Project description:Ly49G2+ NK cells mediate essential control of murine cytomegalovirus (MCMV) infection in mice which express the H-2Dk class I molecule. As a cognate ligand for specific Ly49G2 inhibitory receptor allotypes, H-2Dk also licenses Ly49G2+ NK cells in naïve and MCMV-infected mice. These findings suggest Ly49G2 may promote antiviral NK cell activities during MCMV infection. Indeed, in mice lacking the Ly49G2 receptor, MCMV resistance is fully abrogated. Additionally, NK cells expressing Ly49R, an NK cell associated activation receptor that also recognizes H-2Dk, have their function augmented by Ly49G2 and are required for MCMV resistance.
Project description:Murine Cytomegalovirus (MCMV) infection leads to the activation of various immune cells, including dendritic cells (DCs) and Natural Killer (NK) cells. This activation is partly driven by innate cytokines including IFN-I, which are induced early after infection. The objective was to address the role of different innate cytokines in shaping DC subsets and NK cell responses, in particular the role of cell intrinsic responses to IFN-I. In order to decipher the specific impact of cell-intrinsic IFN-I on cell subsets, we performed a genome-wide expression analysis on CD45.1 WT and CD45.2 IFNAR-/- splenic conventional DC (cDC) subsets and NK cells isolated from C57BL/6 [CD45.1 WT / CD45.2 IFNAR-KO] mixed bone marow chimera mice. This study includes data from cDC subsets (CD8a and CD11b) and NK cells purified by flow cytometry sorting from the spleen of bone marrow chimera (BMC) mice, under steady-state or MCMV condition. Two independent replicates were made for each cell type, from two independent pools of spleens from uninfected or d1.5 MCMV-infected BMC 5-8 mice, and were hybridized on 3 separate batches of gene chips.
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.
Project description:Recent work indicates that salivary glands are able to constitutively recruit CD8+ T cells and retain them as tissue resident memory T cells (TRM), independently of local infection, inflammation or antigen. To understand the mechanisms supporting T cell recruitment to the salivary gland, we compared T cell migration to the salivary gland in mice infected or not with murine cytomegalovirus (MCMV), a herpesvirus that infects the salivary gland and promotes the accumulation of salivary gland TRM. We found that acute MCMV infection increased rapid T cell recruitment to the salivary gland, but that equal numbers of activated CD8+ 44 T cells eventually accumulated in both infected and uninfected glands. T cell recruitment to uninfected salivary glands depended on chemokines and the integrin α4. Several chemokines were expressed in the salivary glands of both infected and uninfected mice and many of these could promote the migration of MCMV-specific T cells in vitro. MCMV infection increased expression of chemokines that interact with the receptors CXCR3 and CCR5, but neither receptor was needed for T cell recruitment to the salivary gland during MCMV infection. Unexpectedly however, the chemokine receptor CXCR3 was critical for T cell accumulation in uninfected salivary glands. Together, these data suggest that CXCR3 and the integrin α4 mediate T cell recruitment to uninfected salivary glands, but that redundant mechanisms mediate T cell recruitment after MCMV infection.
Project description:Dendritic cells (DCs) are a complex group of cells which play a critical role in vertebrate immunity. They are subdivided into conventional DC (cDC) subsets (CD11b and CD8alpha in mouse) and plasmacytoid DCs (pDCs). Natural killer cells are innate lymphocytes involved in the recognition and killing of abnormal self cells, including virally infected cells or tumor cells. DCs and NK cells are activated very early upon viral infections and regulate one another. However, the global responses of DC and NK cells early after viral infection in vivo and their molecular regulation are not entirely characterized. The goal of this experiment was to use global gene expression profiling to assess the global genetic reprogramming of DC and NK cells during a viral infection in vivo, as compared to B lymphocytes, and to investigate the underlying molecular mechanisms This study includes data from cell sort purified DCs, NK cells and B cells isolated from the spleen of MCMV-infected mice. 2 independent replicates were made for each cell type except B cells. The control dataset for cells isolated from uninfected control animals has been previously published and is available in the GEO database as GSE9810. The complete dataset representing: (1) the infected Samples and (2) the uninfected control Samples from Series GSE9810 (re-processed using RMA), is linked below as a supplementary file. Comparison of the gene expression programs of wild-type spleen leukocyte subsets, including plasmacytoid DCs, CD8alpha conventional DCs, CD11b conventional DCs and NK cells, isolated from MCMV-infected versus control animals.
Project description:Murine Cytomegalovirus (MCMV) infection leads to early activation of various immune cells, including B and T lymphocytes, before the actual initiation of antigen-specific adaptive immunity. This activation is partly driven by innate cytokines, including type I interferon (IFN), which are induced early after infection. The objective of this study was to address the role of type I IFN in shaping early/innate B and T cell responses to a primary acute viral infection. In order to decipher the specific impact of IFN-I on cell subsets, we performed a genome-wide expression analysis on WT splenic B and CD8 T lymphocytes isolated from C57BL/6 [CD45.1 WT / CD45.2 IFNAR-KO] mixed bone marrow chimera mice. This study complements series GSE39555, which focused on early responses of NK cells and of the two subsets of conventional dendritic cells. This study includes data from B and CD8 T lymphocytes purified by flow cytometry sorting from the spleen of bone marrow chimera (BMC) mice, under steady-state or MCMV conditions. Two independent replicates were made for each cell type, from two independent pools of spleens from uninfected or d1.5 MCMV-infected BMC 5-8 mice, and were hybridized on 3 separate batches of GeneChips.
Project description:Innate and adaptive immune cells can acquire “memory” of encounters with a diverse range of activating signals to tune their response to secondary stimuli. Group 1 innate lymphoid cells (ILC1) are recently discovered tissue-resident sentinels that are essential for early host protection from intracellular pathogens at initial sites of infection. However, whether ILC1 function as short-lived effectors or persist and refine their responsiveness following pathogen challenge is not well understood. Furthermore, whether pathogen-derived antigens directly modulate tissue-resident ILC responses remains unclear. Here, we found that liver-resident ILC1 expand locally and persist following the resolution of mouse cytomegalovirus (MCMV) infection. MCMVexperienced ILC1 acquired stable transcriptional, epigenetic, and phenotypic changes, with an enhanced protective effector response to secondary MCMV challenge. Protective memory ILC1 responses were dependent on the MCMV-encoded glycoprotein m12, but not formed during bystander cytokine activation following heterologous infection. Thus, liver ILC1 acquire adaptive features in a MCMV-specific manner.
Project description:Prenatal Human Cytomegalovirus (HCMV) infection often causes CNS maldevelopment. In a murine model, we detect Murine Cytomegalovirus (MCMV) in brain following intra-peritoneal inoculation at birth. Infected mice show impaired cerebellar development and impaired neurologic function on a beam balance test as adults. Among developmental genes differentially regulated, hindbrain expression of the homeodomain transcription factor HOXa5 was reduced with infection, and fewer HOXa5 expressing neurons were found in vestibular nuclei. Based on the hypothesis that immune activation connects focal viral infection and global CNS maldevelopment, we defined the components of CNS immune response. Flow cytometry showed a large increase in both number and activation of CNS monocytes. Monocytes were found in close association with infected cells by immunohistochemistry (IHC). Oligonucleotide microarrays contained herein identified many differentially expressed genes related to innate immune response. Chemokines, cytokines, cell surface receptors, and proteases are some of the many immunological genes shown to be differentially regulated by MCMV infection. These results together show that MCMV infection induces a complex immune response associated with changes in developmental gene expression and lasting neurologic defecit. Keywords: disease state comparison (virus infection) and competetive hybridization for expression analysis
Project description:Murine Cytomegalovirus (MCMV) infection leads to the activation of various immune cells, including dendritic cells (DCs) and Natural Killer (NK) cells. This activation is partly driven by innate cytokines including IFN-I, which are induced early after infection. The objective was to address the role of different innate cytokines in shaping DC subsets and NK cell responses, in particular the role of cell intrinsic responses to IFN-I. In order to decipher the specific impact of cell-intrinsic IFN-I on cell subsets, we performed a genome-wide expression analysis on CD45.1 WT and CD45.2 IFNAR-/- splenic conventional DC (cDC) subsets and NK cells isolated from C57BL/6 [CD45.1 WT / CD45.2 IFNAR-KO] mixed bone marow chimera mice.
Project description:One goal of viral infection is to reprogram the host cell to optimize viral replication. As part of this process, viral miRNAs may compete for components of the miRNA/siRNA pathway as well as regulate cellular targets. Mouse Cytomegalovirus has been described to generate large numbers of viral miRNAs during lytic infection and was therefore used to analyze the impact of viral miRNAs on the host cell small RNA system as well as to check for sorting of viral small RNAs into specific Ago-proteins. Deep sequencing analysis of MCMV infected cells revealed that viral miRNAs represent only app. 13% of all detected miRNAs. All previously described MCMV miRNAs with the exception of miR-m88-1* were confirmed and for the MCMV miR-m01-1 hairpin an additional miRNA, designated miR-m01-1-3p, was found. Its presence was confirmed by qPCR and Northern Blot. Deep sequencing after RISC IP with antibodies specific for either Ago1 or Ago2 showed that all MCMV miRNAs are loaded into both RISC complexes. The ratio of MCMV to mouse miRNAs was not increased after immunoprecipitation of Ago-proteins. Viral miRNAs therefore do not overwhelm the host miRNA processing system nor are they preferentially incorporated into RISC. We found that 3 mouse miRNAs showed an altered expression due to MCMV infection. Down-regulation of miR-27a, as previously described, could be confirmed. In addition, miR-26a was down-regulated and an up-regulation of miR-7a dependent on viral protein expression could be observed. Examination of small RNA expression in uninfected vs. infected cells, immunoprecipitation + sequencing of Ago1 and Ago2 loaded small RNAs in infected cells