scholarly journals Expression Cloning of an Immunodominant Family of Mycobacterium tuberculosis Antigens Using Human Cd4+ T Cells

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.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1730-1730
Author(s):  
Izumi Masamoto ◽  
Sawako Horai ◽  
Tomohiro Kozako ◽  
Makoto Yoshimitsu ◽  
Junko Niimoto ◽  
...  

Abstract Abstract 1730 Human T-lymphotropic virus type-1(HTLV-1) is the causative agent of adult T cell leukemia/lymphoma (ATL). HTLV-1 infected T cell growth or leukemogenesis in ATL is controlled by various host immune surveillance systems. Among them, CD70 on HTLV-1 infected T cells coupled with CD27 on virus specific cytotoxic T cells has been suggested to play an important role in ATL leukemogenesis. The CD70 molecule is the only known ligand for CD27, a member of the tumor necrosis factor (TNF) receptor superfamily 7. This negative immunoregulatory pathway downregulates cytotoxic T lymphocyte activity against CD70-expressing virus infected cells. In the present study, we examined CD70 expression on primary lymphocytes of HTLV-1 carriers and ATL patients, its relationship with HTLV-1 Tax protein expression, and the effect on CTL induction. CD70 expression was higher on peripheral blood mononuclear cells (PBMCs) of HTLV-1 infected carriers compared with healthy donors (p = 0.021, n = 21, Mann-Whitney U test), and higher in ATL patients compared to carriers (p = 0.045, n = 38, Mann-Whitney U test). CD70 expression may be observed in CD4 T cells, as well as B cells, but not in CD8 T cells or monocytes. CD70 expression in CD4 T cells is related to HTLV-1 infection, because of increased detection of HTLV-1 Tax protein during over night culture of CD70-expressing cells. Experiments using an ATL cell line, in which Tax expression is inducible by doxycycline stimulation, demonstrated enhanced CD70 expression when Tax protein was induced in HTLV-1 infected cells. Anti-CD70 antibody enhanced CD107a mobilization, a marker of recent cytotoxic degranulation, in HTLV-1 Tax specific CTLs in PBMCs from asymptomatic carriers in vitro, suggesting that the CD70/CD27 pathway plays an important role in the immune response to HTLV-1 infection in carriers, as well as ATL patients. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 23 (4) ◽  
pp. 282-293 ◽  
Author(s):  
Vijaya Satchidanandam ◽  
Naveen Kumar ◽  
Sunetra Biswas ◽  
Rajiv S. Jumani ◽  
Chandni Jain ◽  
...  

ABSTRACTWe previously reported that Rv1860 protein fromMycobacterium tuberculosisstimulated CD4+and CD8+T cells secreting gamma interferon (IFN-γ) in healthy purified protein derivative (PPD)-positive individuals and protected guinea pigs immunized with a DNA vaccine and a recombinant poxvirus expressing Rv1860 from a challenge with virulentM. tuberculosis. We now show Rv1860-specific polyfunctional T (PFT) cell responses in the blood of healthy latentlyM. tuberculosis-infected individuals dominated by CD8+T cells, using a panel of 32 overlapping peptides spanning the length of Rv1860. Multiple subsets of CD8+PFT cells were significantly more numerous in healthy latently infected volunteers (HV) than in tuberculosis (TB) patients (PAT). The responses of peripheral blood mononuclear cells (PBMC) from PAT to the peptides of Rv1860 were dominated by tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) secretions, the former coming predominantly from non-T cell sources. Notably, the pattern of the T cell response to Rv1860 was distinctly different from those of the widely studiedM. tuberculosisantigens ESAT-6, CFP-10, Ag85A, and Ag85B, which elicited CD4+T cell-dominated responses as previously reported in other cohorts. We further identified a peptide spanning amino acids 21 to 39 of the Rv1860 protein with the potential to distinguish latent TB infection from disease due to its ability to stimulate differential cytokine signatures in HV and PAT. We suggest that a TB vaccine carrying these and other CD8+T-cell-stimulating antigens has the potential to prevent progression of latentM. tuberculosisinfection to TB disease.


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.


2011 ◽  
Vol 286 (27) ◽  
pp. 24508-24518 ◽  
Author(s):  
Hui Peng ◽  
Xisheng Wang ◽  
Peter F. Barnes ◽  
Hua Tang ◽  
James C. Townsend ◽  
...  

We reported previously that the early secreted antigenic target of 6 kDa (ESAT-6) from Mycobacterium tuberculosis directly inhibits human T cell IFN-γ production and proliferation in response to stimulation with anti-CD3 and anti-CD28. To determine the mechanism of this effect, we treated T cells with kinase inhibitors before stimulation with ESAT-6. Only the p38 MAPK inhibitor, SB203580, abrogated ESAT-6-mediated inhibition of IFN-γ production in a dose-dependent manner. SB203580 did not reverse ESAT-6-mediated inhibition of IL-17 and IL-10 production, suggesting a specific effect of SB203580 on IFN-γ production. SB203580 did not act through inhibition of AKT (PKB) as an AKT inhibitor did not affect ESAT-6 inhibition of T cell IFN-γ production and proliferation. ESAT-6 did not reduce IFN-γ production by expanding FoxP3+ T regulatory cells. Incubation of T cells with ESAT-6 induced phosphorylation and increased functional p38 MAPK activity, but not activation of ERK or JNK. Incubation of peripheral blood mononuclear cells with ESAT-6 induced activation of p38 MAPK, and inhibition of p38 MAPK with SB203580 reversed ESAT-6 inhibition of M. tuberculosis-stimulated IFN-γ production by peripheral blood mononuclear cells from subjects with latent tuberculosis infection. Silencing of p38α MAPK with siRNA rendered T cells resistant to ESAT-6 inhibition of IFN-γ production. Taken together, our results demonstrate that ESAT-6 inhibits T cell IFN-γ production in a p38 MAPK-dependent manner.


2019 ◽  
Vol 116 (48) ◽  
pp. 24242-24251 ◽  
Author(s):  
Kosuke Hashimoto ◽  
Tsukasa Kouno ◽  
Tomokatsu Ikawa ◽  
Norihito Hayatsu ◽  
Yurina Miyajima ◽  
...  

Supercentenarians, people who have reached 110 y of age, are a great model of healthy aging. Their characteristics of delayed onset of age-related diseases and compression of morbidity imply that their immune system remains functional. Here we performed single-cell transcriptome analysis of 61,202 peripheral blood mononuclear cells (PBMCs), derived from 7 supercentenarians and 5 younger controls. We identified a marked increase of cytotoxic CD4 T cells (CD4 cytotoxic T lymphocytes [CTLs]) as a signature of supercentenarians. Furthermore, single-cell T cell receptor sequencing of 2 supercentenarians revealed that CD4 CTLs had accumulated through massive clonal expansion, with the most frequent clonotypes accounting for 15 to 35% of the entire CD4 T cell population. The CD4 CTLs exhibited substantial heterogeneity in their degree of cytotoxicity as well as a nearly identical transcriptome to that of CD8 CTLs. This indicates that CD4 CTLs utilize the transcriptional program of the CD8 lineage while retaining CD4 expression. Indeed, CD4 CTLs extracted from supercentenarians produced IFN-γ and TNF-α upon ex vivo stimulation. Our study reveals that supercentenarians have unique characteristics in their circulating lymphocytes, which may represent an essential adaptation to achieve exceptional longevity by sustaining immune responses to infections and diseases.


Blood ◽  
2000 ◽  
Vol 96 (5) ◽  
pp. 1994-1995 ◽  
Author(s):  
Masako Moriuchi ◽  
Hiroyuki Moriuchi

Abstract Although it is widely believed that viral clearance is mediated principally by the destruction of infected cells by cytotoxic T cells, noncytolytic antiviral activity of CD8+ T cells may play a role in preventing the progression to disease in infections with immunodeficiency viruses and hepatitis B virus. We demonstrate here that (1) replication of human T-lymphotropic virus type I (HTLV-I) is more readily detected from CD8+ T-cell–depleted (CD8−) peripheral blood mononuclear cells (PBMCs) of healthy HTLV-I carriers than from unfractionated PBMCs, (2) cocultures of CD8− PBMCs with autologous or allogeneic CD8+ T cells suppressed HTLV-I replication, and (3) CD8+ T-cell anti-HTLV-I activity is not abrogated intrans-well cultures in which CD8+ cells are separated from CD8− PBMCs by a permeable membrane filter. These results suggest that class I-unrestricted noncytolytic anti–HTLV-I activity is mediated, at least in part by a soluble factor(s), and may play a role in the pathogenesis of HTLV-I infection.


Author(s):  
L. Sams ◽  
S. Kruger ◽  
V. Heinemann ◽  
D. Bararia ◽  
S. Haebe ◽  
...  

Abstract Purpose This pilot study aimed on generating insight on alterations in circulating immune cells during the use of FOLFIRINOX and gemcitabine/nab-paclitaxel in pancreatic ductal adenocarcinoma (PDAC). Patients and methods Peripheral blood mononuclear cells were isolated before and 30 days after initiation of chemotherapy from 20 patients with advanced PDAC. Regulatory T cells (FoxP3+) and immune checkpoints (PD-1 and TIM-3) were analyzed by flow cytometry and immunological changes were correlated with clinical outcome. Results Heterogeneous changes during chemotherapy were observed in circulating T-cell subpopulations with a pronounced effect on PD-1+ CD4+/CD8+ T cells. An increase in FoxP3+ or PD-1+ T cells had no significant effect on survival. An increase in TIM3+/CD8+ (but not TIM3+/CD4+) T cells was associated with a significant inferior outcome: median progression-free survival in the subgroup with an increase of TIM-3+/CD8+ T cells was 6.0 compared to 14.0 months in patients with a decrease/no change (p = 0.026); corresponding median overall survival was 13.0 and 20.0 months (p = 0.011), respectively. Conclusions Chemotherapy with FOLFIRNOX or gemcitabine/nab-paclitaxel induces variable changes in circulating T-cell populations that may provide prognostic information in PDAC.


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


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