Alkylamines cause Vγ9Vδ2 T-cell activation and proliferation by inhibiting the mevalonate pathway

Blood ◽  
2006 ◽  
Vol 107 (2) ◽  
pp. 651-654 ◽  
Author(s):  
Keith Thompson ◽  
Javier Rojas-Navea ◽  
Michael J. Rogers

AbstractThree general classes of small, nonpeptide “antigens” activate Vγ9Vδ2 T cells: pyrophosphomonoesters, such as isopentenyl diphosphate (IPP), nitrogen-containing bisphosphonates (N-BPs), and alkylamines. However, we have shown recently that N-BPs indirectly activate Vγ9Vδ2 T cells as a consequence of inhibition of farnesyl diphosphate synthase (a key enzyme of the mevalonate pathway) and the intracellular accumulation of IPP. We now show that alkylamines activate Vγ9Vδ2 T cells by the same mechanism. Alkylamines were found to be weak inhibitors of farnesyl diphosphate synthase and caused accumulation of unprenylated Rap1A in peripheral blood mononuclear cells and macrophages, indicative of inhibition of the mevalonate pathway. Furthermore, as with N-BPs, the stimulatory effect of the alkylamines on Vγ9Vδ2T cells was abrogated by simultaneous treatment with mevastatin. These findings suggest that only pyrophosphomonoesters such as IPP are true Vγ9Vδ2 T-cell agonists, whereas alkylamines and N-BPs indirectly activate Vγ9Vδ2 T cells through a common mechanism involving the accumulation of IPP.

2005 ◽  
Vol 12 (7) ◽  
pp. 861-866 ◽  
Author(s):  
Elke Lainka ◽  
Michael S. Hershfield ◽  
Ines Santisteban ◽  
Pawan Bali ◽  
Annette Seibt ◽  
...  

ABSTRACT We describe the effects of polyethylene glycol-conjugated adenosine deaminase (ADA) replacement therapy on lymphocyte counts, activation, apoptosis, proliferation, and cytokine secretion in a 14-month-old girl with “delayed-onset” ADA deficiency and marked immunodysregulation. Pretreatment lymphopenia affected T cells (CD4, 150/μl; CD8, 459/μl), B cells (16/μl), and NK cells (55/μl). T cells were uniformly activated and largely apoptotic (CD4, 59%; CD8, 82%); and T-cell-dependent cytokine levels in plasma were elevated, including the levels of interleukin 2 (IL-2; 26 pg/ml), IL-4 (81 pg/ml), IL-5 (46 pg/ml), gamma interferon (1,430 pg/ml), tumor necrosis factor alpha (210 pg/ml), and IL-10 (168 pg/ml). Mitogen-stimulated peripheral blood mononuclear cells show reduced IL-2 secretion and proliferation. During the first 5 months of therapy there was clinical improvement and partial immune reconstitution, with nearly normal lymphocyte subset numbers, reduced T-cell activation and CD4-cell apoptosis, and decreased plasma cytokine levels. In parallel, IL-2 secretion and the lymphocyte mitogenic response improved. Between 4 and 7 months, immunoglobulin G antibodies to bovine ADA developed and resulted in the complete reversal of immune recovery.


Author(s):  
M E Jacobs ◽  
J N Pouw ◽  
M A Olde Nordkamp ◽  
T R D J Radstake ◽  
E F A Leijten ◽  
...  

Abstract Background Signals at the contact site of antigen-presenting cells (APCs) and T cells help orchestrate the adaptive immune response. CD155 on APCs can interact with the stimulatory receptor DNAM1 or inhibitory receptor TIGIT on T cells. The CD155/DNAM1/TIGIT axis is under extensive investigation as immunotherapy target in inflammatory diseases including cancer, chronic infection and autoimmune diseases. We investigated a possible role for CD155/DNAM1/TIGIT signaling in psoriatic disease. Methods By flow cytometry we analyzed peripheral blood mononuclear cells of patients with psoriasis (n=20) or psoriatic arthritis (n=21), and healthy individuals (n=7). We measured CD155, TIGIT and DNAM1 expression on leukocyte subsets and compared activation-induced cytokine production between CD155-positive and -negative APCs. We assessed the effects of TIGIT and DNAM1 blockade on T cell activation, and related the expression of CD155/DNAM1/TIGIT axis molecules to measures of disease activity. Results High CD155 expression associates with TNF production in myeloid and plasmacytoid dendritic cells (DC). In CD1c+ myeloid DC, activation-induced CD155 expression associates with increased HLA-DR expression. CD8 T cells - but not CD4 T cells - express high levels of TIGIT. DNAM1 blockade decreases T cell pro-inflammatory cytokine production, while TIGIT blockade increased T cell proliferation. Finally, T cell TIGIT expression shows an inverse correlation with inflammation biomarkers in psoriatic disease. Conclusion CD155 is increased on pro-inflammatory APCs, while the receptors DNAM1 and TIGIT expressed on T cells balance the inflammatory response by T cells. In psoriatic disease, low TIGIT expression on T cells is associated with systemic inflammation.


Author(s):  
Erica Franceschini ◽  
Sara De Biasi ◽  
Margherita Digaetano ◽  
Elena Bianchini ◽  
Domenico Lo Tartaro ◽  
...  

Abstract Background In patients undergoing orthotopic liver transplant (OLT), immunosuppressive treatment is mandatory and infections are leading causes of morbidity/mortality. Thus, it is essential to understand the functionality of cell-mediated immunity after OLT. The aim of the study was to identify changes in T-cell phenotype and polyfunctionality in human immunodeficiency virus–positive (HIV+) and –negative (HIV–) patients undergoing immunosuppressive treatment after OLT. Methods We studied peripheral blood mononuclear cells from 108 subjects divided into 4 groups of 27: HIV+ transplanted patients, HIV– transplanted patients, HIV+ nontransplanted patients, and healthy subjects. T-cell activation, differentiation, and cytokine production were analyzed by flow cytometry. Results Median age was 55 years (interquartile range, 52–59 years); the median CD4 count in HIV+ patients was 567 cells/mL, and all had undetectable viral load. CD4+ and CD8+ T-cell subpopulations showed different distributions between HIV+ and HIV– OLT patients. A cluster representing effector cells expressing PD1 was abundant in HIV– transplanted patients and they were characterized by higher levels of CD4+ T cells able to produce interferon-γ and tumor necrosis factor–α. Conclusions HIV– transplanted patients have more exhausted or inflammatory T cells compared to HIV+ transplanted patients, suggesting that patients who have already experienced a form of immunosuppression due to HIV infection respond differently to anti-rejection therapy.


2020 ◽  
Vol 27 (11) ◽  
pp. 3196-3207 ◽  
Author(s):  
Chiara Agrati ◽  
Alessandra Sacchi ◽  
Veronica Bordoni ◽  
Eleonora Cimini ◽  
Stefania Notari ◽  
...  

Abstract SARS-CoV-2 is associated with a 3.4% mortality rate in patients with severe disease. The pathogenesis of severe cases remains unknown. We performed an in-depth prospective analysis of immune and inflammation markers in two patients with severe COVID-19 disease from presentation to convalescence. Peripheral blood from 18 SARS-CoV-2-infected patients, 9 with severe and 9 with mild COVID-19 disease, was obtained at admission and analyzed for T-cell activation profile, myeloid-derived suppressor cells (MDSCs) and cytokine profiles. MDSC functionality was tested in vitro. In four severe and in four mild patients, a longitudinal analysis was performed daily from the day of admission to the early convalescent phase. Early after admission severe patients showed neutrophilia, lymphopenia, increase in effector T cells, a persisting higher expression of CD95 on T cells, higher serum concentration of IL-6 and TGF-β, and a cytotoxic profile of NK and T cells compared with mild patients, suggesting a highly engaged immune response. Massive expansion of MDSCs was observed, up to 90% of total circulating mononuclear cells in patients with severe disease, and up to 25% in the patients with mild disease; the frequency decreasing with recovery. MDSCs suppressed T-cell functions, dampening excessive immune response. MDSCs decline at convalescent phase was associated to a reduction in TGF-β and to an increase of inflammatory cytokines in plasma samples. Substantial expansion of suppressor cells is seen in patients with severe COVID-19. Further studies are required to define their roles in reducing the excessive activation/inflammation, protection, influencing disease progression, potential to serve as biomarkers of disease severity, and new targets for immune and host-directed therapeutic approaches.


Blood ◽  
2006 ◽  
Vol 109 (9) ◽  
pp. 3873-3880 ◽  
Author(s):  
Lesley White ◽  
Subramaniam Krishnan ◽  
Natasa Strbo ◽  
Huanliang Liu ◽  
Michael A. Kolber ◽  
...  

Abstract An urgent need exists to devise strategies to augment antiviral immune responses in patients with HIV who are virologically well controlled and immunologically stable on highly active antiretroviral therapy (HAART). The objective of this study was to compare the immunomodulatory effects of the cytokines interleukin (IL)–21 with IL-15 on CD8 T cells in patients with HIV RNA of less than 50 copies/mL and CD4 counts greater than 200 cells/mm.3 Patient CD8 T cells displayed skewed maturation and decreased perforin expression compared with healthy controls. Culture of freshly isolated patient peripheral-blood mononuclear cells (PBMCs) for 5 hours to 5 days with IL-21 resulted in up-regulation of perforin in CD8 T cells, including memory and effector subsets and virus-specific T cells. IL-21 did not induce T-cell activation or proliferation, nor did it augment T-cell receptor (TCR)–induced degranulation. Treatment of patient PBMCs with IL-15 resulted in induction of perforin in association with lymphocyte proliferation and augmentation of TCR-induced degranulation. Patient CD8 T cells were more responsive to cytokine effects than the cells of healthy volunteers. We conclude that CD8 T cells of patients with HIV can be modulated by IL-21 to increase perforin expression without undergoing overt cellular activation. IL-21 could potentially be useful for its perforin-enhancing properties in anti-HIV immunotherapy.


Gut ◽  
1998 ◽  
Vol 43 (4) ◽  
pp. 499-505 ◽  
Author(s):  
A Stallmach ◽  
F Schäfer ◽  
S Hoffmann ◽  
S Weber ◽  
I Müller-Molaian ◽  
...  

Background—Immunoregulatory abnormalities of T cells might be of importance in the pathogenesis of pouchitis after ileoanal pouch anastomosis (IAP).Aims—To characterise T cell subsets, their state of activation, and production of cytokines in inflamed and non-inflamed pouches in patients with ulcerative colitis (UC) and familial adenomatous polyposis (FAP). The influence of T cell activation on mucosal transformation was also studied.Patients—Mucosal biopsy specimens were taken from 42 patients with IAP (33 with UC and nine with FAP).Methods—Mononuclear cells were isolated by standard techniques and characterised by three colour flow cytometry. Interferon γ (IFN-γ) production was studied using the ELISPOT technique.Results—In patients with UC with pouchitis there was a significant increase in the CD4:CD8 ratio, expression of activation markers on CD3+ cells, and number of IFNγ producing mononuclear cells compared with patients with UC without pouchitis (CD4:CD8 ratio 1.3 (range 0.7–2.7) versus 0.6 (0.1–1.0), p=0.012). In addition, a positive correlation between increased crypt depth and the number of CD4+ cells (r=0.57) was shown.Conclusion—The observed increase in activated mucosal CD4+ T cells and IFN-γ production might lead to mucosal destruction and crypt hyperplasia as seen in pouchitis.


Blood ◽  
2012 ◽  
Vol 120 (11) ◽  
pp. 2269-2279 ◽  
Author(s):  
Christelle Harly ◽  
Yves Guillaume ◽  
Steven Nedellec ◽  
Cassie-Marie Peigné ◽  
Hannu Mönkkönen ◽  
...  

Abstract Human peripheral Vγ9Vδ2 T cells are activated by phosphorylated metabolites (phosphoagonists [PAg]) of the mammalian mevalonate or the microbial desoxyxylulose-phosphate pathways accumulated by infected or metabolically distressed cells. The underlying mechanisms are unknown. We show that treatment of nonsusceptible target cells with antibody 20.1 against CD277, a member of the extended B7 superfamily related to butyrophilin, mimics PAg-induced Vγ9Vδ2 T-cell activation and that the Vγ9Vδ2 T-cell receptor is implicated in this effect. Vγ9Vδ2 T-cell activation can be abrogated by exposing susceptible cells (tumor and mycobacteria-infected cells, or aminobisphosphonate-treated cells with up-regulated PAg levels) to antibody 103.2 against CD277. CD277 knockdown and domain-shuffling approaches confirm the key implication of the CD277 isoform BTN3A1 in PAg sensing by Vγ9Vδ2 T cells. Fluorescence recovery after photobleaching (FRAP) experiments support a causal link between intracellular PAg accumulation, decreased BTN3A1 membrane mobility, and ensuing Vγ9Vδ2 T-cell activation. This study demonstrates a novel role played by B7-like molecules in human γδ T-cell antigenic activation and paves the way for new strategies to improve the efficiency of immunotherapies using Vγ9Vδ2 T cells.


2004 ◽  
Vol 11 (1) ◽  
pp. 195-202 ◽  
Author(s):  
Lazaros I. Sakkas ◽  
George Koussidis ◽  
Efthimios Avgerinos ◽  
John Gaughan ◽  
Chris D. Platsoucas

ABSTRACT Osteoarthritis (OA) is a heterogeneous disease which rheumatologists consider to be noninflammatory. However, recent studies suggest that, at least in certain patients, OA is an inflammatory disease and that patients often exhibit inflammatory infiltrates in the synovial membranes (SMs) of macrophages and activated T cells expressing proinflammatory cytokines. We report here that the expression of CD3ζ is significantly decreased in T cells infiltrating the SMs of patients with OA. The CD3ζ chain is involved in the T-cell signal transduction cascade, which is initiated by the engagement of the T-cell antigen receptor and which culminates in T-cell activation. Double immunofluorescence of single-cell suspensions derived from the SMs from nine patients with OA revealed significantly increased proportions of CD3ε-positive (CD3ε+) cells compared with the proportions of CD3ζ-positive (CD3ζ+) T cells (means ± standard errors of the means, 80.48% ± 3.92% and 69.02% ± 6.51%, respectively; P = 0.0096), whereas there were no differences in the proportions of these cells in peripheral blood mononuclear cells (PBMCs) from healthy donors (94.73% ± 1.39% and 93.79% ± 1.08%, respectively; not significant). The CD3ζ+ cell/CD3ε+ cell ratio was also significantly decreased for T cells from the SMs of patients with OA compared with that for T cells from the PBMCs of healthy donors (0.84 ± 0.17 and 0.99 ± 0.01, respectively; P = 0.0302). The proportions of CD3ε+ CD3ζ+ cells were lower in the SMs of patients with OA than in the PBMCs of healthy donors (65.04% ± 6.7% and 90.81% ± 1.99%, respectively; P = 0.0047). Substantial proportions (about 15%) of CD3ε+ CD3ζ-negative (CD3ζ−) and CD3ε-negative (CD3ε−) CD3ζ− cells were found in the SMs of patients with OA. Amplification of the CD3ζ and CD3δ transcripts from the SMs of patients with OA by reverse transcriptase PCR consistently exhibited stronger bands for CD3δ cDNA than for CD3ζ cDNA The CD3ζ/CD3δ transcript ratio in the SMs of patients with OA was significantly lower than that in PBMCs from healthy controls (P < 0.0001). These results were confirmed by competitive MIMIC PCR. Immunoreactivities for the CD3ζ protein were detected in the SMs of 10 of 19 patients with OA, and they were of various intensities, whereas SMs from all patients were CD3ε+ (P = 0.0023). The decreased expression of the CD3ζ transcript and protein in T cells from the SMs of patients with OA relative to that of the CD3ε transcript is suggestive of chronic T-cell stimulation and supports the concept of T-cell involvement in OA.


2009 ◽  
Vol 16 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Mark A Jensen ◽  
Rachel N Yanowitch ◽  
Anthony T Reder ◽  
David M White ◽  
Barry GW Arnason

Immunoglobulin-like transcripts (ILTs) are immunoregulatory proteins that either activate or inhibit immune responses. ILT3 is inhibitory and is expressed preferentially by antigen-presenting cells. When its extracellular domain binds to an unidentified ligand of activated T cells, the T cell is silenced. Our objective was to study the expression of ILT3 on circulating monocytes in RRMS. Freshly isolated peripheral blood mononuclear cells were analyzed by multicolored flow cytometry. The proportion of ILT3+CD14+ monocytes in blood, and ILT3 levels expressed by them, is lower in untreated multiple sclerosis in relapse than in: (1) untreated multiple sclerosis in remission (p < 0.009); (2) stable interferon β-treated relapsing—remitting multiple sclerosis (p < 0.001) and; (3) healthy controls (p < 0.009). Glatiramer acetate-stimulated CD4 + T cells, co-cultured with freshly isolated monocytes, proliferate significantly better (p = 0.0017 for multiple sclerosis; p = 0.0015 for controls) when T cell interaction with monocyte-expressed ILT3 is blocked by anti-ILT3 antibody. Interferon β is beneficial in multiple sclerosis; why so remains unclear. Interferon β-1b markedly increases ILT3 expression in vitro by monocytes from multiple sclerosis patients and controls. These findings identify a putative novel mechanism for the therapeutic benefit bestowed by Interferon β and a new target for therapeutic intervention in relapsing—remitting multiple sclerosis.


2022 ◽  
Vol 103 (1) ◽  
Author(s):  
Katarzyna Piadel ◽  
Amin Haybatollahi ◽  
Angus George Dalgleish ◽  
Peter Lawrence Smith

The pandemic caused by SARS-CoV-2 has led to the successful development of effective vaccines however the prospect of variants of SARS-CoV-2 and future coronavirus outbreaks necessitates the investigation of other vaccine strategies capable of broadening vaccine mediated T-cell responses and potentially providing cross-immunity. In this study the SARS-CoV-2 proteome was assessed for clusters of immunogenic epitopes restricted to diverse human leucocyte antigen. These regions were then assessed for their conservation amongst other coronaviruses representative of different alpha and beta coronavirus genera. Sixteen highly conserved peptides containing numerous HLA class I and II restricted epitopes were synthesized from these regions and assessed in vitro for their antigenicity against T-cells from individuals with previous SARS-CoV-2 infection. Monocyte derived dendritic cells were generated from these peripheral blood mononuclear cells (PBMC), loaded with SARS-CoV-2 peptides, and used to induce autologous CD4+ and CD8+ T cell activation. The SARS-CoV-2 peptides demonstrated antigenicity against the T-cells from individuals with previous SARS-CoV-2 infection indicating that this approach holds promise as a method to activate anti-SAR-CoV-2 T-cell responses from conserved regions of the virus which are not included in vaccines utilising the Spike protein.


Sign in / Sign up

Export Citation Format

Share Document