scholarly journals Immune Modulation of Platelet-Derived Mitochondria on Memory CD4+ T Cells in Humans

2020 ◽  
Vol 21 (17) ◽  
pp. 6295
Author(s):  
Haibo Yu ◽  
Wei Hu ◽  
Xiang Song ◽  
Yong Zhao

CD4+ T cells are one of the key immune cells contributing to the immunopathogenesis of type 1 diabetes (T1D). Previous studies have reported that platelet-derived mitochondria suppress the proliferation of peripheral blood mononuclear cells (PBMC). To further characterize the immune modulation of platelet-derived mitochondria, the purified CD4+ T cells were treated, respectively, with platelet-derived mitochondria. The data demonstrated that MitoTracker Deep Red-labeled platelet-derived mitochondria could directly target CD4+ T cells through C-X-C motif chemokine receptor 4 (CXCR4) and its ligand stromal cell-derived factor-1 (SDF-1), regulating the anti-CD3/CD28 bead-activated CD4+ T cells. The result was an up-regulation of Naïve and central memory (TCM) CD4+ T cells, the down-regulation of effector memory (TEM) CD4+ T cells, and modulations of cytokine productions and gene expressions. Thus, platelet-derived mitochondria have a translational potential as novel immune modulators to treat T1D and other autoimmune diseases.

Thorax ◽  
2020 ◽  
pp. thoraxjnl-2020-215520
Author(s):  
Carlos Machahua ◽  
Ivette Buendia-Roldan ◽  
Ranferi Ocaña-Guzman ◽  
María Molina-Molina ◽  
Annie Pardo ◽  
...  

BackgroundInterstitial lung abnormalities (ILA) occur in around 10% of subjects over 60 years, and are associated with a higher rate of all-cause mortality. The pathogenic mechanisms are unclear, and the putative contribution of alterations in the immune response has not been explored. Normal ageing is associated with immune deficiencies, including Naïve T-cell decrease and greater expression of the proliferative-limiting, co-inhibitory receptor killer-cell lectin-like receptor G1 (KLRG1).ObjectiveTo evaluate the frequency and activation state of different T-cell subpopulations in ILA subjects.MethodsPeripheral blood mononuclear cells were obtained from 15 individuals with ILA, 21 age-matched controls and 28 healthy young subjects. T-cells phenotype was characterised by flow cytometry, and proliferation and activation by stimulation with anti-CD3/anti-CD28 or phorbol myristate acetate/ionomycin; KLRG1 isoforms were evaluated by western blot and cytokines were quantified by ELISA and Multiplex.ResultsA significant increase of Naïve CD4+T cells together with a decrease of central and effector memory CD4+T cells was observed in ILA compared with age-matched controls. CD4+T cells from ILA subjects exhibited greater basal proliferation, which raised after anti-CD3/anti-CD28 stimulation. Additionally, a significant increase in the levels of interleukin-6 and interferon gamma was observed in isolated CD4+T cells and plasma of ILA subjects. They also displayed fewer KLRG1+/CD4+T cells with an increase of circulating E-cadherin, the ligand of KLRG1+. No changes were observed with CD8+T cell subsets.ConclusionCD4+T cells from ILA subjects are highly proliferative and show an excessive functional activity, likely related to the loss of KLRG1 expression, which may contribute to an inflammatory state and the development of ILA.


Author(s):  
Jingyi Yang ◽  
Maohua Zhong ◽  
Ejuan Zhang ◽  
Ke Hong ◽  
Qingyu Yang ◽  
...  

Abstract Although millions of patients have clinically recovered from COVID-19, little is known about the immune status of lymphocytes in these individuals. In this study, the peripheral blood mononuclear cells (PBMCs) of a clinically recovered (CR) cohort were comparatively analyzed with those of an age- and sex-matched healthy donor (HD) cohort. We found that CD8+ T cells in the CR cohort had higher numbers of effector T cells and effector memory T cells but lower Tc1 (IFN-γ+), Tc2 (IL-4+), and Tc17 (IL-17A+) cell frequencies. The CD4+ T cells of the CR cohort were decreased in frequency, especially the central memory T cell subset. Moreover, CD4+ T cells in the CR cohort showed lower PD-1 expression and had lower frequencies of Th1 (IFN-γ+), Th2 (IL-4+), Th17 (IL-17A+), and circulating follicular helper T (CXCR5+PD-1+) cells. Accordingly, the proportion of isotype-switched memory B cells (IgM−CD20hi) among B cells in the CR cohort showed a significantly lower proportion, although the level of the activation marker CD71 was elevated. For CD3−HLA-DR− lymphocytes in the CR cohort, in addition to lower levels of IFN-γ, granzyme B, and T-bet, the correlation between T-bet and IFN-γ was not observed. Additionally, by taking into account the number of days after discharge, all the phenotypes associated with reduced function did not show a tendency toward recovery within 4‒11 weeks. The remarkable phenotypic alterations in lymphocytes in the CR cohort suggest that SARS-CoV-2 infection profoundly affects lymphocytes and potentially results in dysfunction even after clinical recovery.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nirupama D. Verma ◽  
Andrew D. Lam ◽  
Christopher Chiu ◽  
Giang T. Tran ◽  
Bruce M. Hall ◽  
...  

AbstractResting and activated subpopulations of CD4+CD25+CD127loT regulatory cells (Treg) and CD4+CD25+CD127+ effector T cells in MS patients and in healthy individuals were compared. Peripheral blood mononuclear cells isolated using Ficoll Hypaque were stained with monoclonal antibodies and analysed by flow cytometer. CD45RA and Foxp3 expression within CD4+ cells and in CD4+CD25+CD127loT cells identified Population I; CD45RA+Foxp3+, Population II; CD45RA−Foxp3hi and Population III; CD45RA−Foxp3+ cells. Effector CD4+CD127+ T cells were subdivided into Population IV; memory /effector CD45RA− CD25−Foxp3− and Population V; effector naïve CD45RA+CD25−Foxp3−CCR7+ and terminally differentiated RA+ (TEMRA) effector memory cells. Chemokine receptor staining identified CXCR3+Th1-like Treg, CCR6+Th17-like Treg and CCR7+ resting Treg. Resting Treg (Population I) were reduced in MS patients, both in untreated and treated MS compared to healthy donors. Activated/memory Treg (Population II) were significantly increased in MS patients compared to healthy donors. Activated effector CD4+ (Population IV) were increased and the naïve/ TEMRA CD4+ (Population V) were decreased in MS compared to HD. Expression of CCR7 was mainly in Population I, whereas expression of CCR6 and CXCR3 was greatest in Populations II and intermediate in Population III. In MS, CCR6+Treg were lower in Population III. This study found MS is associated with significant shifts in CD4+T cells subpopulations. MS patients had lower resting CD4+CD25+CD45RA+CCR7+ Treg than healthy donors while activated CD4+CD25hiCD45RA−Foxp3hiTreg were increased in MS patients even before treatment. Some MS patients had reduced CCR6+Th17-like Treg, which may contribute to the activity of MS.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 18.2-18
Author(s):  
P. Brown ◽  
A. Anderson ◽  
B. Hargreaves ◽  
A. Morgan ◽  
J. D. Isaacs ◽  
...  

Background:The long term outcomes for patients with rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate remains the key first line disease modifying therapy for the majority of patients, with 40% achieving an ACR50 on monotherapy(1). There are at present no effective biomarkers to predict treatment response, preventing effective personalisation of therapy. A putative mechanism of action of methotrexate, the potentiation of anti-inflammatory adenosine signalling, may inform biomarker discovery. By antagonism of the ATIC enzyme in the purine synthesis pathway, methotrexate has been proposed to increase the release of adenosine moieties from cells, which exert an anti-inflammatory effect through interaction with ADORA2 receptors(2). Lower expression of CD39 (a cell surface 5-’ectonucleotidase required for the first step in the conversion of ATP to adenosine) on circulating regulatory T-Lymphocytes (Tregs) was previously identified in patients already established on methotrexate who were not responding (DAS28 >4.0 vs <3.0)(3). We therefore hypothesised that pre-treatment CD39 expression on these cells may have clinical utility as a predictor of early methotrexate efficacy.Objectives:To characterise CD39 expression in peripheral blood mononuclear cells in RA patients naïve to disease modifying therapy commencing methotrexate, and relate this expression to 4 variable DAS28CRP remission (<2.6) at 6 months.Methods:68 treatment naïve early RA patients starting methotrexate were recruited from the Newcastle Early Arthritis Clinic and followed up for 6 months. Serial blood samples were taken before and during methotrexate therapy with peripheral blood mononuclear cells isolated by density centrifugation. Expression of CD39 by major immune subsets (CD4+ and CD8+ T-cells, B-lymphocytes, natural killer cells and monocytes) was determined by flow cytometry. The statistical analysis used was binomial logistic regression with baseline DAS28CRP used as a covariate due to the significant association of baseline disease activity with treatment response.Results:Higher pre-treatment CD39 expression was observed in circulating CD4+ T-cells of patients who subsequently achieved clinical remission at 6 months versus those who did not (median fluorescence 4854.0 vs 3324.2; p = 0.0108; Figure 1-A). This CD39 expression pattern was primarily accounted for by the CD4+CD25 high sub-population (median fluorescence 9804.7 vs 6455.5; p = 0.0065; Figure 1-B). These CD25 high cells were observed to have higher FoxP3 and lower CD127 expression than their CD39 negative counterparts, indicating a Treg phenotype. No significant associations were observed with any other circulating subset. A ROC curve demonstrates the discriminative utility of differential CD39 expression in the CD4+CD25 high population for the prediction of DAS28CRP remission in this cohort, showing greater specificity than sensitivity for remission prediction(AUC: 0.725; 95% CI: 0.53 - 0.92; Figure 1-C). Longitudinally, no significant induction or suppression of the CD39 marker was observed amongst patients who did or did not achieve remission over the 6 months follow-up period.Figure 1.Six month DAS28CRP remission versus pre-treatment median fluorescence of CD39 expression on CD4+ T-cells (A); CD25 High expressing CD4+ T-cells (B); and ROC curve of predictive utility of pre-treatment CD39 expression on CD25 High CD4+ T-cells (C).Conclusion:These findings support the potential role of CD39 in the mechanism of methotrexate response. Expression of CD39 on circulating Tregs in treatment-naïve RA patients may have particular value in identifying early RA patients likely to respond to methotrexate, and hence add value to evolving multi-parameter discriminatory algorithms.References:[1]Hazlewood GS, et al. BMJ. 2016 21;353:i1777[2]Brown PM, et al. Nat Rev Rheumatol. 2016;12(12):731-742[3]Peres RS, et al. Proc Natl Acad Sci U S A. 2015;112(8):2509-2514Disclosure of Interests:None declared


2021 ◽  
Author(s):  
Emily Stephenson ◽  
◽  
Gary Reynolds ◽  
Rachel A. Botting ◽  
Fernando J. Calero-Nieto ◽  
...  

AbstractAnalysis of human blood immune cells provides insights into the coordinated response to viral infections such as severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19). We performed single-cell transcriptome, surface proteome and T and B lymphocyte antigen receptor analyses of over 780,000 peripheral blood mononuclear cells from a cross-sectional cohort of 130 patients with varying severities of COVID-19. We identified expansion of nonclassical monocytes expressing complement transcripts (CD16+C1QA/B/C+) that sequester platelets and were predicted to replenish the alveolar macrophage pool in COVID-19. Early, uncommitted CD34+ hematopoietic stem/progenitor cells were primed toward megakaryopoiesis, accompanied by expanded megakaryocyte-committed progenitors and increased platelet activation. Clonally expanded CD8+ T cells and an increased ratio of CD8+ effector T cells to effector memory T cells characterized severe disease, while circulating follicular helper T cells accompanied mild disease. We observed a relative loss of IgA2 in symptomatic disease despite an overall expansion of plasmablasts and plasma cells. Our study highlights the coordinated immune response that contributes to COVID-19 pathogenesis and reveals discrete cellular components that can be targeted for therapy.


Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Sabrina M Scroggins ◽  
Donna A Santillan ◽  
Jenna M Peterson ◽  
Nicole A Pearson ◽  
Jeremy A Sandgren ◽  
...  

The pathogenesis of preeclampsia (PreE) involves the failure of the maternal immune system to normally tolerate the pregnancy. Inflammatory cytokines are elevated in PreE-affected women with a concurrent decrease in anti-inflammatory cytokine production. Consistent with what other groups have observed in mouse models of hypertension during pregnancy and in human PreE-affected pregnancies, we observed increased inflammatory cytokine production and CD4+ T helper populations in our chronic infusion of vasopressin (AVP) mouse model of PreE. The mechanisms of immune modulation by AVP have not been elucidated. As increased T cell activity is involved in the development of PreE, the objective of this study was to investigate if CD4+ T cells express AVP receptors. Splenic CD4+ T cells were negatively purified from C57BL/6J saline and AVP-infused (24 ng/hour) dams. Expression of AVP receptors (AVPR) 1a, 1b, 2, and the aminopeptidase LNPEP (catalyzes AVP degradation) was determined via qPCR. Raw cycle threshold (Ct) values were normalized (ΔCt) against the 18S rRNA endogenous control. Mouse CD4+ T cells express all AVP receptors and LNPEP. By ANOVA, AVPR2 is the highest expressed receptor in CD4+ T cells from saline (N=7, p=0.002) and AVP-infused (N=10, p<0.0001) dams. Human maternal mononuclear cells, obtained from the University of Iowa Maternal-Fetal Tissue Bank (IRB #200910784) from control and PreE-affected women, were similarly analyzed. As in mouse CD4+ T cells, human control (N=27, p<0.0001) and PreE-affected (N=26, p<0.0001) CD4+ T cells most highly expressed AVPR2. AVPR1a was also highly expressed while AVPR1b was the least expressed. CD4+ T cells isolated from human PreE-affected women expressed significantly lower AVPR1a (10.0±0.3 N=27 vs. 11.1±0.2 N=0.23, p=0.009) and increased LNPEP (17.2±0.5 N=27 vs. 15.1±0.3 N=26, p=0.001) than controls. Here, we demonstrate CD4+ T cells, both mouse and human, express AVP receptors and that 1a and 2 are highest expressed. Although the actions of AVP on the vasculature are primarily mediated through AVPR1a, these data suggest AVP may differentially act through AVPR1a to mediate immune responses during PreE.


2000 ◽  
Vol 191 (3) ◽  
pp. 551-560 ◽  
Author(s):  
Mark R. Alderson ◽  
Teresa Bement ◽  
Craig H. Day ◽  
Liqing Zhu ◽  
David Molesh ◽  
...  

Development of a subunit vaccine for Mycobacterium tuberculosis (Mtb) is likely to be dependent on the identification of T cell antigens that induce strong proliferation and interferon γ production from healthy purified protein derivative (PPD)+ donors. We have developed a sensitive and rapid technique for screening an Mtb genomic library expressed in Escherichia coli using Mtb-specific CD4+ T cells. Using this technique, we identified a family of highly related Mtb antigens. The gene of one family member encodes a 9.9-kD antigen, termed Mtb9.9A. Recombinant Mtb9.9A protein, expressed and purified from E. coli, elicited strong T cell proliferation and IFN-γ production by peripheral blood mononuclear cells from PPD+ but not PPD− individuals. Southern blot analysis and examination of the Mtb genome sequence revealed a family of highly related genes. A T cell line from a PPD+ donor that failed to react with recombinant Mtb9.9A recognized one of the other family members, Mtb9.9C. Synthetic peptides were used to map the T cell epitope recognized by this line, and revealed a single amino acid substitution in this region when compared with Mtb9.9A. The direct identification of antigens using T cells from immune donors will undoubtedly be critical for the development of vaccines to several intracellular pathogens.


Author(s):  
Derek J Hanson ◽  
Hu Xie ◽  
Danielle M Zerr ◽  
Wendy M Leisenring ◽  
Keith R Jerome ◽  
...  

Abstract We sought to determine whether donor-derived human herpesvirus (HHV) 6B–specific CD4+ T-cell abundance is correlated with HHV-6B detection after allogeneic hematopoietic cell transplantation. We identified 33 patients who received HLA-matched, non–T-cell–depleted, myeloablative allogeneic hematopoietic cell transplantation and underwent weekly plasma polymerase chain reaction testing for HHV-6B for 100 days thereafter. We tested donor peripheral blood mononuclear cells for HHV-6B–specific CD4+ T cells. Patients with HHV-6B detection above the median peak viral load (200 copies/mL) received approximately 10-fold fewer donor-derived total or HHV-6B–specific CD4+ T cells than those with peak HHV-6B detection at ≤200 copies/mL or with no HHV-6B detection. These data suggest the importance of donor-derived immunity for controlling HHV-6B reactivation.


Author(s):  
Yonghong Yang ◽  
Cui Zhang ◽  
Dehuai Jing ◽  
Heng He ◽  
Xiaoyu Li ◽  
...  

Abstract Background Inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn’s disease (CD), are chronic inflammatory disorders. As is well known, interferon regulatory factor (IRF) 5 is closely associated with the pathogenesis of various inflammatory diseases. But the exact role of IRF5 in IBD remains unclear. Methods In this study, we detected IRF5 expression in peripheral blood mononuclear cells (PBMCs) and inflamed mucosa from IBD patients by immunohistochemistry, western blot, and quantitative real-time polymerase chain reaction. Peripheral blood CD4+ T cells were stimulated with inflammatory cytokines and transfected by lentivirus. Results In active IBD patients, the expression of IRF5 in PBMCs and inflamed colonic tissues was obviously increased and significantly associated with disease activity. Ectopic overexpression of IRF5 could promote the differentiation of IBD CD4+ T cells into Th1 and Th17 cells by regulating T-bet and RAR related orphan receptor C, whereas knockdown of IRF5 had the opposite effects. Tumor necrosis factor (TNF)-α upregulated expression of IRF5 in CD4+ T cells, but anti-TNF treatment with infliximab could markedly reduce IRF5 expression in CD4+ T cells and intestinal mucosa of CD patients. Conclusion Our study reveals a novel mechanism that IRF5 levels are correlated with disease activity in IBD and might function as a possible marker for the management of IBD via regulating Th1 and Th17 immune responses and cytokine production.


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