[show abstract][hide abstract] ABSTRACT: IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV) causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs) and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg) efficiently induces IL-23 secretion in a mannose receptor (MR)-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg) can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4(+) T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.
[show abstract][hide abstract] ABSTRACT: Background: It is well known that both heat shock protein (HSP) and Toll-like receptor (TLR)3 agonist polyinosinic:polycytidylic acid (poly(I:C)) are capable of promoting the antigen-specific immune responses. In the current study, we assessed whether the anti-tumor effects of the HPV16E7(49-57)-based vaccine can be elevated by combined applications of poly(I:C) and oxygen-regulated protein 150 (ORP150) in a mouse cervical cancer model. Methods: Recombinant mouse ORP150 and HPV E7(49-57) peptide were combined to passively form the ORP150-E7(49-57) complex under heat shock conditions. The effects of ORP150-E7(49-57) complex plus poly(I:C) adjuvant on lymphocyte proliferation and functional cytotoxic T cells were investigated by methyl thiazolyl tetrazolium (MTT), ELISPOT, and non-radioactive cytotoxicity assays. Finally, the complex's therapeutic anti-tumor effects with and without adjuvant therapy were observed in a tumor challenge experiment. Results: This combination vaccine approach significantly enhanced the proliferation of splenocytes and induced strong E7(49-57)-speciﬁc CTL responses. More importantly, the ORP150-E7(49-57) complex plus poly(I:C) vaccine format demonstrated more potent anti-tumor effects than ORP150-E7(49-57) complex alone or E7(49-57) plus poly(I:C) in TC-1 tumor-bearing mice. Conclusion: Both poly(I:C) and ORP150 chaperone can synergistically enhance the anti-tumor effects of the HPV16E7(49-57)-based vaccine in vitro and in vivo. This strategy provides a platform for the design of a tumor therapeutic vaccine capable of inducing an effective anti-tumor immune response.
[show abstract][hide abstract] ABSTRACT: Regulatory T cells (Tregs) are required for proper maintenance of immunological self-tolerance and immune homeostasis. Folate receptor 4 (FR4) is expressed at high levels in transforming growth factor-beta (TGF-β)-induced Tregs and natural Tregs. Moreover, antibody-mediated targeting of FR4 is sufficient to mediate Treg depletion.
In this study, we describe a novel FR4 transcript variant, FR4D3, in which exon 3 is deleted. The mRNA of FR4D3 encodes a FR4 variant truncated by 189 bp. FR4D3 was found to be predominantly expressed in CD4(+)CD25(+) Treg cells. Overexpression of FR4D3 in CD4(+)CD25(+) Treg cells in vitro stimulated proliferation, which may modulate the ability of these cells to bind and incorporate folic acid.
Our results suggested that high levels of FR4D3 may be critical to support the substantial proliferative capacity of Treg cells.
[show abstract][hide abstract] ABSTRACT: Alzheimer's disease (AD) is an age-related, progressive and irreversible neurodegenerative disease that results in the loss of selected neurons throughout the basal forebrain, amygdala, hippocampus, and cortical area as well as progressive deficits of cognition and memory. The subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) is one of the regions where adult neurogenesis occurs in mammals, including humans and non-human primates. The new granule cells, which are the primary excitatory neurons in the DG, contribute to the processes of learning and memory. The changes in neurogenesis observed during the initial stages and progression of AD suggest that the modulation of the new production of neurons at neurogenic sites may exert profound effects on hippocampal function. Bone morphogenetic protein-4 (BMP4) and its antagonist Noggin contribute to the modulation of neurogenesis in the adult hippocampus, thereby affecting hippocampal function. This review focuses on the role of BMP4 and Noggin in the control of the stem and precursor cells in the adult hippocampus during AD and their potential as a possible therapeutic strategy for AD sufferers. It is helpful to extend the understanding of the control of stem cells in the normal and diseased hippocampus.
Ageing research reviews 06/2012; 12(1):157-164. · 5.62 Impact Factor
[show abstract][hide abstract] ABSTRACT: CD4⁺ T cells serve as master regulators of the adaptive immune response to HBV. However, CD4⁺ T-cell subsets are heterogeneous, and it remains unknown how the antiviral agents affect the different CD4⁺ T cell subtypes. To this end, the expressions of signature transcription factors and cytokines of CD4⁺ T-cell subtypes were examined in hepatitis B patients before and after treatment with telbivudine. Results showed that, upon the rapid HBV copy decrease induced by telbivudine treatment, the frequencies and related cytokines of Th17 and Treg cells were dramatically decreased, while those for Th2 cells were dramatically increased. No obvious changes were observed in Th1 cell frequencies; although, IFN-γ expression was upregulated in response to telbivudine treatment, suggesting another cell source of IFN-γ in CHB patients. Statistical analyses indicated that Th17 and Tr1 (a Treg subtype) cells were the most sensitive subpopulations of the peripheral blood CD4⁺ T cells to telbivudine treatment over 52 weeks. Thus, Th17 and Tr1 cells may represent a suitable and effective predictor of responsiveness during telbivudine therapy. These findings not only improve our understanding of hepatitis pathogenesis but also can aid in future development of appropriate therapeutic strategies to control viral hepatitis.
Mediators of Inflammation 01/2012; 2012:789859. · 3.88 Impact Factor
[show abstract][hide abstract] ABSTRACT: Vasoactive intestinal peptide (VIP) is a multifunctional neuropeptide with demonstrated immunosuppressive and neuroprotective activities. It has been shown to inhibit Amyloid beta (Aβ)-induced neurodegeneration by indirectly suppressing the production and release of a variety of inflammatory and neurotoxic factors by activated microglia. We demonstrated that VIP markedly increased microglial phagocytosis of fibrillar Aβ42 and that this enhanced phagocytotic activity depended on activation of the Protein kinase C (PKC) signaling pathway. In addition, VIP suppressed the release of tumor necrosis factor alpha (TNF-α) and nitric oxide (NO) from microglia activated by combined treatment with fibrillar Aβ42 and low dose interferon-γ (IFN-γ). We utilized an adenovirus-mediated gene delivery method to overexpress VIP constitutively in the hippocampus of APPswPS1 transgenic mice. The Aβ load was significantly reduced in the hippocampus of this animal model of Alzheimer's disease, possibly due to the accumulation and activation of cd11b-immunoactive microglial cells. The modulation of microglial activation, phagocytosis, and secretion by VIP is a promising therapeutic option for the treatment of Alzheimer's disease (AD).
PLoS ONE 01/2012; 7(2):e29790. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Peptide-based vaccines derived from the E7 protein of human papillomavirus (HPV) type 16 were developed to induce effective T cell responses against established cervical cancer, but have met with limited clinical success. It is necessary to develop novel peptide-based strategies to substantially improve the immune response against HPV16-related cancer. In this study, we aimed to design a novel peptide-based self-assembled nanoparticle HPV16 vaccine by combining the cell-penetrating peptide HIV-1 Tat(49-57) that was fused with the HPV16 E7(49-57) cytotoxic T lymphocyte (CTL) epitope and the granulocyte-macrophage colony stimulating factor (GM-CSF) gene, and to investigate how it improves the immune response and the therapeutic outcome ex vivo and in vivo. Nanoparticles were prepared and identified by transmission electron microscopy (TEM), gel retardation and DNase I protection assays. This type of vaccine formulation formed the 20-80 nm nanoparticles, and greatly improved epitope-specific immunity both ex vivo and in vivo. Importantly, this vaccine type was associated with decreased tumor growth and enhanced long-term survival in the prophylactic and therapeutic mouse models. The underlying mechanisms were determined to involve priming of enhanced frequency of CD8(+) memory T subtype cells. These results suggest that the nanoparticle Tat-E7/pGM-CSF represents a promising novel approach to enhance the potency of peptide-based cervical cancer vaccines, and this vaccine design strategy may act as a useful reference for research of virus-associated diseases and specific tumor immunotherapies.
[show abstract][hide abstract] ABSTRACT: Regulatory T cells (Treg) contribute to the crucial immunological processes of self-tolerance and immune homeostasis. Genomic mechanisms that regulate cell fate decisions leading to Treg or conventional T cells (Tconv) lineages and those underlying Treg function remain to be fully elucidated, especially at the histone modification level. We generated high-resolution genome-wide distribution maps of monomethylated histone H3 lysine 4 (H3K4me1) and trimethylated H3K4 (H3K4me3) in human CD4(+)CD25(+)FOXP3(+) Tregs and CD4(+)CD25(+)FOXP3(-) activated (a)Tconv cells by DNA sequencing-by-synthesis. 2115 H3K4me3 regions corresponded to proximal promoters; in Tregs, the genes associated with these regions included the master regulator FOXP3 and the chemokine (C-C motif) receptor 7 (CCR7). 41024 Treg-specific H3K4me1 regions were identified. The majority of the H3K4me1 regions differing between Treg and aTconv cells were located at promoter-distal sites, and in vitro reporter gene assays were used to evaluate and identify novel enhancer activity. We provide for the first time a comprehensive genome-wide dataset of lineage-specific H3K4me1 and H3K4me3 patterns in Treg and aTconv cells, which may control cell type-specific gene regulation. This basic principle is likely not restricted to the two closely-related T cell populations, but may apply generally to somatic cell lineages in adult organisms.
PLoS ONE 01/2011; 6(11):e27770. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: MAGE-A antigens belong to cancer/testis (CT) antigens that are expressed in tumors but not in normal tissues except testis and placenta. MAGE-A antigens and their epitope peptides have been used in tumor immunotherapy trials. MAGE-A4 antigen is extensively expressed in various histological types of tumors, so it represents an attractive target for tumor immunotherapy. In this study, we predicted HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) epitopes of MAGE-A4, followed by peptide/HLA-A*0201 affinity and complex stability assays. Of selected four peptides (designated P1, P2, P3, and P4), P1 (MAGE-A4(286-294), KVLEHVVRV) and P3 (MAGE-A4(272-280), FLWGPRALA) could elicit peptide-specific CTLs both in vitro from HLA-A*0201-positive PBMCs and in HLA-A*0201/K(b) transgenic mice. And the induced CTLs could lyse target cells in an HLA-A*0201-restricted fashion, demonstrating that the two peptides are HLA-A*0201-restricted CTL epitopes and could serve as targets for therapeutic antitumoral vaccination.
Clinical and Developmental Immunology 01/2010; 2010:567594. · 3.06 Impact Factor
[show abstract][hide abstract] ABSTRACT: In addition to the subventricular zone, the dentate gyrus of the hippocampus is one of the few brain regions in which neurogenesis continues into adulthood. Perturbation of neurogenesis can alter hippocampal function, and previous studies have shown that neurogenesis is dysregulated in Alzheimer disease (AD) brain. Bone morphogenetic protein-4 (BMP4) and its antagonist Noggin have been shown to play important roles both in embryonic development and in the adult nervous system, and may regulate hippocampal neurogenesis. Previous data indicated that increased expression of BMP4 mRNA within the dentate gyrus might contribute to decreased hippocampal cell proliferation in the APPswe/PS1ΔE9 mouse AD model. However, it is not known whether the BMP antagonist Noggin contributes to the regulation of neurogenesis. We therefore studied the relative expression levels and localization of BMP4 and its antagonist Noggin in the dentate gyrus and whether these correlated with changes in neurogenesis in 6–12 mo old APPswe/PS1ΔE9 transgenic mice. Bromodeoxyuridine (BrdU) was used to label proliferative cells. We report that decreased neurogenesis in the APP/PS1 transgenic mice was accompanied by increased expression of BMP4 and decreased expression of Noggin at both the mRNA and protein levels; statistical analysis showed that the number of proliferative cells at different ages correlated positively with Noggin expression and negatively with BMP4 expression. Intraventricular administration of a chimeric Noggin/Fc protein was used to block the action of endogenous BMP4; this resulted in a significant increase in the number of BrdU-labeled cells in dentate gyrus subgranular zone and hilus in APP/PS1 mice. These results suggest that BMP4 and Noggin co-modulate neurogenesis.
Biochemical and Biophysical Research Communications. 07/2009;
[show abstract][hide abstract] ABSTRACT: The versatility of neural precursor cells (NPCs) derived from mouse embryonic stem cells (ESCs) has recently rekindled interests in cell replacement strategies aimed at neurodegenerative diseases. We observed the survival, migration, differentiation and functional recovery of NPCs transplanted into the hippocampus of aggregated beta-amyloid (Abeta) peptide injured rats. Congo Red plaques, Fluro-jade B positive degenerating neurons and neuronal loss were observed in the Abeta-injured hippocampus of rats, accompanied with significant increases in escape latency and decrease in the ratio of exploratory time in a Morris water maze test. EGFP-expressing mouse ES cells were induced into Nestin-positive NPCs before transplantation into the Abeta-injured hippocampus. A marked decrease in escape latency and exploratory time were observed at least 16 weeks after transplantation compared to Abeta-injured animals without grafts. Grafted EGFP-expressing NPCs spread away from the injection tract and about 12.01+/-0.67% and 9.41+/-0.78% of NPCs differentiated into, respectively, GFAP- and NF200-positive cells 4 W after transplantation. These ratios gradually increased to 40.25+/-0.57% and 19.35+/-0.84% by 16 W. The restoration of hippocampal function by ESCs suggests that cell transplantation may be the effective choice to improve the cognitive function caused by Abeta injured.
Neuroscience Research 10/2008; 62(2):86-96. · 2.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Alterations in hippocampal cell proliferation have been identified in transgenic (tg) mouse models of Alzheimer's disease (AD); however, relatively little is known about the underlying mechanisms. Previously, we have demonstrated that endogenous level of BMP4 in the dentate gyrus (DG) affects hippocampal cell proliferation in a pentylentetrazol kindling-induced epilepsy model. In the present study, we evaluated hippocampal cell proliferation and BMP4 mRNA level in the APPswe/PS1DeltaE9 tg mouse, a well-established mouse model in which coexpression of familial AD-linked APP "Swedish" (APPswe) and PS1DeltaE9 polypeptide variants leads to Abeta deposition throughout the hippocampus and cortex. The number of bromodeoxyuridine (BrdU)-labeled cells in the DG subgranular zone (DG-SGZ) of 9- and 12-month-old APPswe/PS1DeltaE9 tg mice was markedly reduced compared with age-matched nontransgenic littermates, whereas, the BMP4 mRNA level was significantly increased in the tg mice. There was a significant correlation between the increased BMP4 mRNA expression and the decreased number of BrdU labeled cells. After effectively blocking the expression of endogenous BMP4 with antisense oligodeoxynucleotides (ASODN), the decrease in hippocampal cell proliferation in the DG-SGZ and hilus of 9- and 12-month-old tg mice was reversed. These findings suggest that the increased expression of BMP4 mRNA within the DG of the hippocampus may contribute to the decrease in cell proliferation in APPswe/PS1DeltaE9 tg mice.
[show abstract][hide abstract] ABSTRACT: Objective To observe the migration and differentiation of the neural precursor cells (NPCs) that derived from murine embryonic stem
cells (ESCs) when they were transplanted into amyloid β (Aβ)-treated rat hippocampus.
Methods MESPU35, a murine ESC cell line that express the enhanced green fluorescent protein (EGFP), was induced differentiation into
nestin-positive NPCs by modified serum-free methods. The Aβ plaques and the differentiation of the grafted cells were observed
by immunofluorescent staining.
Results Comparing 16 weeks with 4 weeks post-transplantation, the migration distance increased about 5 times; the rate of migratory
NPCs differentiating into glial fibrillary acidic protein (GFAP)-positive cells kept rising from (30.41±1.45)% to (49.25±1.23)%,
and the rate of NPCs differentiating into neurofilament 200 (NF200) positive cells increased from (16.68±0.95)% to (27.94±1.21)%.
Meanwhile, the GFAP-positive cells targeting to the ipsilateral side of Aβ plaques increased from 60.2% to 81.3%, while the
NF200-positive cells increased from 61.3% to 84.1%. The migration distance had significant positive linear correlations to
the neuronal differentiation rate (r = 0.991) and to the astrocytic differentiation rate (r = 0.953).
Conclusion Engrafted NPCs migrate targetedly to the Aβ injection site and differentiate into neurons and astrocytes.
[show abstract][hide abstract] ABSTRACT: The pluripotency and high proliferative capacity of embryonic stem (ES) cells make them an attractive source of different cell types for biomedical research and cell replacement therapies. It has been demonstrated that ES cells can be induced into neural precursor cells (NPCs) under conditions. NPCs can be expanded in large numbers for significant periods of time to provide a reliable source of cells for transplantation in neurodegenerative disorders and injury of the central nervous system. This study describes a modified method for generation of NPCs from cultured mouse ES cells.
Brain Research Protocols 06/2005; 15(1):52-8. · 1.82 Impact Factor
[show abstract][hide abstract] ABSTRACT: Pluripotent embryonic stem (ES) cells are the most versatile cells, with the potential to differentiate into all types of cell lineages including neural precursor cells (NPCs), which can be expanded in large numbers for significant periods of time to provide a reliable cell source for transplantation in neurodegenerative disorders such as Parkinson's disease (PD). In the present study, we used the MESPU35 mouse ES cell line, which expresses enhanced green fluorescent protein that enables one to distinguish between transplanted cells and cells of host origin. Embryoid bodies (EBs) were formed and were induced to NPCs in N2 selection medium plus fibronectin. Praxiology and immunohistochemistry methods were used to observe the survival, differentiation, and therapeutic effect of NPCs after grafted into the striatum of PD rats. We found that mouse ESc were differentiated into nestin-positive NPCs 6 days after the EBs formed and cultured in the N2 selection medium. The number of survival NPCs was increased significantly by fibronectin. About 23.76+/-2.29% of remaining cells were tyrosine hydroxylase (TH)-positive 12 days after NPCs were cultured in N2 selective medium. The survival rates of NPCs were 2.10+/-0.41% and about 90.90+/-3.00% of the engrafted NPCs were TH-positive 6 weeks after transplantation into the striatum of PD rats. The rotation of PD rats was relieved 3 weeks after the NPCs transplantation and this effect was kept for at least 6 weeks. It suggests that most of the survival NPCs derived from ES cells differentiated into TH-positive neurons after grafted into the striatum of PD rats, which produces therapeutic effect on PD.
Biochemical and Biophysical Research Communications 02/2005; 326(1):115-22. · 2.41 Impact Factor