor Ly49H with MCMV-derived glycoprotein m157 results in a clonal-like expansion and the generation of a small pool of long-lived memory cells with higher Ly49H expression than the naive Ly49H-expressing NK cell pool. In this study, we interrogate the transcriptional differences between NK cells that express high verus low levels of Ly49H early after infection.