Displaying publications 161 - 180 of 2094 in total

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  1. Xu X, Yi C, Feng T, Ge Y, Liu M, Wu C, et al.
    Clin Immunol, 2023 Aug;253:109685.
    PMID: 37406980 DOI: 10.1016/j.clim.2023.109685
    Inducing tumor-specific T cell responses and regulating suppressive tumor microenvironments have been a challenge for effective tumor therapy. CpG (ODN), the Toll-like receptor 9 agonist, has been widely used as adjuvants of cancer vaccines to induce T cell responses. We developed a novel adjuvant to improve the targeting of lymph nodes. CpG were modified with lipid and glycopolymers by the combination of photo-induced RAFT polymerization and click chemistry, and the novel adjuvant was termed as lipid-glycoadjuvant@AuNPs (LCpG). OVA protein was used as model antigen and melanoma model was established to test the immunotherapy effect of the adjuvant. In tumor model, the antitumor effect and mechanism of LCpG on the response of CTLs were examined by flow cytometry and cell cytotoxicity assay. The effects of LCpG on macrophage polarization and Tregs differentiation in tumor microenvironment were also studied by cell depletion assay and cytokine neutralization assay. We also tested the therapeutic effect of the combination of the adjuvant and anti-PD-1 treatment. LCpG could be rapidly transported to and retained longer in the lymphoid nodes than unmodified CpG. In melanoma model, LCpG controlled both primary tumor and its metastasis, and established long-term memory. In spleen and tumor draining lymphoid nodes, LCpG activated tumor-specific Tc1 responses, with increased CD8+ T-cell proliferation, antigen-specific Tc1 cytokine production and specific-tumor killing capacity. In tumor microenvironments, antigen-specific Tc1 induced by the LCpG promoted CTL infiltration, skewed tumor associated macrophages to M1 phenotype, regulated Treg and induced proinflammatory cytokines production in a CTL-derived IFN-γ-dependent manner. In vivo cell depletion and adoptive transfer experiments confirmed that antitumor activity of LCpG included vaccine was mainly dependent on CTL-derived IFN-γ. The anti-tumor efficacy of LCpG was dramatically enhanced when combined with anti-PD1 immunotherapy. LCpG was a promising adjuvant for vaccine formulation which could augment tumor-specific Tc1 activity, and regulate tumor microenvironments.
    Matched MeSH terms: Mice, Inbred C57BL; Mice
  2. Xiong C, Zou X, Phan CW, Huang W, Zhu Y
    Biosci Rep, 2024 Mar 29;44(3).
    PMID: 38391133 DOI: 10.1042/BSR20231807
    Rapeseed cake serves as a by-product in the oil extraction industry, characterized by its elevated protein content. However, the presence of antinutritional factors limits the utilization of rapeseed cake as a viable protein source. In this study, different doses of γ-irradiation were used to irradiate rapeseed cake and rapeseed protein isolate was extracted through a modified alkaline solution and acid precipitation method from rapeseed cake. The chemical composition and in vivo acute toxicity of rapeseed protein isolate were determined. The protein recovery rate of rapeseed protein isolate was 39.08 ± 3.01% after irradiation, while the content of antinutritional factors was significantly reduced. Moreover, γ-irradiation did not have any experimentally related effects on clinical observations or clinicopathology in mice. Overall, the reduced antinutrients and increased functional properties suggest that the irradiation of rapeseed cake (<9 kGy) could be utilized as a pre-treatment in the development of rapeseed cake-based value-added protein products.
    Matched MeSH terms: Mice
  3. Xin GLL, Khee YP, Ying TY, Chellian J, Gupta G, Kunnath AP, et al.
    Curr. Diab. Rep., 2019 03 23;19(5):22.
    PMID: 30905013 DOI: 10.1007/s11892-019-1144-3
    PURPOSE OF REVIEW: Type 1 diabetes (T1D) occurs when there is destruction of beta cells within the islets of Langerhans in the pancreas due to autoimmunity. It is considered a complex disease, and different complications can surface and worsen the condition if T1D is not managed well. Since it is an incurable disease, numerous treatments and therapies have been postulated in order to control T1D by balancing hyperglycemia control while minimizing hypoglycemic episodes. The purpose of this review is to primarily look into the current state of the available immunological therapies and their advantages for the treatment of T1D.

    RECENT FINDINGS: Over the years, immunological therapy has become the center of attraction to treat T1D. Immunomodulatory approaches on non-antigens involving agents such as cyclosporine A, mycophenolate mofetil, anti-CD20, cytotoxic T cells, anti-TNF, anti-CD3, and anti-thymocyte globulin as well as immunomodulative approaches on antigens such as insulin, glutamic acid decarboxylase, and heat shock protein 60 have been studied. Aside from these two approaches, studies and trials have also been conducted on regulatory T cells, dendritic cells, interleukin 2, interleukin 4, M2 macrophages, and rapamycin/interleukin 2 combination therapy to test their effects on patients with T1D. Many of these agents have successfully suppressed T1D in non-obese diabetic (NOD) mice and in human trials. However, some have shown negative results. To date, the insights into the management of the immune system have been increasing rapidly to search for potential therapies and treatments for T1D. Nevertheless, some of the challenges are still inevitable. A lot of work and effort need to be put into the investigation on T1D through immunological therapy, particularly to reduce complications to improve and enhance clinical outcomes.

    Matched MeSH terms: Mice, Inbred NOD
  4. Xian TH, Sinniah K, Yean CY, Krishnamoorthy V, Bahari MB, Ravichandran M, et al.
    BMC Immunol, 2020 05 25;21(1):29.
    PMID: 32450807 DOI: 10.1186/s12865-020-00360-1
    BACKGROUND: Cholera, an acute watery diarrhoeal disease caused by Vibrio cholerae serogroup O1 and O139 across the continents. Replacing the existing WHO licensed killed multiple-dose oral cholera vaccines that demand 'cold chain supply' at 2-8 °C with a live, single-dose and cold chain-free vaccine would relieve the significant bottlenecks and cost determinants in cholera vaccination campaigns. In this direction, a prototype cold chain-free live attenuated cholera vaccine formulation (LACV) was developed against the toxigenic wild-type (WT) V. cholerae O139 serogroup. LACV was found stable and retained its viability (5 × 106 CFU/mL), purity and potency at room temperature (25 °C ± 2 °C, and 60% ± 5% relative humidity) for 140 days in contrast to all the existing WHO licensed cold-chain supply (2-8 °C) dependent killed oral cholera vaccines.

    RESULTS: The LACV was evaluated for its colonization potential, reactogenicity, immunogenicity and protective efficacy in animal models after its storage at room temperature for 140 days. In suckling mice colonization assay, the LACV recorded the highest recovery of (7.2 × 107 CFU/mL) compared to those of unformulated VCUSM14P (5.6 × 107 CFU/mL) and the WT O139 strain (3.5 × 107 CFU/mL). The LACV showed no reactogenicity even at an inoculation dose of 104-106 CFU/mL in a rabbit ileal loop model. The rabbits vaccinated with the LACV or unformulated VCUSM14P survived a challenge with WT O139 and showed no signs of diarrhoea or death in the reversible intestinal tie adult rabbit diarrhoea (RITARD) model. Vaccinated rabbits recorded a 275-fold increase in anti-CT IgG and a 15-fold increase in anti-CT IgA antibodies compared to those of rabbits vaccinated with unformulated VCUSM14P. Vibriocidal antibodies were increased by 31-fold with the LACV and 14-fold with unformulated VCUSM14P.

    CONCLUSION: The vaccine formulation mimics a natural infection, is non-reactogenic and highly immunogenic in vivo and protects animals from lethal wild-type V. cholerae O139 challenge. The single dose LACV formulation was found to be stable at room temperature (25 ± 2 °C) for 140 days and it would result in significant cost savings during mass cholera vaccination campaigns.

    Matched MeSH terms: Mice, Inbred BALB C; Mice
  5. Xia NB, Lu Y, Zhao PF, Wang CF, Li YY, Tan L, et al.
    Trop Biomed, 2020 Jun 01;37(2):489-498.
    PMID: 33612818
    Toxoplasma gondii, a ubiquitous pathogen that infects nearly all warm-blooded animals and humans, can cause severe complications to the infected people and animals as well as serious economic losses and social problems. Here, one local strain (TgPIG-WH1) was isolated from an aborted pig fetus, and the genotype of this strain was identified as ToxoDB #3 by the PCR RFLP typing method using 10 molecular markers (SAG1, SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, C22-8, C29-2 and Apico). A comparison of the virulence of this isolate with other strains in both mice and piglets showed that TgPIG-WH1 was less virulent than type 1 strain RH and type 2 strain ME49 in mice, and caused similar symptoms to those of ME49 such as fever in piglets. Additionally, in piglet infection with both strains, the TgPIG-WH1 caused a higher IgG response and more severe pathological damages than ME49. Furthermore, TgPIG-WH1 caused one death in the 5 infected piglets, whereas ME49 did not, suggesting the higher virulence of TgPIG-WH1 than ME49 during piglet infection. Experimental infections indicate that the virulence of TgPIG-WH1 relative to ME49 is weaker in mice, but higher in pigs. This is probably the first report regarding a ToxoDB #3 strain from pigs in Hubei, China. These data will facilitate the understanding of genetic diversity of Toxoplasma strains in China as well as the prevention and control of porcine toxoplasmosis in the local region.
    Matched MeSH terms: Mice
  6. Wu YX, Kim YJ, Kwon TH, Tan CP, Son KH, Kim T
    Nat Prod Res, 2020 Jun;34(12):1786-1790.
    PMID: 30470128 DOI: 10.1080/14786419.2018.1527832
    Mulberry (Morus alba L.) root bark (MRB) was extracted using methanol and the extracts were subjected to tests of anti-inflammatory effects. The ethyl acetate fraction demonstrated the best anti-inflammatory effects. Purified compounds, sanggenon B, albanol B and sanggenon D, showed inhibitory effects on NO production in LPS-stimulated RAW264.7 cells and albanol B demonstrated the best anti-inflammatory effects. Regarding the underlying molecular mechanisms, further investigations showed that treatments with Albanol B reduced production of pro-inflammatory cytokines and decreased expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). These results would contribute to development of novel anti-inflammatory drugs from MRB.
    Matched MeSH terms: Mice
  7. Wu X, Zhang S, Lai J, Lu H, Sun Y, Guan W
    Exp Clin Transplant, 2020 12;18(7):823-831.
    PMID: 33349209 DOI: 10.6002/ect.2020.0108
    OBJECTIVES: Liver fibrosis is inevitable in the healing process of liver injury. Liver fibrosis will develop into liver cirrhosis unless the damaging factors are removed. This study investigated the potential therapy of Bama pig adipose-derived mesenchymal stem cells in a carbon tetrachloride-induced liver fibrosis Institute of Cancer Research strain mice model.

    MATERIALS AND METHODS: Adipose-derived mesenchymal stem cells were injected intravenously into the tails of mice of the Institute of Cancer Research strain that had been treated with carbon tetrachloride for 4 weeks. Survival rate, migration, and proliferation of adipose-derived mesenchymal stem cells in the liver were observed by histochemistry, fluorescent labeling, and serological detection.

    RESULTS: At 1, 2, and 3 weeks after adipose-derived mesenchymal stem cell injection, liver fibrosis was significantly ameliorated. The injected adipose-derived mesenchymal stem cells had hepatic differentiation potential in vivo, and the survival rate of adipose-derived mesenchymal stem cells declined over time.

    CONCLUSIONS: The findings in this study confirmed that adipose-derived mesenchymal stem cells derived from the Bama pig can be used in the treatment of liver fibrosis, and the grafted adipose-derived mesenchy-mal stem cells can migrate, survive, and differentiate into hepatic cells in vivo.

    Matched MeSH terms: Mice, Inbred ICR
  8. Wu LE, Meoli CC, Mangiafico SP, Fazakerley DJ, Cogger VC, Mohamad M, et al.
    Diabetes, 2014 Aug;63(8):2656-67.
    PMID: 24696450 DOI: 10.2337/db13-1665
    The vascular endothelial growth factor (VEGF) family of cytokines are important regulators of angiogenesis that have emerged as important targets for the treatment of obesity. While serum VEGF levels rise during obesity, recent studies using genetic models provide conflicting evidence as to whether VEGF prevents or accelerates metabolic dysfunction during obesity. In the current study, we sought to identify the effects of VEGF-A neutralization on parameters of glucose metabolism and insulin action in a dietary mouse model of obesity. Within only 72 h of administration of the VEGF-A-neutralizing monoclonal antibody B.20-4.1, we observed almost complete reversal of high-fat diet-induced insulin resistance principally due to improved insulin sensitivity in the liver and in adipose tissue. These effects were independent of changes in whole-body adiposity or insulin signaling. These findings show an important and unexpected role for VEGF in liver insulin resistance, opening up a potentially novel therapeutic avenue for obesity-related metabolic disease.
    Matched MeSH terms: Mice
  9. Wu JY, Ooi CW, Song CP, Wang CY, Liu BL, Lin GY, et al.
    Carbohydr Polym, 2021 Jun 15;262:117910.
    PMID: 33838797 DOI: 10.1016/j.carbpol.2021.117910
    N-[(2-hydroxyl-3-trimethylammonium) propyl] chitosan chloride (HTCC), which is a type of chitosan derivative with quaternary ammonium groups, possesses a higher antibacterial activity as compared to the pristine chitosan. The nanofiber membranes made of HTCC are attractive for applications demanding for antibacterial function. However, the hydrophilic nature of HTCC makes it unsuitable for electrospinning of nanofibers. Hence, biodegradable polyvinyl alcohol (PVA) was proposed as an additive to improve the electrospinnability of HTCC. In this work, PVA/HTCC nanofiber membrane was crosslinked with the blocked diisocyanate (BI) to enhance the stability of nanofiber membrane in water. Microbiological assessments showed that the PVA/HTCC/BI nanofiber membranes possessed a good antibacterial efficacy (∼100 %) against E. coli. Moreover, the biocompatibility of PVA/HTCC/BI nanofiber membrane was proven by the cytotoxicity test on mouse fibroblasts. These promising results indicated that the PVA/HTCC/BI nanofiber membrane can be a promising material for food packaging and as a potential wound dressing for skin regeneration.
    Matched MeSH terms: Mice
  10. Wu HT, Lin YT, Chew SH, Wu KJ
    Biomed J, 2023 Feb;46(1):122-133.
    PMID: 35183794 DOI: 10.1016/j.bj.2022.02.002
    BACKGROUND: K63-linked polyubiquitination of proteins have nonproteolytic functions and regulate the activity of many signal transduction pathways. USP7, a HIF1α deubiquitinase, undergoes K63-linked polyubiquitination under hypoxia. K63-polyubiquitinated USP7 serves as a scaffold to anchor HIF1α, CREBBP, the mediator complex, and the super elongation complex to enhance HIF1α-induced gene transcription. However, the physiological role of K63-polyubiquitinated USP7 remains unknown.

    METHODS: Using a Usp7K444R point mutation knock-in mouse strain, we performed immunohistochemistry and standard molecular biological methods to examine the organ defects of liver and kidney in this knock-in mouse strain. Mechanistic studies were performed by using deubiquitination, immunoprecipitation, and quantitative immunoprecipitations (qChIP) assays.

    RESULTS: We observed multiple organ defects, including decreased liver and muscle weight, decreased tibia/fibula length, liver glycogen storage defect, and polycystic kidneys. The underlying mechanisms include the regulation of protein stability and/or modulation of transcriptional activation of several key factors, leading to decreased protein levels of Prr5l, Hnf4α, Cebpα, and Hnf1β. Repression of these crucial factors leads to the organ defects described above.

    CONCLUSIONS: K63-polyubiquitinated Usp7 plays an essential role in the development of multiple organs and illustrates the importance of the process of K63-linked polyubiquitination in regulating critical protein functions.

    Matched MeSH terms: Mice, Mutant Strains; Mice
  11. Woon SM, Seng YW, Ling AP, Chye SM, Koh RY
    J Zhejiang Univ Sci B, 2014 Mar;15(3):295-302.
    PMID: 24599694 DOI: 10.1631/jzus.B1300123
    This study examined the anti-adipogenic effects of extracts of Ficus deltoidea var. deltoidia and var. angustifolia, a natural slimming aid, on 3T3-L1 adipocytes.
    Matched MeSH terms: Mice
  12. Woodruff DS, Merenlender AM, Upatham ES, Viyanant V
    Am J Trop Med Hyg, 1987 Mar;36(2):345-54.
    PMID: 3826494
    Electrophoretically-detected allozyme variation is described in strains of Schistosoma japonicum (4 Philippine strains), S. mekongi (Laos), and an undescribed anthropophilic S. japonicum-like schistosome from Peninsular Malaysia. Result, together with those reported previously for 8 other strains (S. japonicum, China, Formosa, Japan, Philippines; S. mekongi, 2 substrains; Malaysian schistosome, 2 strains) permit a composite genetic characterization of 15 strains of Asian schistosomes at 9-18 presumptive loci. The proportion of polymorphic loci (P) and the mean heterozygosity per locus (H) were zero in all strains. Although this was expected for strains that had been in laboratory culture for up to 50 years, we expected to detect variation in strains based on 10-50 recently field-collected infected snails. We expected S. japonicum to be as variable as S. mansoni (P = 0.13 (0-0.33), H = 0.04, 18 loci, 22 strains) as it is believed to reproduce sexually, has an evolutionary history of several million years, inhabits a wide geographic range, coevolved with a genetically variable intermediate snail host, and has a diversity of mammalian hosts. No differences were detected between the 5 S. japonicum strains from Leyte and Luzon (Philippines), between the 3 S. mekongi strains, or between the 3 Malaysian schistosome strains; these groups and the remaining S. japonicum strains representing Mindoro (Philippines), China, Formosa, and Japan each have distinctive multilocus electromorphic patterns. Nei's genetic distances (D) were calculated to estimate interstrain and interspecific divergence. Interstrain genetic distances in S. japonicum averaged greater than 0.3; much higher than those reported previously for S. mansoni (D = 0.06, D(max) = 0.24). S. japonicum (Mindoro) was moderately differentiated from the Leyte-Luzon strains (D = 0.29, 12 loci). Estimates of the S. japonicum China-Philippine distance (D greater than 0.4, 11 loci) are high for conspecific populations and further studies of the still poorly characterized Chinese parasite may reveal that these are, in fact, separate species. S. japonicum is shown to be only distantly related to S. mekongi and the Malaysian schistosome (D greater than 1); the latter is closely related to, but genetically quite distinct from, S. mekongi (D = 0.61 +/- 0.275, 11 loci) and warrants recognition as a new species. The medical significance of the isogenic nature of the Asian schistosome strains and their evolutionary divergence are discussed.
    Matched MeSH terms: Mice
  13. Wongrattanakamon P, Lee VS, Nimmanpipug P, Sirithunyalug B, Chansakaow S, Jiranusornkul S
    Toxicol. Mech. Methods, 2017 May;27(4):253-271.
    PMID: 27996361 DOI: 10.1080/15376516.2016.1273428
    In this work, molecular docking, pharmacophore modeling and molecular dynamics (MD) simulation were rendered for the mouse P-glycoprotein (P-gp) (code: 4Q9H) and bioflavonoids; amorphigenin, chrysin, epigallocatechin, formononetin and rotenone including a positive control; verapamil to identify protein-ligand interaction features including binding affinities, interaction characteristics, hot-spot amino acid residues and complex stabilities. These flavonoids occupied the same binding site with high binding affinities and shared the same key residues for their binding interactions and the binding region of the flavonoids was revealed that overlapped the ATP binding region with hydrophobic and hydrophilic interactions suggesting a competitive inhibition mechanism of the compounds. Root mean square deviations (RMSDs) analysis of MD trajectories of the protein-ligand complexes and NBD2 residues, and ligands pointed out these residues were stable throughout the duration of MD simulations. Thus, the applied preliminary structure-based molecular modeling approach of interactions between NBD2 and flavonoids may be gainful to realize the intimate inhibition mechanism of P-gp at NBD2 level and on the basis of the obtained data, it can be concluded that these bioflavonoids have the potential to cause herb-drug interactions or be used as lead molecules for the inhibition of P-gp (as anti-multidrug resistance agents) via the NBD2 blocking mechanism in future.
    Matched MeSH terms: Mice
  14. Wong YC, Naeem R, Abd El Ghany M, Hoh CC, Pain A, Nathan S
    Front Cell Infect Microbiol, 2022;12:1062682.
    PMID: 36619746 DOI: 10.3389/fcimb.2022.1062682
    INTRODUCTION: Burkholderia pseudomallei, a soil-dwelling microbe that infects humans and animals is the cause of the fatal disease melioidosis. The molecular mechanisms that underlie B. pseudomallei's versatility to survive within a broad range of environments are still not well defined.

    METHODS: We used the genome-wide screening tool TraDIS (Transposon Directed Insertion-site Sequencing) to identify B. pseudomallei essential genes. Transposon-flanking regions were sequenced and gene essentiality was assessed based on the frequency of transposon insertions within each gene. Transposon mutants were grown in LB and M9 minimal medium to determine conditionally essential genes required for growth under laboratory conditions. The Caenorhabditis elegans infection model was used to assess genes associated with in vivo B. pseudomallei survival. Transposon mutants were fed to the worms, recovered from worm intestines, and sequenced. Two selected mutants were constructed and evaluated for the bacteria's ability to survive and proliferate in the nematode intestinal lumen.

    RESULTS: Approximately 500,000 transposon-insertion mutants of B. pseudomallei strain R15 were generated. A total of 848,811 unique transposon insertion sites were identified in the B. pseudomallei R15 genome and 492 genes carrying low insertion frequencies were predicted to be essential. A total of 96 genes specifically required to support growth under nutrient-depleted conditions were identified. Genes most likely to be involved in B. pseudomallei survival and adaptation in the C. elegans intestinal lumen, were identified. When compared to wild type B. pseudomallei, a Tn5 mutant of bpsl2988 exhibited reduced survival in the worm intestine, was attenuated in C. elegans killing and showed decreased colonization in the organs of infected mice.

    DISCUSSION: The B. pseudomallei conditional essential proteins should provide further insights into the bacteria's niche adaptation, pathogenesis, and virulence.

    Matched MeSH terms: Mice
  15. Wong WF, Kohu K, Nagashima T, Funayama R, Matsumoto M, Movahed E, et al.
    Mol Immunol, 2015 Dec;68(2 Pt A):223-33.
    PMID: 26350416 DOI: 10.1016/j.molimm.2015.08.012
    The Runx1 transcription factor cooperates with or antagonizes other transcription factors and plays essential roles in the differentiation and function of T lymphocytes. Previous works showed that Runx1 is expressed in peripheral CD4(+) T cells which level declines after T cell receptor (TCR) activation, and artificial deletion of Runx1 causes autoimmune lung disease in mice. The present study addresses the mechanisms by which Runx1 contributes to the maintenance of peripheral CD4(+) T cell quiescence. Microarray and quantitative RT-PCR analyses were employed to compare the transcriptome of Runx1 -/- CD4(+) T cells to those of unstimulated and TCR-stimulated Runx1 +/- cells. The results identified genes whose expression was modulated similarly by Runx1 deletion and TCR activation. Among them, genes encoding cytokines, chemokines, and Jak/STAT signaling molecules were substantially induced. In Runx1-deleted T cells, simultaneous increases in Il-17A and Rorγc, a known master gene in TH17 differentiation, were observed. In addition, we observed that the loss of Runx1 reduced the transcription of genes encoding quiescence-associated transcription factors, including Foxp1, Foxo1, and Klf2. Interestingly, we identified consensus Runx1 binding sites at the promoter regions of Foxp1, Foxo1, and Klf2 genes, which can be enriched by chromatin immunoprecipitation assay with an anti-Runx1 antibody. Therefore, we suggest that Runx1 may activate, directly or indirectly, the expression of quiescence-associated molecules and thereby contribute to the maintenance of quiescence in CD4(+) T cells.
    Matched MeSH terms: Mice, Transgenic; Mice
  16. Wong WF, Looi CY, Kon S, Movahed E, Funaki T, Chang LY, et al.
    Eur J Immunol, 2014 Mar;44(3):894-904.
    PMID: 24310293 DOI: 10.1002/eji.201343496
    Runx1 transcription factor is a key player in the development and function of T cells. Runx1 transcripts consist of two closely related isoforms (proximal and distal Runx1) whose expressions are regulated by different promoters. Which Runx1 isoform is expressed appears to be tightly regulated. The regulatory mechanism for differential transcription is, however, not fully understood. In this study, we investigated the regulation of the proximal Runx1 promoter in T cells. We showed that proximal Runx1 was expressed at a low level in naïve T cells from C57BL/6 mice, but its expression was remarkably induced upon T-cell activation. In the promoter of proximal Runx1, a highly conserved region was identified which spans from -412 to the transcription start site and harbors a NFAT binding site. In a luciferase reporter assay, this region was found to be responsive to T-cell activation through Lck and calcineurin pathways. Mutagenesis studies and chromatin immunoprecipitation assay indicated that the NFAT site was essential for NFAT binding and transactivation of the proximal Runx1 promoter. Furthermore, TCR signaling-induced expression of proximal Runx1 was blocked by treatment of cells with cyclosporin A. Together, these results demonstrate that the calcineurin-NFAT pathway regulates proximal Runx1 transcription upon TCR stimulation.
    Matched MeSH terms: Mice
  17. Wong SS, Abd-Jamil J, Abubakar S
    Viral Immunol, 2007 Sep;20(3):359-68.
    PMID: 17931106
    Outbreaks involving dengue viruses (DENV) of the same genotype occur in a cyclical pattern in Malaysia. Two cycles of outbreaks involving dengue virus type 2 (DENV-2) of the same genotype occurred in the 1990s in the Klang Valley, Malaysia. Sera of patients from the first outbreak and sera of mice inoculated with virus from the same outbreak had poorer neutralization activity against virus of the second outbreak. Conversely, patient sera from the second outbreak showed higher neutralization titer against virus of the early outbreak. At subneutralizing concentrations, sera of mice immunized with second outbreak virus did not significantly enhance infection with viruses from the earlier outbreak. Amino acid substitution from valine to isoleucine at position 129 of the envelope protein (E), as well as threonine to alanine at position 117 and lysine to arginine at position 272 of the NS1 protein, differentiated viruses of the two outbreaks. These findings highlight the potential influence of specific intragenotypic variations in eliciting varied host immune responses against the different DENV subgenotypes. This could be an important contributing factor in the recurring homogenotypic dengue virus outbreaks seen in dengue-endemic regions.
    Matched MeSH terms: Mice
  18. Wong SF, Mak JW
    Hybridoma (Larchmt), 2010 Dec;29(6):539-46.
    PMID: 21117988 DOI: 10.1089/hyb.2010.0049
    Candida parapsilosis has emerged as one of the most common causes of bloodstream infection worldwide. The diagnosis of invasive candidiasis etiological agents to the species level remains a laboratory and clinical challenge. Thus, specific monoclonal antibodies to detect systemic candidiasis and to identify Candida virulence factors and associated pathogenesis through immunohistochemistry would be very useful. Inbred Balb/c mice were immunized with C. parapsilosis antigens, and blood was checked for the presence of reactive antibodies using ELISA. Fusion was performed using the harvested spleen cells and NS1 myeloma cells, and the clones were screened for the presence of antibody producing hybrid cells by dot-blot. The 1B11 clone secreted IgG2a monoclonal antibody that was reactive with the C. parapsilosis antigen at MW of 59 kDa and cross-reacted with C. tropicalis but not with other fungal and bacterial antigens tested. Another 3D1 clone secreted IgG1 monoclonal antibody that was reactive with C. parapsilosis antigen at MW of 30 kDa. The 3D1 monoclonal antibody was found to be species specific. Experimental systemic candidiasis in rats was induced through intravenous injection of C. parapsilosis, and all the vital organs were collected for immunohistochemistry study. These monoclonal antibodies were reactive against surface epitopes on the yeast cells, pseudohyphae, and immune complexes in tissue sections. Sandwich ELISAs using these antibodies were developed and were able to detect circulating antigens in experimental candidiasis in rats at 0.2 μg/μL. These monoclonal antibodies may have potential as primary capture antibodies for the development of rapid diagnostic test for human systemic fungal infection.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  19. Wong SF, Mak JW, Pook CK
    Hybridoma (Larchmt), 2008 Oct;27(5):361-73.
    PMID: 18823263 DOI: 10.1089/hyb.2008.0021
    The Candida species are the most common fungal pathogens of systemic candidiasis. The diagnosis of invasive candidiasis remains a laboratory and clinical challenge. Thus, development of diagnostic assays to detect systemic candidiasis and to identify Candida virulence factors and associated pathogenesis through immunohistochemistry using specific monoclonals and polyclonals will be useful. Inbred Balb/c mice were immunized with C. albicans antigens, and blood was checked for the presence of reactive antibodies using ELISA. Fusion was performed using the harvested spleen cells and NS1 myeloma cells, and the clones were screened for the presence of antibody producing hybrid cells by dot-blot. Western blot analysis showed that the L2D10 monoclonal antibody was reactive against the antigens with molecular weight of 20 kDa. Experimental systemic candidiasis in mice was induced through intravenous injection of C. albicans and all the vital organs were collected for immunohistochemistry study. The monoclonal antibody reacted to surface epitopes on the yeast cells, germ tubes, and hyphae, and to immune complexes. It was used with the polyclonal antibody in a sandwich ELISA for the detection of circulating antigens in experimental candiadiasis in mice. Antibody levels were also determined using the ELISA method, and the antibody levels of C. albicans infected mice were increased compared with uninfected animals. The monoclonal antibody was used in immunoperoxidase and immunofluorescence techniques for the detection of fungal infection in tissue sections and was found to be more sensitive than conventional periodic acid Schiff or silver staining techniques. This monoclonal antibody may serve as potential primary capture antibodies for the development of a rapid diagnostic test for human systemic fungal infection.
    Matched MeSH terms: Mice, Inbred BALB C; Mice
  20. Wong RS
    J Biomed Biotechnol, 2011;2011:459510.
    PMID: 21822372 DOI: 10.1155/2011/459510
    Mesenchymal stem cells (MSCs) have been used in cell-based therapy in various disease conditions such as graft-versus-host and heart diseases, osteogenesis imperfecta, and spinal cord injuries, and the results have been encouraging. However, as MSC therapy gains popularity among practitioners and researchers, there have been reports on the adverse effects of MSCs especially in the context of tumour modulation and malignant transformation. These cells have been found to enhance tumour growth and metastasis in some studies and have been related to anticancer-drug resistance in other instances. In addition, various studies have also reported spontaneous malignant transformation of MSCs. The mechanism of the modulatory behaviour and the tumorigenic potential of MSCs, warrant urgent exploration, and the use of MSCs in patients with cancer awaits further evaluation. However, if MSCs truly play a role in tumour modulation, they can also be potential targets of cancer treatment.
    Matched MeSH terms: Mice
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