Publications by authors named "Ramesh C Halder"

Article Synopsis
  • The study found that normal mice have αβ T cells that specifically recognize self-glycerophospholipids, like phosphatidic acid (PA), in a way that is restricted by CD1d without cross-reacting with iNKT-cell ligands.
  • Glycerophospholipids, such as PA, can effectively compete for binding to CD1d, potentially influencing immune balance between lipid-reactive T cell subsets, which has significant health implications.
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We have investigated transcriptional and epigenetic differences in peripheral blood mononuclear cells (PBMCs) of monozygotic female twins discordant in the diagnosis of amyotrophic lateral sclerosis (ALS). Exploring DNA methylation differences by reduced representation bisulfite sequencing (RRBS), we determined that, over time, the ALS twin developed higher abundances of the CD14 macrophages and lower abundances of T cells compared to the non-ALS twin. Higher macrophage signature in the ALS twin was also shown by RNA sequencing (RNA-seq).

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Sporadic ALS patients display heterogeneous immune pathways in peripheral blood mononuclear cells (PBMCs). We tested nine sALS patients and one unaffected identical twin of an index case by RNA-Seq of PBMCs. The inflammatory patients (n = 3) clustered into a subset with an inflammatory Th1/Th17 signature and the non-inflammatory patients (n = 7) into another subset with a B cell signature.

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Systemic autoimmune diseases such as lupus affect multiple organs, usually in a diverse fashion where only certain organs are affected in individual patients. It is unclear whether the "local" immune cells play a role in regulating tissue specificity in relation to disease heterogeneity in systemic autoimmune diseases. In this study, we used skin as a model to determine the role of tissue-resident dendritic cells (DCs) in local and systemic involvement within a systemic lupus disease model.

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Pancreatic cancer has a poor prognosis attributed in part to immune suppression and deactivation of natural killer (NK) cells. Curcuminoids have a potential for improving the therapy of pancreatic cancer given promising results in cancer models and a clinical trial, but their oral absorption is limited. Our objective in this study is to show curcuminoid anti-oncogenic effects alone and together with human NK cells.

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We investigated the effects of 4-17 month supplementation with ω-3 fatty acids and antioxidants (Smartfish drink; Smartfish AS, Oslo, Norway) in 12 patients with minor cognitive impairment (MCI) [minimental state examination (MMSE) ≥19], 2 patients with pre-MCI (normal MMSE), and 7 patients with Alzheimer disease (AD) (MMSE <19). We measured the phagocytosis of amyloid-β 1-42 (Aβ) by flow cytometry and microscopy, the transcription of inflammatory genes by RT-PCR, the production of resolvin D1 (RvD1) by enzyme immunoassay, and the cognitive status by MMSE. In patients with MCI and pre-MCI, phagocytosis of Aβ by monocytes increased from 530 to 1306 mean fluorescence intensity units (P = 0.

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Introduction: β2-microglobulin (β2m) is required for the surface expression of MHC class I and class I-like proteins such as CD1d, Qa1 and neonatal Fc receptor (FcRn), all of which may impact the development of autoimmunity. Since CD1d is known to bind and present phospholipid antigens to T cells, we asked if the deficiency of β2m or CD1d will impact the development of anti-phospholipid antibodies as compared to other aspects of lupus autoimmunity.

Methods: We introgressed the β2m-null genotype onto the NZB and NZW backgrounds for 12 to 14 generations to generate genetically lupus-susceptible (NZB/NZW)F1 (BWF1) mice that are β2m-deficient (β2m°).

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Natural Killer T (NKT) cells recognize both self and foreign lipid Ags presented by CD1 molecules. Although presentation of the marine sponge-derived lipid alphaGalCer to type I NKT cells has been well studied, little is known about self-glycolipid presentation to either type I or type II NKT cells. Here we have investigated presentation of the self-glycolipid sulfatide to a type II NKT cell that specifically recognizes a single species of sulfatide, namely lyso-sulfatide but not other sulfatides containing additional acyl chains.

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Negative immunoregulation is a major barrier to successful cancer immunotherapy. The NKT cell is known to be one such regulator. In this study we explored the roles of and interaction between the classical type I NKT cell and the poorly understood type II NKT cell in the regulation of tumor immunity.

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Because of the paucity of known self lipid-reactive ligands for NKT cells, interactions among distinct NKT cell subsets as well as immune consequences following recognition of self glycolipids have not previously been investigated. Here we examined cellular interactions and subsequent immune regulatory mechanism following recognition of sulfatide, a self-glycolipid ligand for a subset of CD1d-restricted type II NKT cells. Using glycolipid/CD1d tetramers and cytokine responses, we showed that activation of sulfatide-reactive type II NKT cells and plasmacytoid DCs caused IL-12- and MIP-2-dependent recruitment of type I, or invariant, NKT (iNKT) cells into mouse livers.

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Here we briefly review our understanding of the immune response to myelin-derived glycolipids during an inflammatory autoimmune response in the central nervous system (CNS). We focus primarily on the recognition of the self-glycolipid sulfatide by a distinct population of non-invariant NK T cells. The results of studies we have obtained so far in investigating the presentation of sulfatide by CNS-resident cells including microglia and their interactions with T cells indicate that this pathway might be successfully targeted for the treatment of autoimmune demyelination in multiple sclerosis.

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Class I and class II MHC-restricted T cells specific for proteins present in myelin have been shown to be involved in autoimmunity in the central nervous system (CNS). It is not yet known whether CD1d-restricted T cells reactive to myelin-derived lipids are present in the CNS and might be targeted to influence the course of autoimmune demyelination. Using specific glycolipid-CD1d tetramers and cloned T cells we have characterized a T cell population reactive to a myelin-derived glycolipid, sulfatide, presented by CD1d.

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Plasmodium yoelii-infected erythrocytes were injected into mice with or without 6.5 Gy irradiation. This irradiation suppressed erythropoiesis and induced severe immunosuppression.

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Immunological states during human malarial infection were examined. In parallel with parasitemia and anemia, granulocytosis was induced in the blood of patients, especially those infected with Plasmodium (P.) falciparum.

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Natural killer T (NKT) cells and CD5(+)B cells were searched for in various immune organs of autoimmune prone (NZBxNZW)F(1) (NZB/W F(1)) mice. The number of lymphocytes increased in the liver, spleen, and peritoneal cavity after the onset of disease (at the age of 30 weeks) while the number of thymocytes decreased at that time. Prominent changes of lymphocyte subsets were seen in the liver and peritoneal cavity, namely, expansion of IL-2Rbeta(+)TCRalpha beta(int) cells in the liver and of CD5(+)B220(+) cells in the peritoneal cavity.

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Athymic nude mice carry neither conventional T cells nor NKT cells of thymic origin. However, NK1.1(-)TCR(int) cells are present in the liver and other immune organs of athymic mice, because these lymphocyte subsets are truly of extrathymic origin.

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