Browsing by Author "Sathit Pichyangkul"

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    Antiviral immune responses in H5N1-infected human lung tissue and possible mechanisms underlying the hyperproduction of interferon-inducible protein IP-10
    (2010-08-01) Arunee Thitithanyanont; Anneke Engering; Monkol Uiprasertkul; Peeraya Ekchariyawat; Suwimon Wiboon-ut; Romchat Kraivong; Amporn Limsalakpetch; Utaiwan Kum-Arb; Kosol Yongvanitchit; Noppadol Sa-Ard-Iam; Pimprapa Rukyen; Rangsini Mahanonda; Kamon Kawkitinarong; Prasert Auewarakul; Pongsak Utaisincharoen; Stitaya Sirisinha; Carl J. Mason; Mark M. Fukuda; Sathit Pichyangkul; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand; Chulalongkorn University; Chulalongkorn Business School
    Information on the immune response against H5N1 within the lung is lacking. Here we describe the sustained antiviral immune responses, as indicated by the expression of MxA protein and IFN-α mRNA, in autopsy lung tissue from an H5N1-infected patient. H5N1 infection of primary bronchial/tracheal epithelial cells and lung microvascular endothelial cells induced IP-10, and also up-regulated the retinoic acid-inducible gene-I (RIG-I). Down-regulation of RIG-I gene expression decreased IP-10 response. Co-culturing of H5N1-infected pulmonary cells with TNF-α led to synergistically enhanced production of IP-10. In the absence of viral infection, TNF-α and IFN-α also synergistically enhanced IP-10 response. Methylprednisolone showed only a partial inhibitory effect on this chemokine response. Our findings strongly suggest that both the H5N1 virus and the locally produced antiviral cytokines; IFN-α and TNF-α may have an important role in inducing IP-10 hyperresponse, leading to inflammatory damage in infected lung. © 2010.
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    CpG DNA, liposome and refined antigen oral cholera vaccine
    (2003-12-01) Ratree Leelawongtawon; Srinuan Somroop; Urai Chaisri; Pongsri Tongtawe; Manas Chongsa-nguan; Thareerat Kalambaheti; Pramuan Tapchaisri; Sathit Pichyangkul; Yuwaporn Sakolvaree; Hisao Kurazono; Hideo Hayashi; Wanpen Chaicumpa; Mahidol University; Thammasat University; Armed Forces Research Institute of Medical Sciences, Thailand; Okayama University; University of Tsukuba
    An oral cholera vaccine made up of three Vibrio cholerae antigens, i.e. lipopolysaccharide (LPS), recombinant toxin co-regulated pili (rTcpA) and heat-treated cholera toxin (H-CT) has been developed in six different formulations. Eight-week-old Wistar rats were divided into nine groups and immunized as follows: the first group received the oral vaccine 1 consisting of the three antigens (LPS, rTcpA and H-CT) associated with a liposome (L) and bacterial CpG-DNA (ODN#1826). The rats of groups 2 and 3 received oral vaccines 2 and 3 consisting of the liposome-associated three antigens with and without non-bacterial CpG-DNA (ODN#1982), respectively. Rats of groups 4 received oral vaccine 4 consisting of the three antigens mixed with the ODN#1826, similar to vaccine 1, but without liposome. Rats of groups 5 and 6 received oral vaccines 5 and 6 consisting of the three antigens with and without ODN#1982, respectively, similar to vaccines 2 and 3, but without liposome. Rats of groups 7, 8 and 9 received oral placebos, namely liposomes (L), ODN#1826 (CpG), and vaccine diluent, i.e. 5% NaHCO3solution, respectively. All vaccines were given in three doses at 14-day intervals. It was found that the combination of liposome and ODN#1826 in vaccine 1 evoked the highest immune response to V. cholerae antigen compared to other vaccine formulations and placebos, as measured by the appearance of antigen-specific antibody-producing cells in the intestinal lamina propria. The immunogenicity according to the magnitude of the immune response was: V1>V2=V3>V4>V5=V6>V7=V8=V9. The results of this study indicate that CpG-DNA and liposome are effective mucosal adjuvants for an oral cholera vaccine prepared from refined V. cholerae antigens and their combination seems to be synergistic. The potential role of liposome as a vaccine delivery vehicle has been confirmed.
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    Cross-reactive antibodies against avian influenza virus A (H5N1)
    (2009-09-01) Sathit Pichyangkul; Anan Jongkaewwattana; Arunee Thitithanyanont; Peeraya Ekchariyawat; Suwimon Wiboon-ut; Amporn Limsalakpetch; Kosol Yongvanitchit; Utaiwan Kum-Arb; Rangsini Mahanonda; Pongsak Utaisincharoen; Stitaya Sirisinha; Carl J. Mason; Mark M. Fukuda; Armed Forces Research Institute of Medical Sciences, Thailand; National Center for Genetics Engineering and Biotechnology; Mahidol University; Chulalongkorn University
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    The effects of Porphyromonas gingivalis LPS and Actinobacillus actinomycetemcomitans LPS on human dendritic cells in vitro, and in a mouse model in vivo
    (2006-12-01) Rangsini Mahanonda; Piyawadee Pothiraksanon; Noppadol Sa-Ard-Iam; Kazuhisa Yamazaki; Robert E. Schifferle; Chakrit Hirunpetcharat; Kosol Yongvanichit; Sathit Pichyangkul; Chulalongkorn University; Niigata University School of Medicine; University at Buffalo, State University of New York; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand
    Interaction between different bacterial plaque pathogens and dendritic cells may induce different types of T helper (Th) cell response, which is critical in the pathogenesis of periodontitis. In this study we investigated the effects of lipopolysaccharide (LPS) from Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans on human monocyte-derived dendritic cells (Mo-DCs) with respect to co-stimulatory molecule expression, cytokine production and Th cell differentiation. Unlike Escherichia coli and A. actinomycetemcomitans LPS, P. gingivalis LPS induced only low levels of CD40, CD80, HLA-DR and CD83 expression on Mo-DCs. LPS from both bacteria induced considerably lower TNF-α and IL-10 than did E. coli LPS. LPS from all three bacteria induced only negligible IL-12 production. In a human mixed-leukocyte reaction, and in an ovalbumin-specific T cell response assay in mice, both types of LPS suppressed IFN-γ production. In conclusion, stimulation by P. gingivalis LPS and A. actinomycetemcomitans LPS appears to bias Mo-DCs towards Th2 production.
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    Evaluation of In Vitro Cross-Reactivity to Avian H5N1 and Pandemic H1N1 2009 Influenza Following Prime Boost Regimens of Seasonal Influenza Vaccination in Healthy Human Subjects: A Randomised Trial
    (2013-03-26) Delia Bethell; David Saunders; Anan Jongkaewwattana; Jarin Kramyu; Arunee Thitithayanont; Suwimon Wiboon-ut; Kosol Yongvanitchit; Amporn Limsalakpetch; Utaiwan Kum-Arb; Nichapat Uthaimongkol; Jean Michel Garcia; Ans E. Timmermans; Malik Peiris; Stephen Thomas; Anneke Engering; Richard G. Jarman; Duangrat Mongkolsirichaikul; Carl Mason; Nuanpan Khemnu; Stuart D. Tyner; Mark M. Fukuda; Douglas S. Walsh; Sathit Pichyangkul; Armed Forces Research Institute of Medical Sciences, Thailand; Thailand National Center for Genetic Engineering and Biotechnology; Mahidol University; The University of Hong Kong
    Introduction: Recent studies have demonstrated that inactivated seasonal influenza vaccines (IIV) may elicit production of heterosubtypic antibodies, which can neutralize avian H5N1 virus in a small proportion of subjects. We hypothesized that prime boost regimens of live and inactivated trivalent seasonal influenza vaccines (LAIV and IIV) would enhance production of heterosubtypic immunity and provide evidence of cross-protection against other influenza viruses. Methods: In an open-label study, 26 adult volunteers were randomized to receive one of four vaccine regimens containing two doses of 2009-10 seasonal influenza vaccines administered 8 (±1) weeks apart: 2 doses of LAIV; 2 doses of IIV; LAIV then IIV; IIV then LAIV. Humoral immunity assays for avian H5N1, 2009 pandemic H1N1 (pH1N1), and seasonal vaccine strains were performed on blood collected pre-vaccine and 2 and 4 weeks later. The percentage of cytokine-producing T-cells was compared with baseline 14 days after each dose. Results: Subjects receiving IIV had prompt serological responses to vaccine strains. Two subjects receiving heterologous prime boost regimens had enhanced haemagglutination inhibition (HI) and neutralization (NT) titres against pH1N1, and one subject against avian H5N1; all three had pre-existing cross-reactive antibodies detected at baseline. Significantly elevated titres to H5N1 and pH1N1 by neuraminidase inhibition (NI) assay were observed following LAIV-IIV administration. Both vaccines elicited cross-reactive CD4+ T-cell responses to nucleoprotein of avian H5N1 and pH1N1. All regimens were safe and well tolerated. Conclusion: Neither homologous nor heterologous prime boost immunization enhanced serum HI and NT titres to 2009 pH1N1 or avian H5N1 compared to single dose vaccine. However heterologous prime-boost vaccination did lead to in vitro evidence of cross-reactivity by NI; the significance of this finding is unclear. These data support the strategy of administering single dose trivalent seasonal influenza vaccine at the outset of an influenza pandemic while a specific vaccine is being developed. Trial Registration: ClinicalTrials.gov NCT01044095. © 2013 Bethell, et al.
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    Expression of Toll-like receptors on antigen-presenting cells in patients with falciparum malaria
    (2008-01-01) Somying Loharungsikul; Marita Troye-Blomberg; Petra Amoudruz; Sathit Pichyangkul; Kosol Yongvanitchit; Sornchai Looareesuwan; Yuvadee Mahakunkijcharoen; Suphannee Sarntivijai; Srisin Khusmith; Mahidol University; Stockholms universitet; Armed Forces Research Institute of Medical Sciences, Thailand; The Hospital for Tropical Diseases, Bangkok
    The continuous release of blood-stage malaria parasites and their products can activate components of the innate immune system and induce the production of proinflammatory cytokines. Toll-like receptors (TLRs) have emerged as pattern-recognition receptors, residing on/in innate immune cells whose function is recognizing specific conserved components on different microbes. The aim of this study was to determine the expression of TLR2, TLR4 and TLR9 on antigen-presenting cells (APCs) in patients with mild and severe forms of falciparum malaria. Healthy individuals were used as controls. Peripheral blood mononuclear cells (PBMCs) were stained with specific monoclonal antibodies (mAbs) to investigate the percentage and the level of TLR expression by flow cytometry. Patients with severe and mild malaria showed increased surface expression of TLR2 and TLR4 on CD14+monocytes and myeloid dendritic cells (MDCs) and decreased intracellular expression of TLR9 on plasmacytoid dendritic cells (PDCs), compared to those of healthy controls. A significant decrease in the percentage of circulating CD14+monocytes and MDCs expressing TLR2 was found in both severe and mild malaria patients. These findings suggested that TLRs might play role in innate immune recognition in which the differential expression of TLRs on APCs could be regulated by the P. falciparum parasite. © 2007 Elsevier B.V. All rights reserved.
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    Generation and preclinical evaluation of a DENV-1/2 prM+E chimeric live attenuated vaccine candidate with enhanced prM cleavage
    (2013-10-17) Poonsook Keelapang; Narong Nitatpattana; Amporn Suphatrakul; Surat Punyahathaikul; Rungtawan Sriburi; Rojjanaporn Pulmanausahakul; Sathit Pichyangkul; Prida Malasit; Sutee Yoksan; Nopporn Sittisombut; Chiang Mai University; Mahidol University; Thailand National Center for Genetic Engineering and Biotechnology; Armed Forces Research Institute of Medical Sciences, Thailand
    In the absence of a vaccine or sustainable vector control measures, illnesses caused by dengue virus infection remain an important public health problem in many tropical countries. During the export of dengue virus particles, furin-mediated cleavage of the prM envelope protein is usually incomplete, thus generating a mixture of immature, partially mature and mature extracellular particles. Variations in the arrangement and conformation of the envelope proteins among these particles may be associated with their different roles in shaping the antibody response. In an attempt to improve upon live, attenuated dengue vaccine approaches, a mutant chimeric virus, with enhanced prM cleavage, was generated by introducing a cleavage-enhancing substitution into a chimeric DENV-1/2 virus genome, encoding the prM. +. E sequence of a recent DENV-1 isolate under an attenuated DENV-2 genetic background. A modest increase in virus specific infectivity observed in the mutant chimeric virus affected neither the attenuation phenotype, when assessed in the suckling mouse neurovirulence model, nor multiplication in mosquitoes. The two chimeric viruses induced similar levels of anti-DENV-1 neutralizing antibody response in mice and rhesus macaques, but more efficient control of viremia during viral challenge was observed in macaques immunized with the mutant chimeric virus. These results indicate that the DENV-1/2 chimeric virus, with enhanced prM cleavage, could be useful as an alternative live, attenuated vaccine candidate for further tests in humans. © 2013 Elsevier Ltd.
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    Generation of gingival T cell lines/clones specific with Porphyromonas gingivalis pulsed dendritic cells from periodontitis patients
    (2003-01-01) Nuntana Aroonrerk; Sathit Pichyangkul; Kosol Yongvanitchit; Mahisorn Wisetchang; Noppadol Sa-Ard-lam; Stitaya Sirisinha; Rangsini Mahanonda; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand; Faculty of Medicine, Siriraj Hospital, Mahidol University; Chulalongkorn University
    Objectives and background: It is well documented that in periodontitis lesions, most infiltrated gingival T cells are antigen-specific memory T cells. These cells play an important role as regulators and effector cells in the pathogenesis of periodontitis. In this study, we used dendritic cells (DCs) as antigen-presenting cells to generate human gingival T cell lines and clones specific for Porphyromonas gingivalis from periodontitis patients. Methods: Autologous DCs were derived from the patients' adherent monocytes using granulocyte-macrophage colony-stimulating factor and interleukin (IL)-4. Lymphocytes were isolated from gingival biopsies using collagenase enzyme digestion and the number was increased by subsequent culturing in IL-2-containing medium. T cells were then negatively sorted using flow cytometry, cocultured with P. gingivalis-pulsed DCs and subsequently expanded in the culture medium containing IL-2. T cells were kept viable and active by periodic exposure to antigen-pulsed DCs. The specificity of the T cell lines was tested against four plaque bacteria: P. gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia and Actinomyces viscosus. The established T cell lines were then cloned. Three P. gingivalis-specific T cell lines and 12 gingival T cell clones were generated. They all showed good specificity against P. gingivalis but not to other plaque bacteria. Results: All T cell clones were positive for CD4 and the majority of them produced interferon gamma, but a minimal or negligible amount of IL-5. Conclusions: The data obtained clearly showed that monocyte-derived DCs could be used as powerful antigen-presenting cells to generate antigen-specific T cells from periodontitis tissues.
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    Generation of Porphyromonas gingivalis-specific t cells by dendritic cells from periodontitis patients
    (Mahidol University. Mahidol University Library and Knowledge Center, 2023) Nuntana Aroonrerk; Stitaya Sirisinha; Sathit Pichyangkul; Rangsini Mahanonda
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    High susceptibility of human dendritic cells to avian influenza H5N1 virus infection and protection by IFN-α and TLR ligands
    (2007-10-15) Arunee Thitithanyanont; Anneke Engering; Peeraya Ekchariyawat; Suwimon Wiboon-ut; Amporn Limsalakpetch; Kosol Yongvanitchit; Utaiwan Kum-Arb; Watcharoot Kanchongkittiphon; Pongsak Utaisincharoen; Stitaya Sirisinha; Pilaipan Puthavathana; Mark M. Fukuda; Sathit Pichyangkul; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand
    There is worldwide concern that the avian influenza H5N1 virus, with a mortality rate of >50%, might cause the next influenza pandemic. Unlike most other influenza infections, H5N1 infection causes a systemic disease. The underlying mechanisms for this effect are still unclear. In this study, we investigate the interplay between avian influenza H5N1 and human dendritic cells (DC). We showed that H5N1 virus can infect and replicate in monocyte-derived and blood myeloid DC, leading to cell death. These results suggest that H5N1 escapes viral-specific immunity, and could disseminate via DC. In contrast, blood pDC were resistant to infection and produced high amounts of IFN-α. Addition of this cytokine to monocyte-derived DC or pretreatment with TLR ligands protected against infection and the cytopathic effects of H5N1 virus.
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    Immunostimulatory CpG oligodeoxynucleotide confers protection in a murine model of infection with Burkholderia pseudomallei
    (2004-08-01) Surasakdi Wongratanacheewin; Wannapa Kespichayawattana; Pakamas Intachote; Sathit Pichyangkul; Rasana W. Sermswan; Arthur M. Krieg; Stitaya Sirisinha; Khon Kaen University; Chulabhorn Research Institute; Armed Forces Research Institute of Medical Sciences, Thailand; Mahidol University; Pfizer Inc.
    Although CpG oligodeoxynucleotides (CpG ODNs) are known to enhance resistance against infection in a number of animal models, little is known about the CpG-induced protection against acute fatal sepsis such as that associated with the highly virulent bacterium Burkholderia pseudomallei. We previously demonstrated in an in vitro study that immunostimulatory CpG ODN 1826 enhances phagocytosis of B. pseudomallei and induces nitric oxide synthase and nitric oxide production by mouse macrophages. In the present study, CpG ODN 1826 given intramuscularly to BALB/c mice 2 to 10 days prior to B. pseudomallei challenge conferred better than 90% protection. CpG ODN 1826 given 2 days before the bacterial challenge rapidly enhanced the innate immunity of these animals, judging from the elevated serum levels of interleukin-12 (IL-12)p70 and gamma interferon (IFN-γ) over the baseline values. No bacteremia was detected on day 2 in 85 to 90% of the CpG-treated animals, whereas more than 80% of the untreated animals exhibited heavy bacterial loads. Although marked elevation of IFN-γ was found consistently in the infected animals 2 days after the bacterial challenge, it was ameliorated by the CpG ODN 1826 pretreatment (P = 0.0002). Taken together, the kinetics of bacteremia and cytokine profiles presented are compatible with the possibility that protection by CpG ODN 1826 against acute fatal septicemic melioidosis in this animal model is associated with a reduction of bacterial load and interference with the potential detrimental effect of the robust production of proinflammatory cytokines associated with B. pseudomallei multiplication.
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    Induction of immunity to plasmodium yoelii MSP1 19 by intranasal immunization using different mucosal adjuvants
    (Mahidol University. Mahidol University Library and Knowledge Center, 2007) Warunee Chaigamphang; Chakrit Hirunpetcharat; Fuangfa Utrarachkij; Sathit Pichyangkul
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    Interplay between B cells and highly pathogenic avian influenza H5N1 Virus (HPAI H5N1)
    (Mahidol University. Mahidol University Library and Knowledge Center, 2023) Prasit Na-Ek; Arunee Thitithanyanont; Prasert Auewarakul; Sathit Pichyangkul; Pongsak Utaisincharoen
    Major complications of avian influenza A H5N1 virus (HPAI H5N1) infection are with the systemic organs spreading. Mostly the severe cases have hematopoietic abnormality and viremia. Many types of immune cells have been reported to be targets of this virus. However, there is limited information available about B cells susceptibility. Our preliminary results demonstrated that HPAI H5N1 could infect B cells in PBMCs with much higher degree as compared with purified B cells. The data also supported that B cells must interact with monocytes in PBMCs to increase the susceptibility to HPAI H5N1. In this study we explored the interaction of B cells and monocytes and their roles for enhancing susceptibility of B cells to this virus. After 12 hours post infection (hpi), we demonstrated that B-cells in B cells and monocytes (B/M) co-cultures and B cells in PBMCs had 36.73±29.03% and 68.87±17.44% of infected cells, which was significantly higher than purified B cells alone, 4.59±2.55%. We studied further on the presence of a sialic acid receptor on the HPAI H5N1 infected B cells, and found that the number of α(2,3)SA receptor positive on B cells were significantly increased from 0.72±0.08% in B cells alone to 53.87±13.20% in B cells in B/M co-cultures. We also demonstrated a positive correlation between numbers of cells with α(2,3)SA receptor and numbers of B cells with HPAI H5N1 infection in B/M co-culture, with the correlation equal to R2=0.98. Moreover, we observed that the enhancement of HPAI H5N1 infection and the increasing of α(2,3)SA receptor on B cells in B/M co-culture required direct cell contact between monocytes and B cells. We examined that total B cells, memory B cells, and naïve B cells were susceptible to HPAI H5N1 with 33.8±2.96%, 29.29±2.10%, and 40.42±3.42 %, respectively. The percentages of infected naïve B cells and the number of α(2,3) SA positive cells in naïve B cells were significantly higher than memory B cells at 48.74±14.17%, and 37.07±6.54%, respectively. These findings provide a better understanding of tropism of HPAI H5N1 to B cells and the interplay of monocytes and B cells in the viral pathogenesis.
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    Long-lasting protective immune response to the 19-kilodalton carboxy-terminal fragment of Plasmodium yoelii merozoite surface protein 1 in mice
    (2007-04-01) Pimmada Jeamwattanalert; Yuvadee Mahakunkijcharoen; Leera Kittigul; Pakpimol Mahannop; Sathit Pichyangkul; Chakrit Hirunpetcharat; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand
    Merozoite surface protein 1 (MSP1) is the major protein on the surface of the plasmodial merozoite, and its carboxy terminus, the 19-kDa fragment (MSP119), is highly conserved and effective in induction of a protective immune response against malaria parasite infection in mice and monkeys. However, the duration of the immune response has not been elucidated. As such, we immunized BALB/c mice with a standard four-dose injection of recombinant Plasmodium yoelii MSP119 formulated with Montanide ISA51 and CpG oligodeoxynucleotide (ODN) and monitored the MSP119-specific antibody levels for up to 12 months. The antibody titers persisted constantly over the period of time without significant waning, in contrast to the antibody levels induced by immunization with Freund's adjuvant, where the antibody levels gradually declined to significantly lower levels 12 months after immunization. Investigation of immunoglobulin G (IgG) subclass longevity revealed that only the IgG1 antibody level (Th2 type-driven response) decreased significantly by 6 months, while the IgG2a antibody level (Th1 type-driven response) did not change over the 12 months after immunization, but the boosting effect was seen in the IgG1 antibody responses but not in the IgG2a antibody responses. After challenge infection, all immunized mice survived with negligibly patent parasitemia. These findings suggest that protective immune responses to MSP119 following immunization using oil-based Montanide ISA51 and CpG ODN as an adjuvant are very long-lasting and encourage clinical trials for malaria vaccine development. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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    Malaria Blood Stage Parasites Activate Human Plasmacytoid Dendritic Cells and Murine Dendritic Cells through a Toll-Like Receptor 9-Dependent Pathway
    (2004-04-15) Sathit Pichyangkul; Kosol Yongvanitchit; Utaiwan Kum-Arb; Hiroaki Hemmi; Shizuo Akira; Arthur M. Krieg; D. Gray Heppner; V. Ann Stewart; Hitoshi Hasegawa; Sornchai Looareesuwan; G. Dennis Shanks; R. Scott Miller; Armed Forces Research Institute of Medical Sciences, Thailand; Osaka University; Pfizer Inc.; Walter Reed Army Institute of Research; Ehime University, School of Medicine; Mahidol University
    A common feature of severe Plasmodium falciparum infection is the increased systemic release of proinflammatory cytokines that contributes to the pathogenesis of malaria. Using human blood, we found that blood stage schizonts or soluble schizont extracts activated plasmacytoid dendritic cells (PDCs) to up-regulate CD86 expression and produce IFN-α. IFN-α production was also detected in malaria-infected patients, but the levels of circulating PDCs were markedly reduced, possibly because of schizont-stimulated up-regulation of CCR7, which is critical for PDC migration. The schizont-stimulated PDCs elicited a poor T cell response, but promoted γδ T cell proliferation and IFN-γ production. The schizont immune stimulatory effects could be reproduced using murine DCs and required the Toll-like receptor 9 (TLR9)-MyD88 signaling pathway. Although the only known TLR9 ligand is CpG motifs in pathogen DNA, the activity of the soluble schizont extract was far greater than that of schizont DNA, and it was heat labile and precipitable with ammonium sulfate, unlike the activity of bacterial DNA. These results demonstrate that schizont extracts contain a novel and previously unknown ligand for TLR9 and suggest that the stimulatory effects of this ligand on PDCs may play a key role in immunoregulation and immunopathogenesis of human falciparum malaria.
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    MxA expression induced by α-defensin in healthy human periodontal tissue
    (2012-04-01) Rangsini Mahanonda; Noppadol Sa-Ard-Iam; Pimprapa Rerkyen; Arunee Thitithanyanont; Keskanya Subbalekha; Sathit Pichyangkul; Chulalongkorn University; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand
    Although periodontal tissue is continually challenged by microbial plaque, it is generally maintained in a healthy state. To understand the basis for this, we investigated innate antiviral immunity in human periodontal tissue. The expression of mRNA encoding different antiviral proteins, myxovirus resistance A (MxA), protein kinase R (PKR), oligoadenylate synthetase (OAS), and secretory leukocyte protease inhibitor (SLPI) were detected in both healthy tissue and that with periodontitis. Immunostaining data consistently showed higher MxA protein expression in the epithelial layer of healthy gingiva as compared with tissue with periodontitis. Human MxA is thought to be induced by type I and III interferons (IFNs) but neither cytokine type was detected in healthy periodontal tissues. Treatment in vitro of primary human gingival epithelial cells (HGECs) with α-defensins, but not with the antimicrobial peptides β-defensins or LL-37, led to MxA protein expression. α-defensin was also detected in healthy periodontal tissue. In addition, MxA in α-defensin-treated HGECs was associated with protection against avian influenza H5N1 infection and silencing of the MxA gene using MxA-targeted-siRNA abolished this antiviral activity. To our knowledge, this is the first study to uncover a novel pathway of human MxA induction, which is initiated by an endogenous antimicrobial peptide, namely α-defensin. This pathway may play an important role in the first line of antiviral defense in periodontal tissue. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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    Relative levels of IL4 and IFN-γ in complicated malaria: Association with IL4 polymorphism and peripheral parasitemia
    (2007-03-01) Piyatida Tangteerawatana; Sathit Pichyangkul; Masashi Hayano; Thareerat Kalambaheti; Sornchai Looareesuwan; Marita Troye-Blomberg; Srisin Khusmith; Mahidol University; The Hospital for Tropical Diseases, Bangkok; Armed Forces Research Institute of Medical Sciences, Thailand; Stockholms universitet
    Functional IL4-590 C/T polymorphisms and the relative amounts of IL4 and IFN-γ were investigated in relation to severity of malaria in 110 and 169 Thai patients with complicated and uncomplicated malaria, respectively. The plasma IL4 and IFN-γ levels were determined by ELISA and the IL4-590 C/T polymorphisms were genotyped. The IFN-γ levels were significantly elevated in patients with complicated malaria in the initial stage of the disease before treatment compared to the levels found with uncomplicated malaria (231 pg/ml versus 150 pg/ml, p = 0.0029), while the IL4 levels were significantly elevated 7 days after treatment (167 pg/ml versus 81 pg/ml, p = 0.0003). Our study did not reveal any association between the IL4-590 C/T transition and the severity of malaria. However, a significant difference in the IL4 to IFN-γ ratio between patients with complicated and uncomplicated malaria was observed only in patients with IL4-590 T allele homozygosity (geometric mean: 0.321 versus 0.613, p = 0.0087 for TT allele). A significant inverse correlation between IL4 to IFN-γ ratio and peripheral parasitemia was observed only in complicated malaria patients carrying TT genotype (r = -0.283, p = 0.046). These results suggest that the IL4-590 C/T polymorphism may play a role in the balance between IL4 and IFN-γ, as well as in the control of parasitemia, which in turn may alter the severity of malaria. © 2007.
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    Role of CD34+ hematopoietic stem cells and mesenchymal stromal cells on avian influenza virus (H5N1) pathogenesis
    (Mahidol University. Mahidol University Library and Knowledge Center, 2023) Maytawan Thanunchai; Arunee Thitithanyanont; Prasert Auewarakul; Sathit Pichyangkul
    Avian influenza A H5N1 virus continues to cause a global threat to human health. Major complications of H5N1 infection are the systemic spread with uncontrolled replication and host cytokine responses leading to gross pathology-like sepsis. The clinical data suggests almost half of the fatal cases were associated with hyperactivation of cytokines which might be correlated with reactive hemophagocytosis. Moreover, the presence of abnormal hematologic findings such as lymphopenia, thrombocytopenia, and pancytopenia were diagnosed in severe cases. These increase interest in exploring bone marrow (BM) dissemination, which direct infection of BM cells remains elusive. The BM compartment contains two stem cell types, which are hematopoietic stem cells (HSCs) and mesenchymal stromal cells (MSCs) with possessing stem-like and immunomodulatory properties. Our investigation demonstrated that CD34+ HSCs and MSCs were susceptible to H5N1 infection. H5N1 virus could productively infect and induce cell deaths in both cell types. By contrast, these aspects were not found in human influenza virus infection. Reverse genetics analyses demonstrated that hemagglutinin played a role in the infection of MSCs. We also investigated host response following H5N1 infection of CD34+ HSCs and MSCs. We found that inflammatory cytokines were not induced in H5N1-infected cells. We next investigated whether infection affects the immunomodulatory function of MSCs. We noted a consequent dysregulation of MSCs-mediated immune modulation from high cytokine and chemokine production in H5N1-infected MSCs/Monocytes co-culture. These findings provide a better understanding of H5N1 pathogenesis in terms of host tropism and systemic spread.
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    Short report: Pre-existing cross-reactive antibodies to avian influenza H5N1 and 2009 pandemic H1N1 in US military personnel
    (2014-01-01) Sathit Pichyangkul; Somporn Krasaesub; Anan Jongkaewwattana; Arunee Thitithanyanont; Suwimon Wiboon-ut; Kosol Yongvanitchit; Amporn Limsalakpetch; Utaiwan Kum-Arb; Duangrat Mongkolsirichaikul; Nuanpan Khemnu; Rangsini Mahanonda; Jean Michel Garcia; Carl J. Mason; Douglas S. Walsh; David L. Saunders; Armed Forces Research Institute of Medical Sciences, Thailand; Thailand National Center for Genetic Engineering and Biotechnology; Mahidol University; Chulalongkorn University; HKU-Pasteur Research Centre
    We studied cross-reactive antibodies against avian influenza H5N1 and 2009 pandemic (p) H1N1 in 200 serum samples from US military personnel collected before the H1N1 pandemic. Assays used to measure antibodies against viral proteins involved in protection included a hemagglutination inhibition (HI) assay and a neuraminidase inhibition (NI) assay. Viral neutralization by antibodies against avian influenza H5N1 and 2009 pH1N1 was assessed by influenza (H5) pseudotyped lentiviral particle-based and H1N1 microneutralization assays. Some US military personnel had cross-neutralizing antibodies against H5N1 (14%) and 2009 pH1N1 (16.5%). The odds of having cross-neutralizing antibodies against 2009 pH1N1 were 4.4 times higher in subjects receiving more than five inactivated whole influenza virus vaccinations than those subjects with no record of vaccination. Although unclear if the result of prior vaccination or disease exposure, these pre-existing antibodies may prevent or reduce disease severity. Copyright © 2014 by The American Society of Tropical Medicine and Hygiene.
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    A single injection of 19 kDa carboxy-terminal fragment of Plasmodium yoelii merozoite surface protein 1 (PyMSP1 19) formulated with Montanide ISA and CpG ODN induces protective immune response in mice
    (2011-09-26) Chakrit Hirunpetcharat; Yuvadee Mahakunkijcharoen; Pimmada Jeamwattanalert; Leera Kittigul; Pakpimol Mahannop; Sathit Pichyangkul; Faculty of Public Health; Mahidol University; Armed Forces Research Institute of Medical Sciences, Thailand
    Objective: To investigate the efficacy of a vaccine formulation of the 19 kDa conserved carboxylterminal fragment of Plasmodium yoelii merozoite surface protein-1 (PyMSP1 19 ) formulated with CpG ODN 1826 and Montanide ISA51 or ISA720 when used to immunize mice by a single injection. Methods: Groups of BALB/c mice were immunized parenterally with one, two or four injections with PBS or PyMSP1 19 formulated with CpG ODN in ISA51 or ISA720. Sera were collected weekly and assessed for total IgG and IgG subclass titers. Protection was tested by challenge infection with P. yoelii YM. Results: Interestingly, single injection immunization showed the same kinetics of antibody responses as two-or four-injection immunization. However, the peak antibody response induced by PyMSP1 19 in CpG ODN and ISA51 appeared earlier than that induced by PyMSP1 19 in CpG ODN and ISA720 (28 days vs 41 days). At day 63 after the first injection, the PyMSP1 19 -specific IgG antibody levels by single injection and fourinjection immunizations were not different. However, the levels of the IgG2a antibody subclass were significantly lower by single injection immunization with PyMSP1 19 in CpG ODN and ISA720. The antibodies were sustained at high levels for at least 20 weeks. After challenge infection, all mice immunized by a single injection of PyMSP1 19 in CpG ODN and ISA51 survived with low-grade parasitemia, while 50% of mice immunized with PyMSP1 19 in CpG ODN and ISA720 died with high levels of parasitemia. Conclusion: These findings suggest that MSP119 immunization by a single injection can induce protective immunity, particularly when formulated with an appropriate strong adjuvant.