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1.  Regulatory T cells and Th17 cells in viral infections: implications for multiple sclerosis and myocarditis 
Future virology  2012;7(6):593-608.
In immune-mediated diseases, Treg and proinflammatory Th17 cells have been suggested to play either suppressor (beneficial) or effector (detrimental) roles, respectively. Tissue damage in viral infections can be caused by direct viral replication or immunopathology. Viral replication can be enhanced by anti-inflammatory responses and suppressed by proinflammatory responses. However, Tregs could suppress proinflammatory responses, reducing immunopathology, while Th17 cell-induced inflammation may enhance immunopathology. Here, the roles of Treg and Th17 cells depend on whether tissue damage is caused by direct virus replication or immunopathology, which differ depending on the virus, disease stage and host immune background. Although the precise mechanisms of tissue damage in multiple sclerosis and myocarditis are unclear, both viral replication and immune effector cells have been proposed to cause pathogenesis. Personalized medicine that alters the balance between Treg and Th17 cells may ameliorate viral pathology during infections.
PMCID: PMC3457923  PMID: 23024699
autoimmunity; Cardiovirus infections; CNS demyelinating disease; coinfection; experimental nervous system autoimmune disease; immunology; inflammation; Picornaviridae infections; regulatory T-lymphocyte; Th17 cells
2.  Alcohol Affects the Late Differentiation of Progenitor B Cells 
Aims: Previous studies show that alcohol exposure can affect the differentiation of progenitor B cells. Before final commitment to a B lineage, progenitor B cells usually undergo several important stages. However, it is still unclear whether alcohol alters B cell differentiation at which stages. The aim of this study was to determine which stage(s) of progenitor cell differentiation are affected by alcohol and to elucidate the mechanism(s) responsible for the effect of alcohol on B cell differentiation. Methods: Oligoclonal-neonatal-progenitor (ONP) cells from bone marrow cells of 2-week-old mice were cultured under different conditions in vitro with or without the exposure of 100 mM alcohol. Phenotype analysis was performed at different time points and expression levels of transcription factors (TFs) and cytokine receptors were measured quantitatively and kinetically. Results: After 3 days in vitro culture, ONP cells differentiated into two populations: B220−CD11b− and B220−CD11b+ cells. B220−CD11b− cells can further differentiate into B lineage cells only with the support of B220−CD11b+ cells. Cells exposed to 100 mM of alcohol during the first 3 days of culture showed no statistically significant difference in B cell formation after 12 days compared with the control group. However, cells exposed to alcohol from Day 4 till the end of culture yield very few B cells. Expression levels of TFs and cytokine receptors were down-regulated kinetically among ONP cells co-cultured with the addition of 100 mM alcohol. Conclusions: Alcohol affects the ONP cell differentiation into B lineage at a late stage. Alcohol also down-regulates the expression level of TFs and cytokine receptors resulting in the impairment of B cell differentiation.
PMCID: PMC3002845  PMID: 21098503
3.  Ethanol exhibits specificity in its effects on differentiation of hematopoietic progenitors1 
Cellular immunology  2008;255(1-2):1-7.
Ethanol is a known teratogen but the mechanisms by which this simple compound affects fetal development remain unresolved. The goal of the current study was to determine the mechanism by which ethanol affects lymphoid differentiation using an in vitro model of ethanol exposure. Primitive hematopoietic oligoclonal neonatal progenitor cells (ONP), with the phenotype Lin−HSAloCD43loSca-1−c-Kit+ that are present in neonatal but not adult bone marrow were sorted from the bone marrow of 2-week-old C57BL/6J mice and cultured under conditions that favor either B cell or myeloid cell differentiation with or without addition of ethanol. The overall growth of the ONP cells was not significantly affected by inclusion of up to 100mM ethanol in the culture medium. However, the differentiation of the progenitor cells along the B-cell pathway was significantly impaired by ethanol in a dose dependent manner. Exposure of ONP cells to 100mM ethanol resulted in greater than 95% inhibition of B cell differentiation. Conversely, ethanol concentrations up to and including 100mM had no significant effect on differentiation along the myeloid pathway. The effect of ethanol on transcription factor expression was consistent with the effects on differentiation. ONP cells grown in 100mM ethanol failed to up-regulate Pax5 and EBF, transcriptional regulators that are necessary for B cell development. However, ethanol had no significant effect on the up-regulation of PU.1, a transcription factor that, when expressed in high concentration, favors myeloid cell development. Taken together, these results suggest that ethanol has specificity in its effects on differentiation of hematopoietic progenitors.
PMCID: PMC2702472  PMID: 18834972
Rodent; B cells; Monocytes/macrophages; Cell differentiation; Hematopoiesis
4.  CD4+ T Cells Are Required for the Priming of CD8+ T Cells following Infection with Herpes Simplex Virus Type 1▿ † 
Journal of Virology  2009;83(10):5256-5268.
The role of CD4+ helper T cells in modulating the acquired immune response to herpes simplex virus type 1 (HSV-1) remains ill defined; in particular, it is unclear whether CD4+ T cells are needed for the generation of the protective HSV-1-specific CD8+-T-cell response. This study examined the contribution of CD4+ T cells in the generation of the primary CD8+-T-cell responses following acute infection with HSV-1. The results demonstrate that the CD8+-T-cell response generated in the draining lymph nodes of CD4+-T-cell-depleted C57BL/6 mice and B6-MHC-II−/− mice is quantitatively and qualitatively distinct from the CD8+ T cells generated in normal C57BL/6 mice. Phenotypic analyses show that virus-specific CD8+ T cells express comparable levels of the activation marker CD44 in mice lacking CD4+ T cells and normal mice. In contrast, CD8+ T cells generated in the absence of CD4+ T cells express the interleukin 2 receptor α-chain (CD25) at lower levels. Importantly, the CD8+ T cells in the CD4+-T-cell-deficient environment are functionally active with respect to the expression of cytolytic activity in vivo but exhibit a diminished capacity to produce gamma interferon and tumor necrosis factor alpha. Furthermore, the primary expansion of HSV-1-specific CD8+ T cells is diminished in the absence of CD4+-T-cell help. These results suggest that CD4+-T-cell help is essential for the generation of fully functional CD8+ T cells during the primary response to HSV-1 infection.
PMCID: PMC2682109  PMID: 19279095
5.  Dendritic Cells Are Required for Optimal Activation of Natural Killer Functions following Primary Infection with Herpes Simplex Virus Type 1▿  
Journal of Virology  2009;83(7):3175-3186.
Natural killer (NK) cells play an important role in the optimal clearance of herpes simplex virus type 1 (HSV-1) infection in mice. Activated NK cells function via cytokine secretion or direct cytolysis of target cells; dendritic cells (DCs) are thought to make critical contributions in the activation of both of these functions. Yet, the magnitude and physiological relevance of DC-mediated NK cell activation in vivo is not completely understood. To examine the contribution of DC help in regulating NK cell functions after infection with HSV-1, we utilized a transgenic mouse model that allows the transient ablation of DCs. Using this approach, it was found that the gamma interferon (IFN-γ) expression potential of NK cells is quantitatively and qualitatively impaired in the absence of DCs. With regard to priming of NK cytolytic functions, the ablation of DCs did not significantly affect cytotoxic protein expression by NK cells. An in vivo cytolytic assay did, however, reveal impairments in the magnitude of NK cell cytotoxicity. Overall, this study provides direct evidence that functional DCs are required for optimal IFN-γ expression and cytolytic function by NK cells following infection with HSV-1.
PMCID: PMC2655572  PMID: 19144708
6.  In Vivo Ablation of CD11c-Positive Dendritic Cells Increases Susceptibility to Herpes Simplex Virus Type 1 Infection and Diminishes NK and T-Cell Responses 
Journal of Virology  2006;80(8):3985-3993.
The precise role of each of the seven individual CD11c+ dendritic cell subsets (DCs) identified to date in the response to viral infections is not known. DCs serve as critical links between the innate and adaptive immune responses against many pathogens, including herpes simplex virus type 1 (HSV-1). The role of DCs as mediators of resistance to HSV-1 infection was investigated using CD11c-diphtheria toxin (DT) receptor-green fluorescent protein transgenic mice, in which DCs can be transiently depleted in vivo by treatment with low doses of DT. We show that ablation of DCs led to enhanced susceptibility to HSV-1 infection in the highly resistant C57BL/6 mouse strain. Specifically, we showed that the depletion of DCs led to increased viral spread into the nervous system, resulting in an increased rate of morbidity and mortality. Furthermore, we showed that ablation of DCs impaired the optimal activation of NK cells and CD4+ and CD8+ T cells in response to HSV-1. These data demonstrated that DCs were essential not only in the optimal activation of the acquired T-cell response to HSV-1 but also that DCs were crucial for innate resistance to HSV-1 infection.
PMCID: PMC1440460  PMID: 16571815

Results 1-6 (6)