Displaying publications 1 - 20 of 247 in total

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  1. Wong RS, Radhakrishnan AK, Ibrahim TA, Cheong SK
    Microsc Microanal, 2012 Jun;18(3):462-9.
    PMID: 22640960 DOI: 10.1017/S1431927612000177
    Tocotrienols are isomers of the vitamin E family, which have been reported to exert cytotoxic effects in various cancer cells. Although there have been some reports on the effects of tocotrienols in leukemic cells, ultrastructural evidence of tocotrienol-induced apoptotic cell death in leukemic cells is lacking. The present study investigated the effects of three isomers of tocotrienols (alpha, delta, and gamma) on a human T lymphoblastic leukemic cell line (CEM-SS). Cell viability assays showed that all three isomers had cytotoxic effects (p < 0.05) on CEM-SS cells with delta-tocotrienol being the most potent. Transmission electron microscopy showed that the cytotoxic effects by delta- and gamma-tocotrienols were through the induction of an apoptotic pathway as demonstrated by the classical ultrastructural apoptotic changes characterized by peripheral nuclear chromatin condensation and nuclear fragmentation. These findings were confirmed biochemically by the demonstration of phosphatidylserine externalization via flow cytometry analysis. This is the first study showing classical ultrastructural apoptotic changes induced by delta- and gamma-tocotrienols in human T lymphoblastic leukemic cells.
    Matched MeSH terms: T-Lymphocytes/drug effects*; T-Lymphocytes/physiology; T-Lymphocytes/ultrastructure
  2. Cowan AJ, Pont MJ, Sather BD, Turtle CJ, Till BG, Libby EN, et al.
    Lancet Oncol, 2023 Jul;24(7):811-822.
    PMID: 37414012 DOI: 10.1016/S1470-2045(23)00246-2
    BACKGROUND: γ-Secretase inhibitors (GSIs) increase B cell maturation antigen (BCMA) density on malignant plasma cells and enhance antitumour activity of BCMA chimeric antigen receptor (CAR) T cells in preclinical models. We aimed to evaluate the safety and identify the recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat (LY3039478) for individuals with relapsed or refractory multiple myeloma.

    METHODS: We conducted a phase 1, first-in-human trial combining crenigacestat with BCMA CAR T-cells at a single cancer centre in Seattle, WA, USA. We included individuals aged 21 years or older with relapsed or refractory multiple myeloma, previous autologous stem-cell transplant or persistent disease after more than four cycles of induction therapy, and Eastern Cooperative Oncology Group performance status of 0-2, regardless of previous BCMA-targeted therapy. To assess the effect of the GSI on BCMA surface density on bone marrow plasma cells, participants received GSI during a pretreatment run-in, consisting of three doses administered 48 h apart. BCMA CAR T cells were infused at doses of 50 × 106 CAR T cells, 150 × 106 CAR T cells, 300 × 106 CAR T cells, and 450 × 106 CAR T cells (total cell dose), in combination with the 25 mg crenigacestat dosed three times a week for up to nine doses. The primary endpoints were the safety and recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat, an oral GSI. This study is registered with ClinicalTrials.gov, NCT03502577, and has met accrual goals.

    FINDINGS: 19 participants were enrolled between June 1, 2018, and March 1, 2021, and one participant did not proceed with BCMA CAR T-cell infusion. 18 participants (eight [44%] men and ten [56%] women) with multiple myeloma received treatment between July 11, 2018, and April 14, 2021, with a median follow up of 36 months (95% CI 26 to not reached). The most common non-haematological adverse events of grade 3 or higher were hypophosphataemia in 14 (78%) participants, fatigue in 11 (61%), hypocalcaemia in nine (50%), and hypertension in seven (39%). Two deaths reported outside of the 28-day adverse event collection window were related to treatment. Participants were treated at doses up to 450 × 106 CAR+ cells, and the recommended phase 2 dose was not reached.

    INTERPRETATIONS: Combining a GSI with BCMA CAR T cells appears to be well tolerated, and crenigacestat increases target antigen density. Deep responses were observed among heavily pretreated participants with multiple myeloma who had previously received BCMA-targeted therapy and those who were naive to previous BCMA-targeted therapy. Further study of GSIs given with BCMA-targeted therapeutics is warranted in clinical trials.

    FUNDING: Juno Therapeutics-a Bristol Myers Squibb company and the National Institutes of Health.

    Matched MeSH terms: T-Lymphocytes
  3. Jantan I, Haque MA, Ilangkovan M, Arshad L
    Int Immunopharmacol, 2019 Aug;73:552-559.
    PMID: 31177081 DOI: 10.1016/j.intimp.2019.05.035
    Zerumbone exhibited various biological properties including in vitro immunosuppressive effects. However, its modulatory activity on the immune responses in experimental animal model is largely unknown. This investigation was conducted to explore the effects of daily treatment of zerumbone (25, 50, and 100 mg/kg) isolated from Zingiber zerumbet rhizomes for 14 days on various cellular and humoral immune responses in Balb/C mice. For measurement of adaptive immunity, sheep red blood cells (sRBC) were used to immunize the mice on day 0 and orally fed with similar doses of zerumbone for 14 days. The effects of zerumbone on phagocytosis, nitric oxide (NO) release, myeloperoxidase (MPO) activity, proliferation of T and B cells, lymphocyte phenotyping, cytokines release in serum by activated T cells, delayed type hypersensitivity (DTH) and immunoglobulins production (IgG and IgM) were investigated. Zerumbone downregulated the engulfment of E. coli by peritoneal macrophages and the release of NO and MPO in a concentration-dependent manner. Zerumbone showed significant and concentration-dependent suppression of T and B lymphocytes proliferation and inhibition of the Th1 and Th2 cytokines release. At higher concentrations of zerumbone, the % expression of CD4+ and CD8+ in splenocytes was significantly inhibited. Zerumbone also concentration-dependently demonstrated strong suppression on sRBC-triggered swelling of mice paw in DTH. Substantial suppression of anti-sRBC immunoglobulins antibody titer was noted in immunized and zerumbone-treated mice in a concentration-dependent manner. The potent suppressive effects of zerumbone on the immune responses suggest that zerumbone can be a potential candidate for development of immunosuppressive agent.
    Matched MeSH terms: T-Lymphocytes/drug effects
  4. Soh JE, Abu N, Sagap I, Mazlan L, Yahaya A, Mustangin M, et al.
    Immunotherapy, 2019 10;11(14):1205-1219.
    PMID: 31478431 DOI: 10.2217/imt-2019-0073
    Colorectal cancer is the third commonest malignancy in Asia including Malaysia. The immunogenic cancer-testis antigens, which are expressed in a variety of cancers but with limited expression in normal tissues except the testis, represent an attractive approach to improve treatment options for colorectal cancer. We aimed to validate four PASD1 peptides as the immunotherapeutic targets in colorectal cancer. First, PASD1 mRNA and protein expression were determined via real-time polymerase chain reaction (RT-PCR) and immunohistochemistry. The PASD1 peptides specific to HLA-A*24:02 were investigated using IFN-y-ELISpot assay, followed by the cytolytic and granzyme-B-ELISpot assays to analyze the cytolytic effects of CD8+ T cells. Gene and protein expressions of PASD1 were detected in 20% and 17.3% of colorectal cancer samples, respectively. PASD1(4) peptide was shown to be immunogenic in colorectal cancer samples. CD8+ T cells raised against PASD1(4) peptide were able to lyze HLA-A*24:02+ PASD1+ cells. Our results reveal that PASD1(4) peptide represents a potential target for colorectal cancer.
    Matched MeSH terms: CD8-Positive T-Lymphocytes/immunology; CD8-Positive T-Lymphocytes/pathology
  5. Puvanesuaran VR, Nowroji K, Sreenivasan S, Noordin R, Balakrishnan V
    Eur Rev Med Pharmacol Sci, 2012 Aug;16(8):1028-32.
    PMID: 22913152
    AIM: To determine the usefulness of prednisolone in increasing the number of Toxoplasma (T.) gondii tachyzoites and bradyzoites in mice.
    MATERIALS AND METHODS: The mice were water-fasted prior to being immunosuppressed with oral inoculation of prednisolone. Tachyzoites of 7T gondii RH strain were inoculated into mice and the number of the parasites in the intraperitoneal fluids was then determined at 96 hs post-infection. In addition, tachyzoites of T. gondii ME49 strains were orally introduced into mice and the number of brain cysts formed was observed by microscopic observation at 45 days post-infection.
    RESULTS: T. gondii propagation was found to be significantly improved by introduction of the prednisolone (p = 0.0004); and the number of parasite showed positive correlation with the increment in dosage of prednisolone (r = 0.9051).
    CONCLUSIONS: The use of prednisolone greatly improved the number of parasite formed in mice: both tachyzoite and cyst forms.
    Matched MeSH terms: CD4-Positive T-Lymphocytes/drug effects; CD8-Positive T-Lymphocytes/drug effects
  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. Kue CS, Kamkaew A, Voon SH, Kiew LV, Chung LY, Burgess K, et al.
    Sci Rep, 2016 11 17;6:37209.
    PMID: 27853305 DOI: 10.1038/srep37209
    Tropomyosin receptor kinase C (TrkC) targeted ligand-photosensitizer construct, IYIY-diiodo-boron-dipyrromethene (IYIY-I2-BODIPY) and its scrambled counterpart YIYI-I2-BODIPY have been prepared. IYIY-I2-BODIPY binds TrkC similar to neurotrophin-3 (NT-3), and NT-3 has been reported to modulate immune responses. Moreover, it could be shown that photodynamic therapy (PDT) elevates antitumor immune responses. This prompted us to investigate the immunological impacts mediated by IYIY-I2-BODIPY in pre- and post-PDT conditions. We demonstrated that IYIY-I2-BODIPY (strong response) and YIYI-I2-BODIPY (weak response) at 10 mg/kg, but not I2-BODIPY control, increased the levels of IL-2, IL-4, IL-6 and IL-17, but decreased the levels of systemic immunoregulatory mediators TGF-β, myeloid-derived suppressor cells and regulatory T-cells. Only IYIY-I2-BODIPY enhanced the IFN-γ+ and IL-17+ T-lymphocytes, and delayed tumor growth (~20% smaller size) in mice when administrated daily for 5 days. All those effects were observed without irradiation; when irradiated (520 nm, 100 J/cm2, 160 mW/cm2) to produce PDT effects (drug-light interval 1 h), IYIY-I2-BODIPY induced stronger responses. Moreover, photoirradiated IYIY-I2-BODIPY treated mice had high levels of effector T-cells compared to controls. Adoptive transfer of immune cells from IYIY-I2-BODIPY-treated survivor mice that were photoirradiated gave significantly delayed tumor growth (~40-50% smaller size) in recipient mice. IYIY-I2-BODIPY alone and in combination with PDT modulates the immune response in such a way that tumor growth is suppressed. Unlike immunosuppressive conventional chemotherapy, IYIY-I2-BODIPY can act as an immune-stimulatory chemotherapeutic agent with potential applications in clinical cancer treatment.
    Matched MeSH terms: T-Lymphocytes, Regulatory/immunology*; T-Lymphocytes, Regulatory/pathology
  8. Jiamsakul A, Azwa I, Zhang F, Yunihastuti E, Ditangco R, Kumarasamy N, et al.
    Antivir Ther, 2020;25(7):377-387.
    PMID: 33616550 DOI: 10.3851/IMP3384
    BACKGROUND: The World Health Organization recommends continuation with the failing second-line regimen if third-line option is not available. We investigated treatment outcomes among people living with HIV in Asia who continued with failing second-line regimens compared with those who had treatment modifications after failure.

    METHODS: Treatment modification was defined as a change of two antiretrovirals, a drug class change or treatment interruption (TI), all for >14 days. We assessed factors associated with CD4 changes and undetectable viral load (UVL <1,000 copies/ml) at 1 year after second-line failure using linear and logistic regression, respectively. Survival time was analysed using competing risk regression.

    RESULTS: Of the 328 patients who failed second-line ART in our cohorts, 208 (63%) had a subsequent treatment modification. Compared with those who continued the failing regimen, the average CD4 cell increase was higher in patients who had a modification without TI (difference =77.5, 95% CI 35.3, 119.7) while no difference was observed among those with TI (difference =-5.3, 95% CI -67.3, 56.8). Compared with those who continued the failing regimen, the odds of achieving UVL was lower in patients with TI (OR=0.18, 95% CI 0.06, 0.60) and similar among those who had a modification without TI (OR=1.97, 95% CI 0.95, 4.10), with proportions of UVL 60%, 22% and 75%, respectively. Survival time was not affected by treatment modifications.

    CONCLUSIONS: CD4 cell improvements were observed in those who had treatment modification without TI compared with those on the failing regimen. When no other options are available, maintaining the same failing ART combination provided better VL control than interrupting treatment.

    Matched MeSH terms: CD4-Positive T-Lymphocytes
  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. Abdul Hafid SR, Chakravarthi S, Nesaretnam K, Radhakrishnan AK
    PLoS One, 2013;8(9):e74753.
    PMID: 24069344 DOI: 10.1371/journal.pone.0074753
    Tocotrienol-rich fraction (TRF) from palm oil is reported to possess anti-cancer and immune-enhancing effects. In this study, TRF supplementation was used as an adjuvant to enhance the anti-cancer effects of dendritic cells (DC)-based cancer vaccine in a syngeneic mouse model of breast cancer. Female BALB/c mice were inoculated with 4T1 cells in mammary pad to induce tumor. When the tumor was palpable, the mice in the experimental groups were injected subcutaneously with DC-pulsed with tumor lysate (TL) from 4T1 cells (DC+TL) once a week for three weeks and fed daily with 1 mg TRF or vehicle. Control mice received unpulsed DC and were fed with vehicle. The combined therapy of using DC+TL injections and TRF supplementation (DC+TL+TRF) inhibited (p<0.05) tumor growth and metastasis. Splenocytes from the DC+TL+TRF group cultured with mitomycin-C (MMC)-treated 4T1 cells produced higher (p<0.05) levels of IFN-γ and IL-12. The cytotoxic T-lymphocyte (CTL) assay also showed enhanced tumor-specific killing (p<0.05) by CD8(+) T-lymphocytes isolated from mice in the DC+TL+TRF group. This study shows that TRF has the potential to be used as an adjuvant to enhance effectiveness of DC-based vaccines.
    Matched MeSH terms: T-Lymphocytes, Cytotoxic/immunology; T-Lymphocytes, Cytotoxic/metabolism
  11. Looi CK, Chung FF, Leong CO, Wong SF, Rosli R, Mai CW
    J Exp Clin Cancer Res, 2019 Apr 15;38(1):162.
    PMID: 30987642 DOI: 10.1186/s13046-019-1153-8
    BACKGROUND: Pancreatic cancer is one of the most lethal type of cancers, with an overall five-year survival rate of less than 5%. It is usually diagnosed at an advanced stage with limited therapeutic options. To date, no effective treatment options have demonstrated long-term benefits in advanced pancreatic cancer patients. Compared with other cancers, pancreatic cancer exhibits remarkable resistance to conventional therapy and possesses a highly immunosuppressive tumor microenvironment (TME).

    MAIN BODY: In this review, we summarized the evidence and unique properties of TME in pancreatic cancer that may contribute to its resistance towards immunotherapies as well as strategies to overcome those barriers. We reviewed the current strategies and future perspectives of combination therapies that (1) promote T cell priming through tumor associated antigen presentation; (2) inhibit tumor immunosuppressive environment; and (3) break-down the desmoplastic barrier which improves tumor infiltrating lymphocytes entry into the TME.

    CONCLUSIONS: It is imperative for clinicians and scientists to understand tumor immunology, identify novel biomarkers, and optimize the position of immunotherapy in therapeutic sequence, in order to improve pancreatic cancer clinical trial outcomes. Our collaborative efforts in targeting pancreatic TME will be the mainstay of achieving better clinical prognosis among pancreatic cancer patients. Ultimately, pancreatic cancer will be a treatable medical condition instead of a death sentence for a patient.

    Matched MeSH terms: T-Lymphocytes/drug effects; T-Lymphocytes/immunology; T-Lymphocytes/metabolism
  12. Ahmad S, Hatmal MM, Lambuk L, Al-Hatamleh MAI, Alshaer W, Mohamud R
    Life Sci, 2021 Dec 01;286:120063.
    PMID: 34673116 DOI: 10.1016/j.lfs.2021.120063
    COVID-19 is a multi-faceted disease ranging from asymptomatic to severely ill condition that primarily affects the lungs and could advance to other organs as well. It's causing factor, SARS-CoV-2 is recognized to develop robust cell-mediated immunity that responsible to either control or exaggerate the infection. As an important cell subset that control immune responses and are significantly dysregulated in COVID-19, Tregs is proposed to be considered for COVID-19 management. Among its hallmark, TNFR2 is recently recognized to play important role in the function and survival of Tregs. This review gathers available TNFR2 agonists to directly target Tregs as a potential approach to overcome immune dysregulation that affect the severity in COVID-19. Furthermore, this review performs a rigid body docking of TNF-TNFR2 interaction and such interaction with TNFR2 agonist to predict the optimal targeting approach.
    Matched MeSH terms: T-Lymphocytes, Regulatory/immunology*
  13. Sosroseno W, Bird PS, Gemmell E, Seymour GJ
    J. Periodontol., 2002 Oct;73(10):1133-40.
    PMID: 12416770
    It has previously been suggested that CD4+ T cells play a pivotal role in regulating the immune response to periodontal pathogens. The aim of the present study therefore was to determine delayed type hypersensitivity (DTH), spleen cell proliferation, serum and splenic anti-Porphyromonas gingivalis antibody levels, and lesion sizes following challenge with viable P. gingivalis in CD4-depleted BALB/c mice immunized with P. gingivalis outer membrane proteins (OMP).
    Matched MeSH terms: CD4-Positive T-Lymphocytes/physiology*
  14. Sosroseno W, Bird PS, Gemmell E, Seymour GJ
    Oral Microbiol. Immunol., 2006 Dec;21(6):411-4.
    PMID: 17064401
    The aim of this study was to determine the role of CD4 and CD8 cells on specific antibody production by murine Peyer's patch (PP) cells after oral immunization with Actinomyces viscosus in mice. Female DBA/2 mice were orally immunized with three low doses of heat-killed A. viscosus. Sham-immunized mice served as a control group. Mice were depleted of CD4 or CD8 cells by intraperitoneal injection of anti-CD4 or anti-CD8 antibodies daily for 3 days before oral immunization. One week after the last oral immunization, PPs were removed and cell suspensions were cultured with A. viscosus. Specific antibody production in the culture supernatants was assessed by enzyme-linked immunosorbent assay. The results showed that oral immunization with A. viscosus induced a predominant specific immunoglobulin A (IgA) response by PP cells and, to a lesser extent, IgM antibodies. Depletion of CD4 but not CD8 cells suppressed the production of specific antibodies. These results suggest that oral immunization with low doses of A. viscosus may induce the production of specific antibodies by murine PP cells in a CD4-cell-dependent fashion.
    Matched MeSH terms: CD4-Positive T-Lymphocytes/physiology*; CD8-Positive T-Lymphocytes/physiology*
  15. Norazmi MN, Mohamed R, Nurul AA, Yaacob NS
    Clin. Dev. Immunol., 2012;2012:849195.
    PMID: 22548115 DOI: 10.1155/2012/849195
    Given their roles in immune regulation, the expression of the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) 1 and 2 isoforms was investigated in human naïve (CD45RA+) and memory (CD45RO+) CD4+ T cells. Stimulation of both types of cells via the CD3/CD28 pathway resulted in high expression of both PPARγ receptors as measured by real-time PCR. Treatment with the PPARγ agonist, ciglitazone, increased PPARγ1 expression but decreased PPARγ2 expression in stimulated naïve and memory cells. Furthermore, when present, the magnitude of both PPARγ receptors expression was lower in naïve cells, perhaps suggesting a lower regulatory control of these cells. Similar profiles of selected proinflammatory cytokines were expressed by the two cell types following stimulation. The induction of PPARγ1 and suppression of PPARγ2 expressions in naïve and memory CD4+ T cells in the presence of ciglitazone suggest that the PPARγ subtypes may have different roles in the regulation of T-cell function.
    Matched MeSH terms: CD4-Positive T-Lymphocytes/cytology; CD4-Positive T-Lymphocytes/drug effects*; CD4-Positive T-Lymphocytes/immunology
  16. Ramasamy R, Tong CK, Seow HF, Vidyadaran S, Dazzi F
    Cell Immunol, 2008 Feb;251(2):131-6.
    PMID: 18502411 DOI: 10.1016/j.cellimm.2008.04.009
    Mesenchymal stem cells (MSC) are non-haematopoietic stem cells that are capable of differentiating into tissues of mesodermal origin. MSC play an important role in supporting the development of fetal and adult haematopoiesis. More recently, MSC have also been found to exhibit inhibitory effect on T cell responses. However, there is little information on the mechanism of this immunosuppression and our study addresses this issue by targeting T cell functions at various level of immune responses. We have generated MSC from human adult bone marrow (BM) and investigated their immunoregulatory function at different phases of T cell responses. MSC showed the ability to inhibit mitogen (CD3/CD28 microbeads)-activated T cell proliferation in a dose-dependent manner. In order to evaluate the specificity of this immunosuppression, the proliferation of CD4(+) and CD8(+) cells were measured. MSC equally inhibit CD4(+) and CD8(+) subpopulations of T cells in response to PHA stimulation. However, the antiproliferative effect of MSC is not due to the inhibition of T cell activation. The expression of early activation markers of T cells, namely CD25 and CD69 were not significantly altered by MSC at 24, 48 and 72h. Furthermore, the immunosuppressive effect of MSC mainly targets T cell proliferation rather than their effector function since cytotoxicity of T cells is not affected. This work demonstrates that the immunosuppressive effect of MSC is exclusively a consequence of an anti-proliferative activity, which targets T cells of different subpopulations. For this reason, they have the potential to be exploited in the control of unwanted immune responses such as graft versus host disease (GVHD) and autoimmunity.
    Matched MeSH terms: CD4-Positive T-Lymphocytes/cytology; CD4-Positive T-Lymphocytes/immunology*; CD8-Positive T-Lymphocytes/cytology; CD8-Positive T-Lymphocytes/immunology*
  17. Khan KM, Mesaik MA, Abdalla OM, Rahim F, Soomro S, Halim SA, et al.
    Bioorg Chem, 2016 Feb;64:21-8.
    PMID: 26637945 DOI: 10.1016/j.bioorg.2015.11.004
    Benzothiazole and its natural or synthetic derivatives have been used as precursors for several pharmacological agents for neuroprotective, anti-bacterial, and anti-allergic activities. The objective of the present study was to evaluate effects of benzothiazole analogs (compounds 1-26) for their immunomodulatory activities. Eight compounds (2, 4, 5, 8-10, 12, and 18) showed potent inhibitory activity on PHA-activated peripheral blood mononuclear cells (PBMCs) with IC50 ranging from 3.7 to 11.9 μM compared to that of the standard drug, prednisolone <1.5 μM. Some compounds (2, 4, 8, and 18) were also found to have potent inhibitory activities on the production of IL-2 on PHA/PMA-stimulated PBMCs with IC50 values ranging between <4.0 and 12.8 μM. The binding interaction of these compounds was performed through silico molecular docking. Compounds 2, 8, 9, and 10 significantly suppressed oxidative burst ROS production in phagocytes with IC50 values between <4.0 and 15.2 μM. The lipopolysaccharide (LPS)-induced nitrites in murine macrophages cell line J774 were found to be inhibited by compounds 4, 8, 9, and 18 at a concentration of 25 μg/mL by 56%, 91%, 58%, and 78%, respectively. Furthermore, compounds 5, 8, 12, and 18 showed significant (P<0.05) suppressive activity on Th-2 cytokine, interleukin 4 (IL-4) with an IC50 range of <4.0 to 40.3 μM. Interestingly compound 4 has shown a selective inhibitory activity on IL-2 and T cell proliferation (naïve T cell proliferation stage) rather than on IL-4 cytokine, while compound 12 displayed an interference with T-cell proliferation and IL-4 generation. Moreover compound 8 and 18 exert non-selective inhibition on both IL-2 and IL-4 cytokines, indicating a better interference with stage leading to humoral immune response and hence possible application in autoimmune diseases.
    Matched MeSH terms: T-Lymphocytes/drug effects; T-Lymphocytes/metabolism
  18. Engelhardt KR, Gertz ME, Keles S, Schäffer AA, Sigmund EC, Glocker C, et al.
    J Allergy Clin Immunol, 2015 Aug;136(2):402-12.
    PMID: 25724123 DOI: 10.1016/j.jaci.2014.12.1945
    BACKGROUND: Mutations in dedicator of cytokinesis 8 (DOCK8) cause a combined immunodeficiency (CID) also classified as autosomal recessive (AR) hyper-IgE syndrome (HIES). Recognizing patients with CID/HIES is of clinical importance because of the difference in prognosis and management.

    OBJECTIVES: We sought to define the clinical features that distinguish DOCK8 deficiency from other forms of HIES and CIDs, study the mutational spectrum of DOCK8 deficiency, and report on the frequency of specific clinical findings.

    METHODS: Eighty-two patients from 60 families with CID and the phenotype of AR-HIES with (64 patients) and without (18 patients) DOCK8 mutations were studied. Support vector machines were used to compare clinical data from 35 patients with DOCK8 deficiency with those from 10 patients with AR-HIES without a DOCK8 mutation and 64 patients with signal transducer and activator of transcription 3 (STAT3) mutations.

    RESULTS: DOCK8-deficient patients had median IgE levels of 5201 IU, high eosinophil levels of usually at least 800/μL (92% of patients), and low IgM levels (62%). About 20% of patients were lymphopenic, mainly because of low CD4(+) and CD8(+) T-cell counts. Fewer than half of the patients tested produced normal specific antibody responses to recall antigens. Bacterial (84%), viral (78%), and fungal (70%) infections were frequently observed. Skin abscesses (60%) and allergies (73%) were common clinical problems. In contrast to STAT3 deficiency, there were few pneumatoceles, bone fractures, and teething problems. Mortality was high (34%). A combination of 5 clinical features was helpful in distinguishing patients with DOCK8 mutations from those with STAT3 mutations.

    CONCLUSIONS: DOCK8 deficiency is likely in patients with severe viral infections, allergies, and/or low IgM levels who have a diagnosis of HIES plus hypereosinophilia and upper respiratory tract infections in the absence of parenchymal lung abnormalities, retained primary teeth, and minimal trauma fractures.

    Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology; CD4-Positive T-Lymphocytes/pathology; CD8-Positive T-Lymphocytes/immunology; CD8-Positive T-Lymphocytes/pathology
  19. Yaacob NS, Kaderi MA, Norazmi MN
    J Clin Immunol, 2004 Mar;24(2):177-84.
    PMID: 15024185 DOI: 10.1023/B:JOCI.0000019783.61674.1d
    Type 1 diabetes is an autoimmune disease that results from the destruction of the insulin-producing pancreatic beta islet cells, probably via the influence of cytokines. However, direct correlation between the expression of selected cytokines by various immune cells at different time points during the progression of the disease has not yet been clearly demonstrated. In this study, we showed that the mRNA expression of the pro-inflammatory cytokines, TNF-alpha, IL-1 beta, IL-6, and GM-CSF, were increased while the anti-inflammatory cytokine, TGF-beta, decreased in the peritoneal macrophages of nonobese diabetic (NOD) mice. IL-6 expression however decreased when the mice became diabetic. Surprisingly the expression of IFN-gamma and IL-2 by splenic CD4+ cells were lower in 5-week-old NOD mice as compared to the nonobese diabetic resistant (NOR) control mice, but their expression was higher in older NOD mice. The expression of IL-4 and IL-10 decreased in splenic CD4-positive lymphocytes. Splenic CD8-positive lymphocytes expressed increased levels of IFN-gamma and IL-10 but the latter decreased sharply when diabetes occurred. The relevance of these findings to the pathogenesis of type 1 diabetes is discussed.
    Matched MeSH terms: CD4-Positive T-Lymphocytes/immunology*; CD8-Positive T-Lymphocytes/immunology*
  20. Chin SF, Cheong SK, Lim YC, Ton SH
    Malays J Pathol, 1993 Jun;15(1):49-52.
    PMID: 8277790
    The distribution of immunoregulatory cells in the peripheral blood of an individual has now been established as an important tool in helping the management of several diseases. It is necessary to set the normal ranges of these cells for the laboratory. We have undertaken in this study to establish the reference ranges for normal Malaysian adults. We found that the mean percentages of T cells, B cells, T Helper cells (CD4), T suppressor cells (CD8), NK cells and the ratio of CD4/CD8 were 70.91%, 11.38%, 38.15%, 37.76%, 17.45%, and 1.00 respectively. There was no significant difference between the sexes. In certain parameters, there was significant differences between Malay, Chinese and Indians. The Chinese and Indians were significantly different in the distribution of B cells and in the CD4/CD8 ratio. In the case of CD4 and NK cells, the Indians were different from the other two groups.
    Matched MeSH terms: T-Lymphocytes*
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