Displaying publications 1 - 20 of 23 in total

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  1. 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.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology*
  2. Pang T, Devi S, Blanden RV, Lam SK
    Microbiol. Immunol., 1988;32(5):511-8.
    PMID: 3262810 DOI: 10.1111/j.1348-0421.1988.tb01411.x
    A cytotoxic T lymphocyte (CTL) response to dengue virus-infected target cells is described. Effector cells were generated in an in vitro secondary culture and appeared to be T cells possessing both the Lyt 1.1 and Lyt 2.1 surface antigens. A stronger CTL response was noted with the H-2k haplotype compared to H-2d, and H-2 compatibility was required between CTL and target cells. CTL generated showed some cross-reactivity with target cells infected with Japanese encephalitis virus (JEV), another flavivirus, but not with target cells infected with an alphavirus, Sindbis. The significance and importance of these findings are discussed.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology*
  3. Chai SJ, Yap YY, Foo YC, Yap LF, Ponniah S, Teo SH, et al.
    PLoS One, 2015;10(11):e0130464.
    PMID: 26536470 DOI: 10.1371/journal.pone.0130464
    Nasopharyngeal carcinoma (NPC) is highly prevalent in South East Asia and China. The poor outcome is due to late presentation, recurrence, distant metastasis and limited therapeutic options. For improved treatment outcome, immunotherapeutic approaches focusing on dendritic and autologous cytotoxic T-cell based therapies have been developed, but cost and infrastructure remain barriers for implementing these in low-resource settings. As our prior observations had found that four-jointed box 1 (FJX1), a tumor antigen, is overexpressed in NPCs, we investigated if short 9-20 amino acid sequence specific peptides matching to FJX1 requiring only intramuscular immunization to train host immune systems would be a better treatment option for this disease. Thus, we designed 8 FJX1-specific peptides and implemented an assay system to first, assess the binding of these peptides to HLA-A2 molecules on T2 cells. After, ELISPOT assays were used to determine the peptides immunogenicity and ability to induce potential cytotoxicity activity towards cancer cells. Also, T-cell proliferation assay was used to evaluate the potential of MHC class II peptides to stimulate the expansion of isolated T-cells. Our results demonstrate that these peptides are immunogenic and peptide stimulated T-cells were able to induce peptide-specific cytolytic activity specifically against FJX1-expressing cancer cells. In addition, we demonstrated that the MHC class II peptides were capable of inducing T-cell proliferation. Our results suggest that these peptides are capable of inducing specific cytotoxic cytokines secretion against FJX1-expressing cancer cells and serve as a potential vaccine-based therapy for NPC patients.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/cytology; T-Lymphocytes, Cytotoxic/immunology; T-Lymphocytes, Cytotoxic/metabolism
  4. Fauzah Abd Ghani, Reena Rehavu Zin, Maha Abdullah, Norhafizah Mohtarrudin, Ebenyi Emeka Onwe
    MyJurnal
    Introduction: It is well known that cancer cells evade the immune system with the help of programmed cell death protein 1 (PD-L1) molecule to remain undetected, causing abnormal proliferation of T-cells. PD-L1 expression on the surface of neoplastic cells inhibits cytotoxic T-cell responses which lead to negative regulation of cytokines and proliferation of T-cells. The deleted in colorectal cancer (DCC) gene belongs to the immunoglobulin superfamily. It is a candidate of the tumour suppressor gene by regulating apoptosis. DCC assessment gives an insight into progno-sis in patients with advanced stages of CRC. Thymidylate synthase (TYMS) is a highly conserved enzyme involved in DNA synthesis. TYMS has been an important target for cancer chemotherapy because of its central, rate-limiting role in de novo synthesis of thymidylate. Expression of PD-L1, TYMS and DCC has been demonstrated to confer a prognostic value in CRC but none have been completely validated for patient care. This study aimed to determine the prognostic and predictive potential of PD-L1, TYMS, and DCC biomarkers in CRC. Methods: The expression of these biomarkers was evaluated immunohistochemically in 91 formalin-fixed paraffin-embedded (FFPE) archival tumour samples from patients that underwent surgical resection. Results: There was high expression of DCC in most cases; 84.6% (77/91). TYMS expression at a high level score was 46.2% (42/91) and at low level was 53.8% (49/91). Majority of cases had low PD-L1 expression in 93.4% (86/91) cases and high expression was detected in 6.6% (6/94) of cases. In addition, there was a significant association between TYMS expression with gender (P < 0.05) with distribution of TYMS expression detected at high level was 76.2% in male and 23.8% in female. The Kaplan-Meier survival plot showed mean overall survival in patients with PD-L1 with high expression to be 22 months, which pre-dicts better survival. TYMS low expression showed mean overall survival of 90 which also indicated better survival. DCC high expression showed mean overall survival of 90 which indicated better survival. The correlation between the biomarkers and overall survival were not statistically significant. Conclusion: The results from this study suggest that PD-L1, TYMS and DCC expression could be used as biomarkers to predict treatment outcome in CRC. PD-L1 overexpression predicts patients who could benefit from anti-PD-1 and anti-PD-L1 immunotherapy whilst TYMS low expression predicts patients who could benefit from 5-fluorouracil therapy. DCC high expression tumours predicts a better prognosis and overall survival compared to DCC-negative tumours in advanced CRC.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  5. Pooi, Pooi Leong, Heng, Fong Seow
    MyJurnal
    Cancer immunotherapy is a form of treatment protocol for cancer patients that has been studied intensively over the last two decades. The undesirable side effects during the course of conventional treatment has lead to the development of immunotherapy as an alternative treatment modality. This approach encompasses the use of three different strategies with various immunotherapeutic modalities including (i) cytokines and monoclonal antibodies; (ii) activation of antigen presentation cells (APC) by using antigen-specific peptides or sources of antigens such as tumour lysate; and finally (iii) adoptive transfer of ex vivo activated autologous cytotoxic T-cells. Due to specific-targeting by antigen-specific monoclonal antibodies, dendritic cells and activated CD8+ T-cells, immunotherapy can eliminate tumour
    cells efficiently but the normal tissues are unaffected. Despite years of investigation, the outcome of immunotherapy-based clinical trials are inconsistent with very low response rates from patients. Several mechanisms have been proposed to contribute to this failure including the presence of regulatory T-cells (Treg), immunomodulatory cytokines, and aberrant gene expression in tumour cells. This review summarises information from about 140 articles and review papers. In addition, it also provides an update on recent trends in combinational immunotherapy with conventional therapy and encouraging results have been obtained. Reevaluation of previous studies is necessary to fine-tune the design and approach of immunotherapy to ensure better treatment outcomes.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  6. Yap, Wei Boon, Toong, Seng Tan, Sharifah Syed Hassan, Jeffrey Cheah
    MyJurnal
    Each year, influenza A infections have caused tremendous death rate as high as 300,000-500,000 globally. Although
    there are effective anti-influenza agents and vaccines, high mutational rate among influenza A viruses renders dramatic
    decline in the effectiveness of anti-influenza agents or vaccines in certain individuals. The situation is further complicated
    by limitations in influenza vaccine production, for instance, long production period, limited vaccine capacity and lack
    of cross-protection against various influenza A virus strains. To solve these issues, development of universal influenza
    vaccine based on conserved antigens such as non-stuctural protein 1 (NS1) has been endeavoured. NS1 protein is highly
    conserved in all influenza A virus strains known by far, produced abundantly on infected cell surfaces and responsible for
    maintaining virulence. Furthermore, cytotoxic T-lymphocytes that are active against NS1 were also reported to be able
    to avoid shedding of influenza in hosts. To better inhibit influenza infections, oral immunization has long been proposed
    due to feasibility of this method to be implemented and safer for recipients while able to target influenza A viruses from
    the entry point. Lactobacillus has been vastly studied for its roles as bacterial carrier in oral vaccine development due
    to its significant probiotic properties. For examples, stimulation of immune responses in oral and airway mucosal layers,
    high colonization in oral and airway mucosal layers and great natural adjuvant effects. In this light, influenza universal
    oral vaccine developed using NS1 dan Lactobacillus should be further studied in influenza oral vaccine design.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  7. Subramani B, Pullai CR, Krishnan K, Sugadan SD, Deng X, Hiroshi T, et al.
    Biomed Rep, 2014 Jul;2(4):505-508.
    PMID: 24944796
    Immune cell-based therapies using natural killer (NK) cells and cytotoxic T cells are under constant scrutiny, with the aim to design an effective and reduced-toxicity therapy, which will benefit patients via improved quality of life and improved prognosis. Four patients with stage IV colon cancer were administered 1, 3, 5 and 6 effector cell intravenous infusions, respectively. Peripheral blood was collected from the patients and the ex vivo activation and expansion of NK and T cells was performed in Good Manufacturing Practice-certified clean rooms for ~12-15 days. Immunophenotypic analysis of the peripheral blood mononuclear cells (PBMCs) and expanded NK and T cells was conducted using flow cytometry and the patients were followed up. On average, 4.8×107 initial PBMCs and 2.7×109 total expanded cells were obtained. The intravenous infusions of the expanded cells were not accompanied by adverse reactions. Improved prognosis, reflected by a considerable decrease in the cancer markers, accompanied by an improved quality of life in the patients were observed. In conclusion, potential strategies are currently under development for the large-scale production of effectors cells; therefore, autologous immune enhancement therapy (AIET) may be considered as a viable approach to cancer treatment.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  8. Keynan Y, Card CM, Ball BT, Li Y, Plummer FA, Fowke KR
    Clin Microbiol Infect, 2010 Aug;16(8):1179-86.
    PMID: 20670292 DOI: 10.1111/j.1469-0691.2010.03142.x
    Influenza vaccine provides protection against infection with matched strains, and this protection correlates with serum antibody titres. In addition to antibodies, influenza-specific CD8+ T-lymphocyte responses are important in decreasing disease severity and facilitating viral clearance. Because this response is directed at internal, relatively conserved antigens, it affords some cross-protection within a given subtype of influenza virus. With the possibility of a broader A(H1N1) Mexico outbreak in the fall of 2009, it appeared worthwhile studying the degree of cellular immune response-mediated cross-reactivity among influenza virus isolates. The composition of the 2006-2007 influenza vaccine included the A/New Caledonia/20/1999 strain (comprising a virus that has been circulating, and was included in vaccine preparations, for 6-7 years) and two strains not previously included (Wisconsin and Malaysia). This combination afforded us the opportunity to determine the degree of cross-reactive cellular immunity after exposure to new viral strains. We analysed the antibody responses and the phenotype and function of the T cell response to vaccine components. The results obtained show that antibody responses to A/New-Caledonia were already high and vaccination did not increase antibody or cytotoxic T lymphocyte responses. These data suggest that repeated exposure to the same influenza stain results in limited boosting of humoral and cellular immune responses.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology*
  9. Hafid SR, Radhakrishnan AK, Nesaretnam K
    BMC Cancer, 2010;10:5.
    PMID: 20051142 DOI: 10.1186/1471-2407-10-5
    Dendritic cells (DCs) have the potential for cancer immunotherapy due to their ability to process and present antigens to T-cells and also in stimulating immune responses. However, DC-based vaccines have only exhibited minimal effectiveness against established tumours in mice and humans. The use of appropriate adjuvant enhances the efficacy of DC based cancer vaccines in treating tumours.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology
  10. Hong CY, Wong NK, Abdullah M
    Asian Pac J Allergy Immunol, 2015 Mar;33(1):26-32.
    PMID: 25840631 DOI: 10.12932/AP0463.33.1.2015
    Tamm-Horsfall glycoprotein (THP) and uromodulin are the most abundant glycoproteins in non-pregnant women's/men's and pregnant women's urine, respectively. However, the bioactivities of these glycoproteins are still unclear.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/cytology; T-Lymphocytes, Cytotoxic/drug effects*; T-Lymphocytes, Cytotoxic/immunology; T-Lymphocytes, Cytotoxic/metabolism
  11. Le CF, Kailaivasan TH, Chow SC, Abdullah Z, Ling SK, Fang CM
    Int Immunopharmacol, 2017 Mar;44:203-210.
    PMID: 28119186 DOI: 10.1016/j.intimp.2017.01.013
    Clinacanthus nutans (Burm. f.) Lindau is a traditional medicinal plant belonging to the Acanthaceae family. Its therapeutic potentials have been increasingly documented particularly the antiviral activity against Herpes Simplex Virus (HSV), anti-cancer, anti-oxidant, anti-inflammatory and immunomodulatory activities. However, majority of these studies used crude or fractionated extracts and not much is known about individual compounds from these extracts and their biological activities. In the present study, we have isolated four compounds (CN1, CN2, CN3 and CN4) from the hexane fractions of C. nutans leaves. Using NMR spectroscopic analysis, these compounds were identified to be shaftoside (CN1), stigmasterol (CN2), β-sitosterol (CN3) and a triterpenoid lupeol (CN4). To determine the immunosuppressive potential of these compounds, their effects on mitogens induced T and B lymphocyte proliferation and the secretion of helper T cell cytokines were examined. Among the four compounds, stigmasterol (CN2) and β-sitosterol (CN3) were shown to readily inhibit T cell proliferation mediated by Concanavalin A (ConA). However, only β-sitosterol (CN3) and not stigmasterol (CN2) blocks the secretion of T helper 2 (Th2) cytokines (IL-4 and IL-10). Both compounds have no effect on the secretion of Th1 cytokines (IL-2 and IFN-γ), suggesting that β-sitosterol treatment selectively suppresses Th2 activity and promotes a Th1 bias. CN3 was also found to significantly reduce the proliferation of both T helper cells (CD4(+)CD25(+)) and cytotoxic T cells (CD8(+)CD25(+)) following T cell activation induced by ConA. These results suggested that phytosterols isolated from C. nutans possess immunomodulatory effects with potential development as immunotherapeutics.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/drug effects*; T-Lymphocytes, Cytotoxic/immunology
  12. Chen WT, Wang CW, Lu CW, Chen CB, Lee HE, Hung SI, et al.
    J Invest Dermatol, 2018 07;138(7):1546-1554.
    PMID: 29458119 DOI: 10.1016/j.jid.2018.02.004
    Dapsone-induced hypersensitivity reactions may cause severe cutaneous adverse reactions, such as drug reaction with eosinophilia and systemic symptoms (DRESS). It has been reported that HLA-B*13:01 is strongly associated with dapsone-induced hypersensitivity reactions among leprosy patients. However, the phenotype specificity and detailed immune mechanism of HLA-B*13:01 remain unclear. We investigated the genetic predisposition, HLA-B*13:01 function, and cytotoxic T cells involved in the pathogenesis of dapsone-induced severe cutaneous adverse reactions. We enrolled patients from Taiwan and Malaysia with DRESS and maculopapular eruption with chronic inflammatory dermatoses. Our results showed that the HLA-B*13:01 allele was present in 85.7% (6/7) of patients with dapsone DRESS (odds ratio = 49.64, 95% confidence interval = 5.89-418.13; corrected P = 2.92 × 10-4) but in only 10.8% (73/677) of general population control individuals in Taiwan. The level of granulysin, the severe cutaneous adverse reaction-specific cytotoxic protein released from cytotoxic T cells, was increased in both the plasma of DRESS patients (36.14 ± 9.02 ng/ml, P < 0.05) and in vitro lymphocyte activation test (71.4%, 5/7 patients) compared with healthy control individuals. Furthermore, dapsone-specific cytotoxic T cells were significantly activated when co-cultured with HLA-B*13:01-expressing antigen presenting cells in the presence of dapsone (3.9-fold increase, compared with cells with no HLA-B*13:01 expression; P < 0.01). This study indicates that HLA-B*13:01 is strongly associated with dapsone DRESS and describes a functional role for the HLA-restricted immune mechanism induced by dapsone.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/drug effects; T-Lymphocytes, Cytotoxic/immunology
  13. Zamberi NR, Abu N, Mohamed NE, Nordin N, Keong YS, Beh BK, et al.
    Integr Cancer Ther, 2016 Dec;15(4):NP53-NP66.
    PMID: 27230756
    BACKGROUND: Kefir is a unique cultured product that contains beneficial probiotics. Kefir culture from other parts of the world exhibits numerous beneficial qualities such as anti-inflammatory, immunomodulation, and anticancer effects. Nevertheless, kefir cultures from different parts of the world exert different effects because of variation in culture conditions and media. Breast cancer is the leading cancer in women, and metastasis is the major cause of death associated with breast cancer. The antimetastatic and antiangiogenic effects of kefir water made from kefir grains cultured in Malaysia were studied in 4T1 breast cancer cells.

    METHODS: 4T1 cancer cells were treated with kefir water in vitro to assess its antimigration and anti-invasion effects. BALB/c mice were injected with 4T1 cancer cells and treated orally with kefir water for 28 days.

    RESULTS: Kefir water was cytotoxic toward 4T1 cells at IC50 (half-maximal inhibitory concentration) of 12.5 and 8.33 mg/mL for 48 and 72 hours, respectively. A significant reduction in tumor size and weight (0.9132 ± 0.219 g) and a substantial increase in helper T cells (5-fold) and cytotoxic T cells (7-fold) were observed in the kefir water-treated group. Proinflammatory and proangiogenic markers were significantly reduced in the kefir water-treated group.

    CONCLUSIONS: Kefir water inhibited tumor proliferation in vitro and in vivo mainly through cancer cell apoptosis, immunomodulation by stimulating T helper cells and cytotoxic T cells, and anti-inflammatory, antimetastatic, and antiangiogenesis effects. This study brought out the potential of the probiotic beverage kefir water in cancer treatment.

    Matched MeSH terms: T-Lymphocytes, Cytotoxic/drug effects
  14. Mirsafian H, Manda SS, Mitchell CJ, Sreenivasamurthy S, Ripen AM, Mohamad SB, et al.
    Genomics, 2016 07;108(1):37-45.
    PMID: 26778813 DOI: 10.1016/j.ygeno.2016.01.002
    Long non-coding RNAs (lncRNAs) have been shown to possess a wide range of functions in both cellular and developmental processes including cancers. Although some of the lncRNAs have been implicated in the regulation of the immune response, the exact function of the large majority of lncRNAs still remains unknown. In this study, we characterized the lncRNAs in human primary monocytes, an essential component of the innate immune system. We performed RNA sequencing of monocytes from four individuals and combined our data with eleven other publicly available datasets. Our analysis led to identification of ~8000 lncRNAs of which >1000 have not been previously reported in monocytes. PCR-based validation of a subset of the identified novel long intergenic noncoding RNAs (lincRNAs) revealed distinct expression patterns. Our study provides a landscape of lncRNAs in monocytes, which could facilitate future experimental studies to characterize the functions of these molecules in the innate immune system.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/metabolism
  15. Chai SJ, Fong SCY, Gan CP, Pua KC, Lim PVH, Lau SH, et al.
    Hum Vaccin Immunother, 2019;15(1):167-178.
    PMID: 30193086 DOI: 10.1080/21645515.2018.1520584
    Peptide vaccines derived from tumour-associated antigens have been used as an immunotherapeutic approach to induce specific cytotoxic immune response against tumour. We previously identified that MAGED4B and FJX1 proteins are overexpressed in HNSCC patients; and further demonstrated that two HLA-A2-restricted 9-11 amino acid peptides derived from these proteins were able to induce anti-tumour immune responses in vitro independently using PBMCs isolated from these patients. In this study, we evaluated the immunogenicity and efficacy of a dual-antigenic peptide vaccine (PV1), comprised of MAGED4B and FJX1 peptides in HNSCC patients. We first demonstrated that 94.8% of HNSCC patients expressed MAGED4B and/or FJX1 by immunohistochemistry, suggesting that PV1 could benefit the majority of HNSCC patients. The presence of pre-existing MAGED4B and FJX1-specific T-cells was detected using a HLA-A2 dimer assay and efficacy of PV1 to induce T-cell to secrete cytotoxic cytokine was evaluated using ELISPOT assay. Pre-existing PV1-specific T-cells were detected in all patients. Notably, we demonstrated that patients' T-cells were able to secrete cytotoxic cytokines upon exposure to target cells expressing the respective antigen post PV1 stimulation. Furthermore, patients with high expression of MAGED4B and FJX1 in their tumours were more responsive to PV1 stimulation, demonstrating the specificity of the PV1 peptide vaccine. Additionally, we also demonstrated the expression of MAGED4B and FJX1 in breast, lung, colon, prostate and rectal cancer suggesting the potential use of PV1 in these cancers. In summary, PV1 could be a good vaccine candidate for the treatment of HNSCC patients and other cancers expressing these antigens.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology*
  16. AL-Battawi, S., Hameed, S., Ng, E.S.C., Amini, F.
    JUMMEC, 2018;21(2):45-52.
    MyJurnal
    Graft-versus-host Disease (GVHD) is the main cause of morbidity and mortality after allogeneic hematopoietic
    stem cell transplantation (alloHSCT). In spite of immune-suppressive prophylaxis, most survivors suffer from
    acute and chronic GVHD (aGVHD and cGVHD). The outcome of alloHSCT may be affected by the presence of
    single nucleotide polymorphism (SNP) in non-HLA genes including those involved in innate immune responses.
    This study aimed to evaluate the impact of cytotoxic T-lymphocyte antigen-4 (CTLA-4) and caspase recruitment
    domain 15 (NOD2/CARD15) gene polymorphisms on the incidence and severity of aGVHD and cGVHD following
    alloHSCT. A structured literature review was carried out using various keywords and MESH terms such as
    stem cell transplantation, allogenic haematopoietic stem cell transplantation, GVHD, and non-HLA gene
    polymorphism, in PubMed, Google Scholar and Cochrane Database. A total of 8 studies that met inclusion
    criteria (English publications from 2006 to 2017) were included. Ten SNPs in CTLA-4 gene and three SNPs in
    NOD2/CARD15 gene were tested in patients with underlying haematological malignancies. Four studies tested
    the SNPs of CTLA-4 gene and two were found to have an association with CTLA-4 SNPs (rs3087243, rs231775)
    and increased incidence of aGVHD. The other four studies tested the SNPs of NOD2/CARD15 gene and one
    found an association between SNP13 and increased incidence of aGVHD. None of these eight studies found
    any effect on severity of GVHD. In conclusion, two SNPs in CTLA-4 and one SNP in NOD2/CARD15 increased
    the incidence of aGVHD but not its severity. The higher incidence of aGVHD in studies with larger sample size
    could support the impact of SNPs in the outcome of alloHSCT. However, due to the heterogeneity of studies in
    regard to the age of patients and donor, and conditioning regimen, it is difficult to draw a definite conclusion.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  17. Ninyio NN, Ho KL, Ong HK, Yong CY, Chee HY, Hamid M, et al.
    Vaccines (Basel), 2020 Jun 04;8(2).
    PMID: 32512923 DOI: 10.3390/vaccines8020275
    Chimeric virus-like particles (VLPs) have been widely exploited for various purposes including their use as vaccine candidates, particularly due to their ability to induce stronger immune responses than VLPs consisting of single viral proteins. In the present study, VLPs of the Macrobrachium rosenbergii nodavirus (MrNV) capsid protein (Nc) displaying the hepatitis B virus "a" determinant (aD) were produced in Spodoptera frugiperda (Sf9) insect cells. BALB/c mice immunised with the purified chimeric Nc-aD VLPs elicited a sustained titre of anti-aD antibody, which was significantly higher than that elicited by a commercially available hepatitis B vaccine and Escherichia coli-produced Nc-aD VLPs. Immunophenotyping showed that the Sf9-produced Nc-aD VLPs induced proliferation of cytotoxic T-lymphocytes and NK1.1 natural killer cells. Furthermore, enzyme-linked immunospot (ELISPOT)analysis showed the presence of antibody-secreting memory B cells in the mice splenocytes stimulated with the synthetic aD peptide. The significant humoral, natural killer cell and memory B cell immune responses induced by the Sf9-produced Nc-aD VLPs suggest that they present good prospects for use as a hepatitis B vaccine candidate.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  18. Mohamud R, LeMasurier JS, Boer JC, Sieow JL, Rolland JM, O'Hehir RE, et al.
    Front Immunol, 2017;8:1812.
    PMID: 29312323 DOI: 10.3389/fimmu.2017.01812
    Synthetic glycine coated 50 nm polystyrene nanoparticles (NP) (PS50G), unlike ambient NP, do not promote pulmonary inflammation, but instead, render lungs resistant to the development of allergic airway inflammation. In this study, we show that PS50G modulate the frequency and phenotype of regulatory T cells (Treg) in the lung, specifically increasing the proportion of tumor necrosis factor 2 (TNFR2) expressing Treg. Mice pre-exposed to PS50G, which were sensitized and then challenged with an allergen a month later, preferentially expanded TNFR2+Foxp3+ Treg, which further expressed enhanced levels of latency associated peptide and cytotoxic T-lymphocyte associated molecule-4. Moreover, PS50G-induced CD103+ dendritic cell activation in the lung was associated with the proliferative expansion of TNFR2+Foxp3+ Treg. These findings provide the first evidence that engineered NP can promote the selective expansion of maximally suppressing TNFR2+Foxp3+ Treg and further suggest a novel mechanism by which NP may promote healthy lung homeostasis.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic
  19. Lim KP, Chun NA, Gan CP, Teo SH, Rahman ZA, Abraham MT, et al.
    Hum Vaccin Immunother, 2014;10(11):3214-23.
    PMID: 25483651 DOI: 10.4161/hv.29226
    The ever-increasing number of tumor-associated antigens has provided a major stimulus for the development of therapeutic peptides vaccines. Tumor-associated peptides can induce high immune response rates and have been developed as vaccines for several types of solid tumors, and many are at various stages of clinical testing. MAGED4B, a melanoma antigen, is overexpressed in oral squamous cell carcinoma (OSCC) and this expression promotes proliferation and cell migration. In this study, we have identified 9 short peptides derived from MAGED4B protein that are restricted in binding to the HLA subtypes common in the Asian population (HLA-A2, A11, and A24). The peptides had good binding affinity with the MHC-Class I molecules and stimulated ex-vivo IFN-gamma and Granzyme-B production in blood samples from OSCC patients, suggesting that they are immunogenic. Further, T cells stimulated with peptide-pulsed dendritic cells showed enhanced T-cell cytotoxic activity against MAGED4B-overexpressing OSCC cell lines. In summary, we have identified MAGED4B peptides that induce anti-tumor immune responses advocating that they could be further developed as vaccine candidates for the treatment of OSCC.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology*
  20. Yap LF, Velapasamy S, Lee HM, Thavaraj S, Rajadurai P, Wei W, et al.
    J Pathol, 2015 Feb;235(3):456-65.
    PMID: 25294670 DOI: 10.1002/path.4460
    Undifferentiated nasopharyngeal carcinoma (NPC) is a highly metastatic disease that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the contribution of lysophosphatidic acid (LPA) signalling to the pathogenesis of NPC. Here we demonstrate two distinct functional roles for LPA in NPC. First, we show that LPA enhances the migration of NPC cells and second, that it can inhibit the activity of EBV-specific cytotoxic T cells. Focusing on the first of these phenotypes, we show that one of the LPA receptors, LPA receptor 5 (LPAR5), is down-regulated in primary NPC tissues and that this down-regulation promotes the LPA-induced migration of NPC cell lines. Furthermore, we found that EBV infection or ectopic expression of the EBV-encoded LMP2A was sufficient to down-regulate LPAR5 in NPC cell lines. Our data point to a central role for EBV in mediating the oncogenic effects of LPA in NPC and identify LPA signalling as a potential therapeutic target in this disease.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/pathology
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