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Rapid detection, serotyping and quantitation of dengue viruses by TaqMan real-time one-step RT-PCR

Kong YY, Thay CH, Tin TC, Devi S

J Virol Methods, 2006 Dec;138(1-2):123-30.
PMID: 17000012 DOI: 10.1016/j.jviromet.2006.08.003

The use of the polymerase chain reaction (PCR) in molecular diagnosis is now accepted worldwide and has become an essential tool in the research laboratory. In the laboratory, a rapid detection, serotyping and quantitation, one-step real-time RT-PCR assay was developed for dengue virus using TaqMan probes. In this assay, a set of forward and reverse primers were designed targeting the serotype conserved region at the NS5 gene, at the same time flanking a variable region for all four serotypes which were used to design the serotype-specific TaqMan probes. This multiplex one-step RT-PCR assay was evaluated using 376 samples collected during the year 2003. These groups included RNA from prototype dengue virus (1-4), RNA from acute serum from which dengue virus was isolated, RNA from tissue culture supernatants of dengue virus isolated, RNA from seronegative acute samples (which were culture and IgM negative) and RNA from samples of dengue IgM positive sera. The specificity of this assay was also evaluated using a panel of sera which were positive for other common tropical disease agents including herpes simplex virus, cytomegalovirus, measles virus, varicella-zoster virus, rubella virus, mumps virus, WWF, West Nile virus, Japanese encephalitis virus, S. typhi, Legionella, Leptospira, Chlamydia, and Mycoplasma. The sensitivity, specificity and real-time PCR efficiency of this assay were 89.54%, 100% and 91.5%, respectively.
Regulation of CD8+ T-cell cytotoxicity in HIV-1 infection

Saeidi A, Buggert M, Che KF, Kong YY, Velu V, Larsson M, et al.

Cell Immunol, 2015 Nov-Dec;298(1-2):126-33.
PMID: 26520669 DOI: 10.1016/j.cellimm.2015.10.009

Understanding the mechanisms involved in cellular immune responses against control of human immunodeficiency virus (HIV) infection is key to development of effective immunotherapeutic strategies against viral proliferation. Clear insights into the regulation of cytotoxic CD8+ T cells is crucial to development of effective immunotherapeutic strategies due to their unique ability to eliminate virus-infected cells during the course of infection. Here, we reviewed the roles of transcription factors, co-inhibitory molecules and regulatory cytokines following HIV infection and their potential significance in regulating the cytotoxic potentials of CD8+ T cells.
Fulltext The CD14 C-260T single nucleotide polymorphism (SNP) modulates monocyte/macrophage activation in treated HIV-infected individuals

Rajasuriar R, Kong YY, Nadarajah R, Abdullah NK, Spelman T, Yuhana MY, et al.

J Transl Med, 2015;13:30.
PMID: 25622527 DOI: 10.1186/s12967-015-0391-6

HIV-infected individuals have an increased risk of cardiovascular disease (CVD). T-allele carriers of the CD14 C-260T single-nucleotide polymorphism (SNP) have reported increased expression of the LPS-binding receptor, CD14 and inflammation in the general population. Our aim was to explore the relationship of this SNP with monocyte/macrophage activation and inflammation and its association with sub-clinical atherosclerosis in HIV-infected individuals.
Diminished Co-inhibitory Molecule 2B4 expression is Associated with Preserved iNKT cell Phenotype in HIV Long-term Non-progressors

Ansari AW, Ahmad F, Shankar EM, Kong YY, Tan HY, Jacobs R, et al.

J Acquir Immune Defic Syndr, 2020 May 07.
PMID: 32398557 DOI: 10.1097/QAI.0000000000002399

BACKGROUND: We have previously shown an association of elevated co-inhibitory molecule 2B4 expression with iNKT cells alterations in HIV disease. Herein we show a comparative analysis of 2B4 expression on iNKT cells of HIV long-term non-progressors (LTNPs) and progressors.
METHODS: Anti-retroviral therapy (ART) naïve HIV-seropositive individuals (progressors, n=16) and long-term non-progressors (LTNPs, n=10) were recruited for this study. We employed multi-color flow cytometry on frozen peripheral blood mononuclear cells (PBMCs) to determine iNKT subset frequencies, the levels of co-inhibitory 2B4 expression, and intracellular IFN-γ production. CD1d tetramer was used to characterize iNKT cells.
RESULTS: We report significantly lower level of 2B4 expression on bulk LTNPs iNKT cells as well as on their CD4 subsets compared to HIV progressors. Furthermore, the iNKT cells from LTNPs produced higher amount of IFN-γ than HIV progressors as detected by intracellular cytokine staining. Interestingly, the frequency of 2B4iNKT cells of progressors but not LTNPs significantly correlates with CD4 T cell count, HIV viral load and IFNγ production by iNKT cells.
CONCLUSION: Our results suggest that in addition to suppressed HIV replication, diminished 2B4 expression and associated co-inhibitory signaling, and substantial production of IFN-γ could contribute to preserved iNKT cell phenotype in LTNPs.