scholarly journals Peripheral T-Cell Reactivity to Heat Shock Protein 70 and Its Cofactor GrpE from Tropheryma whipplei Is Reduced in Patients with Classical Whipple's Disease

2017 ◽  
Vol 85 (8) ◽  
Author(s):  
Lucia Trotta ◽  
Kathleen Weigt ◽  
Katina Schinnerling ◽  
Anika Geelhaar-Karsch ◽  
Gerrit Oelkers ◽  
...  

ABSTRACT Classical Whipple's disease (CWD) is characterized by the lack of specific Th1 response toward Tropheryma whipplei in genetically predisposed individuals. The cofactor GrpE of heat shock protein 70 (Hsp70) from T. whipplei was previously identified as a B-cell antigen. We tested the capacity of Hsp70 and GrpE to elicit specific proinflammatory T-cell responses. Peripheral mononuclear cells from CWD patients and healthy donors were stimulated with T. whipplei lysate or recombinant GrpE or Hsp70 before levels of CD40L, CD69, perforin, granzyme B, CD107a, and gamma interferon (IFN-γ) were determined in T cells by flow cytometry. Upon stimulation with total bacterial lysate or recombinant GrpE or Hsp70 of T. whipplei, the proportions of activated effector CD4+ T cells, determined as CD40L+ IFN-γ+, were significantly lower in patients with CWD than in healthy controls; CD8+ T cells of untreated CWD patients revealed an enhanced activation toward unspecific stimulation and T. whipplei-specific degranulation, although CD69+ IFN-γ+ CD8+ T cells were reduced upon stimulation with T. whipplei lysate and recombinant T. whipplei-derived proteins. Hsp70 and its cofactor GrpE are immunogenic in healthy individuals, eliciting effective responses against T. whipplei to control bacterial spreading. The lack of specific T-cell responses against these T. whipplei-derived proteins may contribute to the pathogenesis of CWD.

2012 ◽  
Vol 287 (15) ◽  
pp. 12387-12394 ◽  
Author(s):  
Pawel Stocki ◽  
Xiao N. Wang ◽  
Anne M. Dickinson

Heat shock protein 70 (Hsp70) has gained a lot of attention in the past decade due to its potential immunoregulatory functions. Some of the described proinflammatory functions of Hsp70 became controversial as they were based on recombinant Hsp70 proteins specimens, which were later shown to be endotoxin-contaminated. In this study we used low endotoxin inducible Hsp70 (also known as Hsp72, HSPA1A), and we observed that after a 24-h incubation of monocyte-derived immature dendritic cells (mo-iDCs) with 20 μg/ml of low endotoxin Hsp70, their ability to stimulate allogenic T cells was reduced. Interestingly, low endotoxin Hsp70 also significantly reduced T cell responses when they were simulated with either IL-2 or phytohemagglutinin, therefore showing that Hsp70 could alter T cell responses independently from its effect on mo-iDCs. We also reported a greater response of Hsp70 treatment when activated versus nonactivated T cells were used. This effect of Hsp70 was similar for all tested populations of T cells that included CD3+, CD4+, or CD8+. Taken together, our observations strongly suggest that Hsp70 might dampen, rather than provoke, T cell-mediated inflammatory reactions in many clinical conditions where up-regulation of Hsp70 is observed.


2015 ◽  
Vol 84 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
Asami Nishimori ◽  
Ryoyo Ikebuchi ◽  
Seiko Mizorogi ◽  
...  

Johne's disease (paratuberculosis) is a chronic enteritis in cattle that is caused by intracellular infection withMycobacterium aviumsubsp.paratuberculosis. This infection is characterized by the functional exhaustion of T-cell responses toM. aviumsubsp.paratuberculosisantigens during late subclinical and clinical stages, presumably facilitating the persistence of this bacterium and the formation of clinical lesions. However, the mechanisms underlying T-cell exhaustion in Johne's disease are poorly understood. Thus, we performed expression and functional analyses of the immunoinhibitory molecules programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) and lymphocyte activation gene 3 (LAG-3)/major histocompatibility complex class II (MHC-II) inM. aviumsubsp.paratuberculosis-infected cattle during the late subclinical stage. Flow cytometric analyses revealed the upregulation of PD-1 and LAG-3 in T cells in infected animals, which suffered progressive suppression of interferon gamma (IFN-γ) responses to theM. aviumsubsp.paratuberculosisantigen. In addition, PD-L1 and MHC-II were expressed on macrophages from infected animals, consistent with PD-1 and LAG-3 pathways contributing to the suppression of IFN-γ responses during the subclinical stages ofM. aviumsubsp.paratuberculosisinfection. Furthermore, dual blockade of PD-L1 and LAG-3 enhancedM. aviumsubsp.paratuberculosis-specific IFN-γ responses in blood from infected animals, andin vitroLAG-3 blockade enhanced IFN-γ production fromM. aviumsubsp.paratuberculosis-specific CD4+and CD8+T cells. Taken together, the present data indicate thatM. aviumsubsp.paratuberculosis-specific T-cell exhaustion is in part mediated by PD-1/PD-L1 and LAG-3/MHC-II interactions and that LAG-3 is a molecular target for the control ofM. aviumsubsp.paratuberculosis-specific T-cell responses.


2016 ◽  
Vol 84 (10) ◽  
pp. 2779-2790 ◽  
Author(s):  
Tomohiro Okagawa ◽  
Satoru Konnai ◽  
James R. Deringer ◽  
Massaro W. Ueti ◽  
Glen A. Scoles ◽  
...  

The CD4+T-cell response is central for the control ofAnaplasma marginaleinfection in cattle. However, the infection induces a functional exhaustion of antigen-specific CD4+T cells in cattle immunized withA. marginaleouter membrane proteins or purified outer membranes (OMs), which presumably facilitates the persistence of this rickettsia. In the present study, we hypothesize that T-cell exhaustion following infection is induced by the upregulation of immunoinhibitory receptors on T cells, such as programmed death 1 (PD-1) and lymphocyte activation gene 3 (LAG-3). OM-specific T-cell responses and the kinetics of PD-1-positive (PD-1+) LAG-3+exhausted T cells were monitored inA. marginale-challenged cattle previously immunized with OMs. Consistent with data from previous studies, OM-specific proliferation of peripheral blood mononuclear cells (PBMCs) and interferon gamma (IFN-γ) production were significantly suppressed in challenged animals by 5 weeks postinfection (wpi). In addition, bacteremia and anemia also peaked in these animals at 5 wpi. Flow cytometric analysis revealed that the percentage of PD-1+LAG-3+T cells in the CD4+, CD8+, and γδ T-cell populations gradually increased and also peaked at 5 wpi. A large increase in the percentage of LAG-3+γδ T cells was also observed. Importantly,in vitro, the combined blockade of the PD-1 and LAG-3 pathways partially restored OM-specific PBMC proliferation and IFN-γ production at 5 wpi. Taken together, these results indicate that coexpression of PD-1 and LAG-3 on T cells contributes to the rapid exhaustion ofA. marginale-specific T cells following infection and that these immunoinhibitory receptors regulate T-cell responses during bovine anaplasmosis.


2013 ◽  
Vol 21 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Tetsu Mukai ◽  
Yumiko Tsukamoto ◽  
Yumi Maeda ◽  
Toshiki Tamura ◽  
Masahiko Makino

ABSTRACTFor the purpose of obtainingMycobacterium bovisbacillus Calmette-Guérin (BCG) capable of activating human naive T cells, urease-deficient BCG expressing a fusion protein composed ofMycobacterium tuberculosis-derived major membrane protein II (MMP-II) and heat shock protein 70 (HSP70) of BCG (BCG-DHTM) was produced. BCG-DHTM secreted the HSP70-MMP-II fusion protein and effectively activated human monocyte-derived dendritic cells (DCs) by inducing phenotypic changes and enhanced cytokine production. BCG-DHTM-infected DCs activated naive T cells of both CD4 and naive CD8 subsets, in an antigen (Ag)-dependent manner. The T cell activation induced by BCG-DHTM was inhibited by the pretreatment of DCs with chloroquine. The naive CD8+T cell activation was mediated by the transporter associated with antigen presentation (TAP) and the proteosome-dependent cytosolic cross-priming pathway. Memory CD8+T cells and perforin-producing effector CD8+T cells were efficiently produced from the naive T cell population by BCG-DHTM stimulation. Single primary infection with BCG-DHTM in C57BL/6 mice efficiently produced T cells responsive toin vitrosecondary stimulation with HSP70, MMP-II, andM. tuberculosis-derived cytosolic protein and inhibited the multiplication of subsequently aerosol-challengedM. tuberculosismore efficiently than did vector control BCG. These results indicate that the introduction of MMP-II and HSP70 into urease-deficient BCG may be useful for improving BCG for control of tuberculosis.


2011 ◽  
Vol 70 (Suppl 2) ◽  
pp. A44-A45 ◽  
Author(s):  
E. Koffeman ◽  
E. Elst ◽  
F. van Wijk ◽  
B. Prakken ◽  
A. van Royen-Kerkhof

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Pritesh Desai ◽  
Vikas Tahiliani ◽  
Georges Abboud ◽  
Jessica Stanfield ◽  
Shahram Salek-Ardakani

ABSTRACTRespiratory infection with vaccinia virus (VacV) elicits robust CD8+T cell responses that play an important role in host resistance. In the lung, VacV encounters multiple tissue-resident antigen-presenting cell (APC) populations, but which cell plays a dominant role in priming of virus-specific CD8+effector T cell responses remains poorly defined. We used Batf3−/−mice to investigate the impact of CD103+and CD8α+dendritic cell (DC) deficiency on anti-VacV CD8+T cell responses. We found that Batf3−/−mice were more susceptible to VacV infection, exhibiting profound weight loss, which correlated with impaired accumulation of gamma interferon (IFN-γ)-producing CD8+T cells in the lungs. This was largely due to defective priming since early in the response, antigen-specific CD8+T cells in the draining lymph nodes of Batf3−/−mice expressed significantly reduced levels of Ki67, CD25, and T-bet. These results underscore a specific role for Batf3-dependent DCs in regulating priming and expansion of effector CD8+T cells necessary for host resistance against acute respiratory VacV infection.IMPORTANCEDuring respiratory infection with vaccinia virus (VacV), a member ofPoxviridaefamily, CD8+T cells play important role in resolving the primary infection. Effector CD8+T cells clear the virus by accumulating in the infected lungs in large numbers and secreting molecules such as IFN-γ that kill virally infected cells. However, precise cell types that regulate the generation of effector CD8+T cells in the lungs are not well defined. Dendritic cells (DCs) are a heterogeneous population of immune cells that are recognized as key initiators and regulators of T-cell-mediated immunity. In this study, we reveal that a specific subset of DCs that are dependent on the transcription factor Batf3 for their development regulate the magnitude of CD8+T cell effector responses in the lungs, thereby providing protection during pulmonary VacV infection.


2016 ◽  
Vol 84 (9) ◽  
pp. 2627-2638 ◽  
Author(s):  
Charles S. Rosenberg ◽  
Weibo Zhang ◽  
Juan M. Bustamante ◽  
Rick L. Tarleton

Trypanosoma cruziinfection drives the expansion of remarkably focused CD8+T cell responses targeting epitopes encoded by varianttrans-sialidase (TS) genes. Infection of C57BL/6 mice withT. cruziresults in up to 40% of all CD8+T cells committed to recognition of the dominant TSKB20 and subdominant TSKB18 TS epitopes. However, despite this enormous response, these mice fail to clearT. cruziinfection and subsequently develop chronic disease. One possible reason for the failure to cureT. cruziinfection is that immunodomination by these TS-specific T cells may interfere with alternative CD8+T cell responses more capable of complete parasite elimination. To address this possibility, we created transgenic mice that are centrally tolerant to these immunodominant epitopes. Mice expressing TSKB20, TSKB18, or both epitopes controlledT. cruziinfection and developed effector CD8+T cells that maintained an activated phenotype. Memory CD8+T cells from drug-cured TSKB-transgenic mice rapidly responded to secondaryT. cruziinfection. In the absence of the response to TSKB20 and TSKB18, immunodominance did not shift to other known subdominant epitopes despite the capacity of these mice to expand epitope-specific T cells specific for the model antigen ovalbumin expressed by engineered parasites. Thus, CD8+T cell responses tightly and robustly focused on a few epitopes within variant TS antigens appear to neither contribute to, nor detract from, the ability to controlT. cruziinfection. These data also indicate that the relative position of an epitope within a CD8+immunodominance hierarchy does not predict its importance in pathogen control.


1999 ◽  
Vol 70 (1-2) ◽  
pp. 105-115 ◽  
Author(s):  
A.P Koets ◽  
V.P.M.G Rutten ◽  
A Hoek ◽  
D Bakker ◽  
F van Zijderveld ◽  
...  

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 623-623
Author(s):  
Andreas Heitger ◽  
Birgit Juergens ◽  
Ursula Hainz ◽  
Dietmar Fuchs

Abstract An enhanced tryptophan metabolism mediated by the enzymatic activity of indoleamine 2,3 dioxygenase (IDO) has recently been demonstrated to profoundly affect T cell responses. By the present study we explored whether human dendritic cells (DCs) displaying high IDO expression and activity, down-regulate allogeneic T cell responses. A comparison of lipopolysaccaride (LPS), interferon-γ (IFN-γ), and CD40L as DC maturation agents showed that most abundant IDO expression and activity in DCs was observed when immature DCs were exposed to a combination of LPS and IFN-γ for 48 hours. This time period of maturation was associated with the development of a mature DC phenotype. In contrast, semi-mature DCs, i.e. DCs matured for 4 hours only, were IDO negative. In co-cultures with allogeneic T cells both types of DCs began to metabolize tryptophan, as determined by decreasing concentrations of tryptophan and increasing concentrations of kynurenines in cell culture supernatants, but mature IDO positive DCs did so at a faster rate (complete consumption of tryptophan within 16 hours of co-culture) than semi-mature DCs. A comparison of the allo-stimulatory capacity of semi-mature IDO negative DCs and mature IDO positive DCs showed that at a high DC/T cell ratio (1:1) IDO positive DCs had a significantly reduced capacity to stimulate allogeneic T cells (median 63% reduction, n=5). The reduction of the allogeneic T cell response induced by IDO positive DCs was reversed upon the addition of the IDO inhibitor methylhydantoin-tryptophan to the co-cultures, suggesting an IDO dependent mechanism. Furthermore, allogeneic T cells exposed to IDO positive DCs had an increased rate of apoptosis in the activated cell fraction and after 8 days of co-culture contained a cell fraction (~30%) displaying a CD4+CD25+highFOXP3+ phenotype. These latter cells, when enriched by fluorescent activated cell sorting (FACS), were able to suppress the proliferative response of naive T cells to anti-CD3 mediated stimulation, which indicates the generation of a regulatory T cell population by IDO positive DCs. Together, these findings suggest that the amount of IDO expression and activity by DCs is one feature to govern the type of response of stimulated T cells. Human DCs can be induced to display high levels of IDO expression and activity and, thereby, acquire the ability to effectivley modulate allogeneic T cell responses towards tolerance by eliminating allo-reactive T cells through apoptosis and augmentation of their regulatory rather than their effector potential. Our current approaches address whether this property can be employed to use DCs for the generation of allo-antigen specific tolerance in the setting of hematopoietic cell transplantation.


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