MyMedR

Displaying all 10 publications

Abstract:

Sort:

Fulltext Reduced CD4+ terminally differentiated effector memory T cells in moderate-severe house dust mites sensitized allergic rhinitis patients

Sani MM, Ashari NSM, Abdullah B, Wong KK, Musa KI, Mohamud R, et al.

Asian Pac J Allergy Immunol, 2019 Sep;37(3):138-146.
PMID: 29981564 DOI: 10.12932/AP-191217-0220

BACKGROUND: Terminally differentiated effector memory (TEMRA) T cells exert potent effector function after activation. The proportions of CD4+ T cell subsets especially memory cells in allergic rhinitis (AR) patients sensitized to house dust mites (HDMs) have not been extensively studied.
OBJECTIVE: This study aimed to compare the mean percentages and absolute counts of CD4+ memory T cell subsets between: (i) non-allergic controls and AR patients; (ii) mild AR patients and moderate-severe AR patients.
METHODS: Sensitization to Dermatophagoides farinae and Dermatophagoides pteronyssinus were determined in 33 non -allergic controls, 28 mild AR and 29 moderate-severe AR patients. Flow cytometry was used to determine the percentage of CD4+ na?ve (TN; CD45RA+CCR7+), central memory (TCM; CD45RA-CCR7+), effector memory (TEM; CD45RA-CCR7-) and TEMRA (CD45RA+CCR7-) T cells from the peripheral blood. The absolute counts of CD4+ T cell subsets were obtained by dual platform method from flow cytometer and hematology analyzer.
RESULTS: There were no significant differences in the mean percentages and absolute counts of CD4+ T cell subsets between non-allergic controls and AR patients sensitized to HDMs. However, there were significant reduction in the mean percentage (p=0.0307) and absolute count (p=0.0309) of CD4+ TEMRA cells in moderate-severe AR patients compared to mild AR patients sensitized to HDMs and 13/24 (54.2%) moderate-severe AR patients sensitized to HDMs had persistent symptoms.
CONCLUSION: Reduction in the mean percentage and absolute count of CD4+CD45RA+CCR7- TEMRA cells were observed in moderate-severe AR patients compared to mild AR patients in our population of AR patients sensitized to HDMs.

Matched MeSH terms: T-Lymphocyte Subsets/immunology*
Fulltext CD3+CD4+gp130+ T Cells Are Associated With Worse Disease Activity in Systemic Lupus Erythematosus Patients

Mohd Shukri ND, Farah Izati A, Wan Ghazali WS, Che Hussin CM, Wong KK

Front Immunol, 2021;12:675250.
PMID: 34149710 DOI: 10.3389/fimmu.2021.675250

The receptors for IL-35, IL-12Rβ2 and gp130, have been implicated in the inflammatory pathophysiology of autoimmune diseases. In this study, we set out to investigate the serum IL-35 levels and the surface levels of IL-12Rβ2 and gp130 in CD3+CD4+, CD3+CD4─ and CD3─CD4─ lymphocyte subpopulations in systemic lupus erythematosus (SLE) patients (n=50) versus healthy controls (n=50). The potential T cell subsets associated with gp130 transcript (i.e. IL6ST) expression in CD4+ T cells of SLE patients was also examined in publicly-available gene expression profiling (GEP) datasets. Here, we report that serum IL-35 levels were significantly higher in SLE patients than healthy controls (p=0.038) but it was not associated with SLEDAI-2K scores. The proportions of IL-12Rβ2+ and gp130+ cells in SLE patients did not differ significantly with those of healthy controls in all lymphocyte subpopulations investigated. Essentially, higher SLEDAI-2K scores were positively correlated with increased proportion of gp130+ cells, but not IL-12Rβ2+ cells, on CD3+CD4+ T cells (r=0.425, p=0.002, q=0.016). Gene Set Enrichment Analysis (GSEA) of a GEP dataset of CD4+ T cells isolated from SLE patients (n=8; GSE4588) showed that IL6ST expression was positively associated with genes upregulated in CD4+ T cells vs myeloid or B cells (q<0.001). In an independent GEP dataset of CD4+ T cells isolated from SLE patients (n=9; GSE1057), IL6ST expression was induced upon anti-CD3 stimulation, and that Treg, TCM and CCR7+ T cells gene sets were significantly enriched (q<0.05) by genes highly correlated with IL6ST expression (n=92 genes; r>0.75 with IL6ST expression) upon anti-CD3 stimulation in these SLE patients. In conclusion, gp130 signaling in CD3+CD4+ T cell subsets may contribute to increased disease activity in SLE patients, and it represents a promising therapeutic target for inhibition in the disease.

Matched MeSH terms: T-Lymphocyte Subsets/immunology*
The inhibition of human T cell proliferation by the caspase inhibitor z-VAD-FMK is mediated through oxidative stress

Rajah T, Chow SC

Toxicol Appl Pharmacol, 2014 Jul 15;278(2):100-6.
PMID: 24768707 DOI: 10.1016/j.taap.2014.04.014

The caspase inhibitor benzyloxycarbony (Cbz)-l-Val-Ala-Asp (OMe)-fluoromethylketone (z-VAD-FMK) has recently been shown to inhibit T cell proliferation without blocking caspase-8 and caspase-3 activation in primary T cells. We showed in this study that z-VAD-FMK treatment leads to a decrease in intracellular glutathione (GSH) with a concomitant increase in reactive oxygen species (ROS) levels in activated T cells. The inhibition of anti-CD3-mediated T cell proliferation induced by z-VAD-FMK was abolished by the presence of low molecular weight thiols such as GSH, N-acetylcysteine (NAC) and l-cysteine, whereas d-cysteine which cannot be metabolised to GSH has no effect. These results suggest that the depletion of intracellular GSH is the underlying cause of z-VAD-FMK-mediated inhibition of T cell activation and proliferation. The presence of exogenous GSH also attenuated the inhibition of anti-CD3-induced CD25 and CD69 expression mediated by z-VAD-FMK. However, none of the low molecular weight thiols were able to restore the caspase-inhibitory properties of z-VAD-FMK in activated T cells where caspase-8 and caspase-3 remain activated and processed into their respective subunits in the presence of the caspase inhibitor. This suggests that the inhibition of T cell proliferation can be uncoupled from the caspase-inhibitory properties of z-VAD-FMK. Taken together, the immunosuppressive effects in primary T cells mediated by z-VAD-FMK are due to oxidative stress via the depletion of GSH.

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Keloids - the sebum hypothesis revisited

Fong EP, Bay BH

Med Hypotheses, 2002 Apr;58(4):264-9.
PMID: 12027517

The aetiology of the keloid scar has not been completely elucidated. Numerous hypotheses have been proposed in the past to explain the unusual characteristics of the keloid scar. While we do know that there is excessive and ongoing collagen-deposition, the exact triggering stimulus is a subject of conjecture. We present some of our photographic records of keloids and electron microscopic findings of keloid edges and reiterate the sebum hypothesis. We also attempt to explain the features of keloids in the light of the present knowledge of immunology and cell biology.

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Chronic mucocutaneous candidiasis with deficient CD2 (E receptor) but normal CD3 mononuclear cells

Noh LM, Hussein SH, Sukumaran KD, Rose I, Abdullah N

J Clin Lab Immunol, 1991 Jun;35(2):89-93.
PMID: 1688166

A case of chronic mucocutaneous candidiasis in a Malaysian child who subsequently developed disseminated tuberculosis and toxoplasmosis is described. The phenotype of her peripheral blood mononuclear cells showed discordance for her T cell markers. The presence of a subpopulation of CD2-/CD3+ mononuclear cells leading to an immunodeficiency state is consistent with failure of activation of CD2-mediated alternative pathway resulting in immunodeficiency. Such abnormal CD2-/CD3+ subpopulations have been described in lepromatous leprosy and foetal abortuses.

Matched MeSH terms: T-Lymphocyte Subsets/immunology*
Fulltext CD4:CD8 ratio comparison between cohorts of HIV-positive Asians and Caucasians upon commencement of antiretroviral therapy

Petoumenos K, Choi JY, Hoy J, Kiertiburanakul S, Ng OT, Boyd M, et al.

Antivir Ther, 2017;22(8):659-668.
PMID: 28291735 DOI: 10.3851/IMP3155

BACKGROUND: In the era of effective antiretroviral treatment (ART) CD4:CD8 ratio is proposed as a potential marker for HIV-positive (HIV+) patients at increased risk for non-AIDS comorbidities. The current study aims to compare CD4:CD8 ratio between Asian and Caucasian HIV+ patients.
METHODS: HIV+ patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) meeting specific criteria were included. In these analyses Asian and Caucasian status were defined by cohort. Factors associated with a low CD4:CD8 ratio (cutoff <0.2) prior to ART commencement, and with achieving a normal CD4:CD8 ratio (>1) at 12 and 24 months post ART commencement were assessed using logistic regression.
RESULTS: There were 591 patients from AHOD and 2,620 patients from TAHOD who met the inclusion criteria. TAHOD patients had a significantly (P<0.001) lower odds of having a baseline (prior to ART initiation) CD4:CD8 ratio greater than 0.2. After 12 months of ART, AHOD patients were more than twice as likely to achieve a normal CD4:CD8 ratio compared to TAHOD patients (15% versus 6%). However, after adjustment for confounding factors there was no significant difference between cohorts in the odds of achieving a CD4:CD8 ratio >1 (P=0.475).
CONCLUSIONS: We found a significantly lower CD4:CD8 ratio prior to commencing ART in TAHOD compared to AHOD even after adjusting for confounders. However, after adjustment, there was no significant difference between the cohorts in odds of achieving normal ratio. Baseline CD4+ and CD8+ counts seem to be the main driver for this difference between these two populations.

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Fulltext CD4+CD25hiCD127low regulatory T cells are increased in oral squamous cell carcinoma patients

Lim KP, Chun NA, Ismail SM, Abraham MT, Yusoff MN, Zain RB, et al.

PLoS One, 2014;9(8):e103975.
PMID: 25153698 DOI: 10.1371/journal.pone.0103975

Regulatory T cells (Tregs), a subset of CD4+ T cells plays a pivotal role in regulating the immune system. An increase in Treg numbers enables cancer progression by dampening the immune system and allowing tumor cells to evade immune detection and destruction. An increase in Treg numbers and expression of inhibitory cytokines including TGF-β and IL-10 are mechanisms by which Tregs exert their immune suppressive function. However, the presence of Tregs and inhibitory cytokines in oral cancer patients is still unclear. In this study, the presence of circulating Tregs in 39 oral cancer patients and 24 healthy donors was examined by studying the presence of the CD4+CD25hiCD127low cell population in their peripheral blood mononuclear cells using flow cytometry. Serum levels of TGF-β and IL-10 were measured by ELISA. T cell subsets of OSCC patients were found to differ significantly from healthy donors where a decrease in CD8+ cytotoxic T cells and an increase in Tregs (CD4+CD25hiCD127low) were observed. Further, the ratio of CD8+ T cells/Tregs was also decreased in patients compared to healthy donors. The presence of Tregs was accompanied by a decrease in IL-10 but not TGF-β secretion in OSCC patients when compared to donors; in addition, the analysis also revealed that an increased presence of Tregs was accompanied by better patient survival. Amongst OSCC patients, smokers had significantly higher levels of TGF-β. It is apparent that the immune system is compromised in OSCC patients and the characterization of the Treg subpopulation could form a basis for improving our understanding of the perturbations in the immune system that occur during OSCC tumorigenesis.

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Immunomodulatory activity of polyphenols derived from Cassia auriculata flowers in aged rats

John CM, Sandrasaigaran P, Tong CK, Adam A, Ramasamy R

Cell Immunol, 2011;271(2):474-9.
PMID: 21924708 DOI: 10.1016/j.cellimm.2011.08.017

The immunomodulatory activity of Cassia auriculata (CA)-derived polyphenols was tested on aged rats. Rats (24-26 months old) were given CA polyphenols supplementation at doses of 25, 50, and 100 mg/kg for 28 days. Flow cytometry analysis of CA polyphenols-treated aged rats showed increased T and B cells percentage along with enhanced proliferation of splenocytes in both resting and LPS-stimulated cells. Increased percentage of pan T cells is further supported by an elevation of CD4+, CD8+, and CD4+CD25+ regulatory cells. In terms of innate immune cell activity, CA polyphenol supplementation reduced the oxidative burst activity of neutrophils in response to PMA and Escherichia coli activation. Our results collectively show that polyphenols derived from CA boost T cell immunity by increasing the number of T cells and its sensitivity towards stimulants and decreasing ROS production by neutrophils that could potentially harm multiple biological systems in aged individuals.

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Proportions of circulating T cells with a regulatory cell phenotype increase with HIV-associated immune activation and remain high on antiretroviral therapy

Lim A, Tan D, Price P, Kamarulzaman A, Tan HY, James I, et al.

AIDS, 2007 Jul 31;21(12):1525-34.
PMID: 17630546

To examine the relationships between blood CD4 natural regulatory T (Treg) cells, plasma HIV RNA level, CD4 T-cell count and immune activation in untreated HIV-infected patients and immunodeficient patients beginning antiretroviral therapy (ART), using a novel phenotype to define Treg cells (CD25CD127CD4). Data were compared with established Treg cell markers (FoxP3, CTLA-4 and GITR).

Matched MeSH terms: T-Lymphocyte Subsets/immunology
Fulltext Human CD3+ T-Cells with the Anti-ERBB2 Chimeric Antigen Receptor Exhibit Efficient Targeting and Induce Apoptosis in ERBB2 Overexpressing Breast Cancer Cells

Munisvaradass R, Kumar S, Govindasamy C, Alnumair KS, Mok PL

Int J Mol Sci, 2017 Sep 08;18(9).
PMID: 28885562 DOI: 10.3390/ijms18091797

Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non-transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours.

Matched MeSH terms: T-Lymphocyte Subsets/immunology*