Possible risk mediators in primary dengue virus (DenV) infection that favor secondary DenV infection to life-threatening dengue hemorrhagic fever (DHF) and shock syndrome (DSS) via antibody-dependent enhancement (ADE) have not yet been described. Here, DenV infection enhanced the expression of inflammatory mediators and activation molecules in dendritic cells (DCs) through TLR2/MyD88 pathway. TLR2 appeared to facilitate DenV infection in DCs that were less permissive than macrophages for viral replication.
View Article and Find Full Text PDFJapanese encephalitis (JE) is neuroinflammation characterized by uncontrolled infiltration of peripheral leukocytes into the central nervous system (CNS). We previously demonstrated exacerbation of JE following CD11c dendritic cell (DC) ablation in CD11c-DTR transgenic mice. Moreover, CD11c DC ablation led to abnormal differentiation of CD11bLy-6C monocytes and enhanced permeability of the blood-brain barrier (BBB), resulting in promoting the progression of JE.
View Article and Find Full Text PDFComp Immunol Microbiol Infect Dis
October 2016
Japanese encephalitis (JE), characterized by extensive neuroinflammation following infection with neurotropic JE virus (JEV), is becoming a leading cause of viral encephalitis due to rapid changes in climate and demography. The blood-brain barrier (BBB) plays an important role in restricting neuroinvasion of peripheral leukocytes and virus, thereby regulating the progression of viral encephalitis. In this study, we explored the role of CD11c(hi) dendritic cells (DCs) in regulating BBB integrity and JE progression using a conditional depletion model of CD11c(hi) DCs.
View Article and Find Full Text PDFBackground: CCR5 is a CC chemokine receptor involved in the migration of effector leukocytes including macrophages, NK, and T cells into inflamed tissues. Also, the role of CCR5 in CD4(+)Foxp3(+) regulatory T cell (Treg) homing has recently begun to grab attention. Japanese encephalitis (JE) is defined as severe neuroinflammation of the central nervous system (CNS) following infection with mosquito-borne flavivirus JE virus.
View Article and Find Full Text PDFJapanese encephalitis virus (JEV) is a re-emerging zoonotic flavivirus that poses an increasing threat to global health and welfare due to rapid changes in climate and demography. Although the CCR2-CCL2 axis plays an important role in trafficking CD11b(+) Ly-6C(hi) monocytes to regulate immunopathological diseases, little is known about their role in monocyte trafficking during viral encephalitis caused by JEV infection. Here, we explored the role of CCR2 and its ligand CCL2 in JE caused by JEV infection using CCR2- and CCL2-ablated murine models.
View Article and Find Full Text PDFBackground: Japanese encephalitis (JE), a leading cause of viral encephalitis, is characterized by extensive neuroinflammation following infection with neurotropic JE virus (JEV). Indoleamine 2,3-dioxygenase (IDO) has been identified as an enzyme associated with immunoregulatory function. Although the regulatory role of IDO in viral replication has been postulated, the in vivo role of IDO activity has not been fully addressed in neurotropic virus-caused encephalitis.
View Article and Find Full Text PDFAlthough the roles of dendritic cells (DCs) in adaptive defense have been defined well, the contribution of DCs to T cell-independent innate defense and subsequent neuroimmunopathology in immune-privileged CNS upon infection with neurotropic viruses has not been completely defined. Notably, DC roles in regulating innate CD11b(+)Ly-6C(hi) monocyte functions during neuroinflammation have not yet been addressed. Using selective ablation of CD11c(hi)PDCA-1(int/lo) DCs without alteration in CD11c(int)PDCA-1(hi) plasmacytoid DC number, we found that CD11c(hi) DCs are essential to control neuroinflammation caused by infection with neurotropic Japanese encephalitis virus, through early and increased infiltration of CD11b(+)Ly-6C(hi) monocytes and higher expression of CC chemokines.
View Article and Find Full Text PDFType I interferon (IFN-I)-dependent orchestrated mobilization of innate cells in inflamed tissues is believed to play a critical role in controlling replication and CNS-invasion of herpes simplex virus (HSV). However, the crucial regulators and cell populations that are affected by IFN-I to establish the early environment of innate cells in HSV-infected mucosal tissues are largely unknown. Here, we found that IFN-I signaling promoted the differentiation of CCL2-producing Ly-6Chi monocytes and IFN-γ/granzyme B-producing NK cells, whereas deficiency of IFN-I signaling induced Ly-6Clo monocytes producing CXCL1 and CXCL2.
View Article and Find Full Text PDFBackground: Japanese encephalitis (JE), a neuroinflammation caused by zoonotic JE virus, is the major cause of viral encephalitis worldwide and poses an increasing threat to global health and welfare. To date, however, there has been no report describing the regulation of JE progression using immunomodulatory tools for developing therapeutic strategies. We tested whether blocking the 4-1BB signaling pathway would regulate JE progression using murine JE model.
View Article and Find Full Text PDFT-cell exhaustion has become an important issue in chronic infection because exhausted antigen-specific T cells show impaired abilities to eradicate persistently infected pathogens and produce effector cytokines, such as IFN-γ and TNF-α. Thus, strategies to either restore endogenous exhausted T cell responses or provide functional T cells are needed for therapeutics of chronic infection. Despite promising developments using antibodies and cell immunotherapy, there have been no reported attempts to restore exhausted T cells using treatment with materials derived from natural resources.
View Article and Find Full Text PDFJapanese encephalitis (JE) is major emerging neurologic disease caused by JE virus. To date, the impact of TLR molecules on JE progression has not been addressed. Here, we determined whether each TLR modulates JE, using several TLR-deficient mouse strains (TLR2, TLR3, TLR4, TLR7, TLR9).
View Article and Find Full Text PDFBackground: Control of currently circulating re-assorted low-pathogenicity avian influenza (LPAI) H9N2 is a major concern for both animal and human health. Thus, an improved LPAI H9N2 vaccination strategy is needed to induce complete immunity in chickens against LPAI H9N2 virus strains. Cytokines play a crucial role in mounting both the type and extent of an immune response generated following infection with a pathogen or after vaccination.
View Article and Find Full Text PDFCross-presentation is the pathway by which exogenous antigens are routed for presentation by MHC class I molecules leading to activation of antiviral CD8(+) T-cell responses. However, there is little information describing the modulation of cross-presentation and the impact of pathogen-derived signals associated with Japanese encephalitis virus (JEV), which is one of the most common causes of encephalitis in humans. In this study, we demonstrate that JEV infection could suppress in vivo cross-presentation of soluble and cell-associated antigens, thereby generating weak CD8(+) T-cell responses to exogenous antigens, as evaluated by CFSE dilution of adoptively transferred CD8(+) T cells and in vivo CTL killing activity.
View Article and Find Full Text PDFThe co-administration of two or more cytokines may generate additive or synergistic effects for controlling infectious diseases. However, the practical use of cytokine combinations for the modulation of immune responses against inactivated vaccine has not been demonstrated in livestock yet, primarily due to protein stability, production, and costs associated with mass administration. In light of the current situation, we evaluated the immunomodulatory functions of the combined administration of swine interleukin-18 (swIL-18) and interferon-α (swIFN-α) against an inactivated PrV vaccine using attenuated Salmonella enterica serovar Typhimurium as a cytokine delivery system.
View Article and Find Full Text PDFThe combined use of cytokines has shown synergistic and/or additive effects in controlling several viral infections of livestock animals. However, little is known concerning the practical use of chicken cytokine combinations to control avian diseases. Here, we investigated the antiviral efficacy of oral co-administration of chicken interferon-α (chIFN-α) and chicken interleukin-18 (chIL-18) using attenuated Salmonella enterica serovar Typhimurium in chickens infected with avian influenza virus (AIV) H9N2.
View Article and Find Full Text PDFEnhancing and/or modulating innate and adaptive immunity by cytokines appears to be greatly useful to provide effective protective immunity against infectious diseases. However, an effective delivery system for mass administration in livestock industry is needed because of limitations such as cost, labor, time, and protein stability. Here the immunomodulatory functions of swine interleukine-18 (swIL-18), known as IFN-γ-inducing factor (IGIF), were evaluated in a vaccination model of pseudorabies virus (PrV) using attenuated Salmonella enterica serovar Typhimurium as the oral delivery system.
View Article and Find Full Text PDFVet Microbiol
December 2011
Low pathogenic avian influenza (LPAI) H9N2 has attracted considerable attention due to severe commercial losses in the poultry industry. Furthermore, avian influenza virus (AIV) H9N2-infected chickens can be a reservoir for viral transmission to mammals including pigs and humans, complicating control of viral mutants. Chicken interferon-alpha (chIFN-α) may be useful as an exogenous antiviral agent to control AIV H9N2 infection.
View Article and Find Full Text PDFComp Immunol Microbiol Infect Dis
July 2011
The enhanced effect of cytokine combinations has been assessed empirically, based on their immunobiological mechanisms. However, far less is known of the enhanced protection of practical cytokine combinations against viral infection in the livestock industry, due to cost and production issues associated with mass administration. This study demonstrates the enhanced protection of oral co-administration of swine interferon-α (swIFN-α) and interleukin-18 (swIL-18) against infection with transmissible gastroenteritis virus (TGEV) in piglets using attenuated Salmonella enterica serovar Typhimurium as carrier of cytokine proteins.
View Article and Find Full Text PDFOral administration of attenuated Salmonella vaccine may provide valuable advantages such as low cost, easy preparation, and safety. Attenuated Salmonella vaccines also serve as carriers of foreign antigens and immunomodulatory cytokines. Presently, an attenuated Salmonella enterica serovar Typhimurium strain was used as a carrier for open reading frame 7 (ORF7) protein of porcine reproductive and respiratory syndrome virus (PRRSV), a swine pathogen of significant global economic importance.
View Article and Find Full Text PDFVaccine
July 2010
Enhancing innate and acquired immunity by cytokines such as IFN-alpha appears to be useful as a first line of defense against viral infection. However, the practical use of cytokines in livestock is not evident due to cost and production issues associated with mass administration. In this study, we tested the efficacy of live attenuated Salmonella enterica serovar Typhimurium designed to secrete swine IFN-alpha (swIFN-alpha) protein for preventing the clinical signs caused by infection with transmissible gastroenteritis virus (TGEV), one of the diarrhea-causing viruses in the swine industry.
View Article and Find Full Text PDFCholera toxin, which has been frequently used as mucosal adjuvant, leads to an irreversible activation of adenylyl cyclase, thereby accumulating cAMP in target cells. Here, it was assumed that beta(2)-adrenergic agonist salbutamol may have modulatory functions of immunity induced by DNA vaccine, since beta(2)-adrenergic agonists induce a temporary cAMP accumulation. To test this assumption, the present study evaluated the modulatory functions of salbutamol co-administered with DNA vaccine expressing gB of herpes simplex virus (HSV) via intranasal (i.
View Article and Find Full Text PDFThis study demonstrates a requirement for NF-kappaB activation in cis-diamminedichloroplatinum (cisplatin)-induced apoptosis in human head and neck squamous cell carcinoma (HNSCC) cell lines. This conclusion was supported by the following observations: cisplatin induced IkappaBalpha degradation and NF-kappaB-dependent transcriptional activation prior to cell death; pyrrolidine dithiocarbamate (PDTC), a chemical inhibitor of NF-kappaB activation, prevented apoptosis; lactacystin, an inhibitor of IkappaBalpha degradation, also prevented apoptosis; and finally, the expression of a super-repressor mutant IkappaBalpha blocked apoptosis. The expression of tumor necrosis factor alpha (TNFalpha) was promoted by cisplatin treatment and was suppressed by PDTC treatment.
View Article and Find Full Text PDFCisplatin is a widely used chemotherapeutic agent in head and neck squamous cell carcinoma (HNSCC). Resistance to cisplatin is a common feature of HNSCC. To identify genes that may regulate cisplatin sensitivity, we carried out a cDNA microarray analysis of gene expression in cisplatin-sensitive and cisplatin-resistant HNSCC-derived cell lines.
View Article and Find Full Text PDFIn Korea, mass mortality occurred among cultured shrimp with visible macroscopic white spots in 2000, and we confirmed the presence of white spot syndrome virus (WSSV) in the tissues of moribund shrimp by electron microscopy. In order to identify the characteristics of this Korean isolate of WSSV, we cloned and characterized its genomic DNA coding for VP24, VP26, and VP28. On the nucleotide level, VP24, VP26, and VP28 of the Korean isolate were found to be 100%, 100%, and 99% identical to those of Taiwan, Thailand and Chinese isolates, respectively.
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