scholarly journals Expression of JAK3 Sensitive Na+ Coupled Glucose Carrier SGLT1 in Activated Cytotoxic T Lymphocytes

2016 ◽  
Vol 39 (3) ◽  
pp. 1209-1228 ◽  
Author(s):  
Shefalee K. Bhavsar ◽  
Yogesh Singh ◽  
Piyush Sharma ◽  
Vishal Khairnar ◽  
Zohreh Hosseinzadeh ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cell Membrane ◽  
Glucose Uptake ◽  
Xenopus Oocytes ◽  
Cytotoxic T Cells ◽  
Brefeldin A ◽  
Protein Abundance ◽  
Jurkat T Cells ◽  
Glucose Carrier

Background: Similar to tumor cells, activated T-lymphocytes generate ATP mainly by glycolytic degradation of glucose. Lymphocyte glucose uptake involves non-concentrative glucose carriers of the GLUT family. In contrast to GLUT isoforms, Na+-coupled glucose-carrier SGLT1 accumulates glucose against glucose gradients and is effective at low extracellular glucose concentrations. The present study explored expression and regulation of SGLT1 in activated murine splenic cytotoxic T cells (CTLs) and human Jurkat T cells. Methods: FACS analysis, immunofluorescence, confocal microscopy, chemiluminescence and Western blotting were employed to estimate SGLT1 expression, function and regulation in lymphocytes, as well as dual electrode voltage clamp in SGLT1 ± JAK3 expressing Xenopus oocytes to quantify the effect of janus kinase3 (JAK3) on SGLT1 function. Results: SGLT1 is expressed in murine CTLs and also in human Jurkat T cells. 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose uptake was significantly decreased by SGLT1-blocker phloridzin (0.2 mM) and by pharmacological inhibition of JAK3 with WHI-P131 (156 µM), WHI-P154 (11.2 µM) and JAK3 inhibitor VI (0.5 µM). Electrogenic glucose transport (Iglucose) in Xenopus oocytes expressing human SGLT1 was increased by additional expression of human wild type JAK3, active A568VJAK3 but not inactive K851AJAK3. Coexpression of JAK3 enhanced the maximal transport rate without significantly modifying affinity of the carrier. Iglucose in SGLT1+JAK3 expressing oocytes was significantly decreased by WHI-P154 (11.2 µM). JAK3 increased the SGLT1 protein abundance in the cell membrane. Inhibition of carrier insertion by brefeldin A (5 µM) in SGLT1+JAK3 expressing oocytes resulted in a decline of Iglucose, which was similar in presence and absence of JAK3. Conclusions: SGLT1 is expressed in murine cytotoxic T cells and human Jurkat T cells and significantly contributes to glucose uptake in those cells post activation. JAK3 up-regulates SGLT1 activity by increasing the carrier protein abundance in the cell membrane, an effect enforcing cellular glucose uptake into activated lymphocytes and thus contributing to the immune response.

scholarly journals Tumor-Specific CD4+T Lymphocytes from Cancer Patients Are Required for Optimal Induction of Cytotoxic T Cells Against the Autologous Tumor

2000 ◽  
Vol 164 (7) ◽  
pp. 3902-3912 ◽  
Author(s):  
Constantin N. Baxevanis ◽  
Ioannis F. Voutsas ◽  
Ourania E. Tsitsilonis ◽  
Angelos D. Gritzapis ◽  
Roula Sotiriadou ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cancer Patients ◽  
Cytotoxic T Cells ◽  
Autologous Tumor

scholarly journals PIWIL4 Maintains HIV-1 Latency by Enforcing Epigenetically Suppressive Modifications on the 5′ Long Terminal Repeat

2020 ◽  
Vol 94 (10) ◽  
Author(s):  
Zhangping He ◽  
Shuliang Jing ◽  
Tao Yang ◽  
Jingliang Chen ◽  
Feng Huang ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
P Element ◽  
Latent Reservoir ◽  
Jurkat T Cells ◽  
Latently Infected ◽  
Novel Strategy ◽  
Hiv 1

ABSTRACT Although substantial progress has been made in depicting the molecular pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection, the comprehensive mechanism of HIV-1 latency and the most promising therapeutic strategies to effectively reactivate the HIV-1 latent reservoir to achieve a functional cure for AIDS remain to be systematically illuminated. Here, we demonstrated that piwi (P element-induced Wimpy)-like RNA-mediated gene silencing 4 (PIWIL4) played an important role in suppressing HIV-1 transcription and contributed to the latency state in HIV-1-infected cells through its recruitment of various suppressive factors, including heterochromatin protein 1α/β/γ, SETDB1, and HDAC4. The knockdown of PIWIL4 enhanced HIV-1 transcription and reversed HIV-1 latency in both HIV-1 latently infected Jurkat T cells and primary CD4+ T lymphocytes and resting CD4+ T lymphocytes from HIV-1-infected individuals on suppressive combined antiretroviral therapy (cART). Furthermore, in the absence of PIWIL4, HIV-1 latently infected Jurkat T cells were more sensitive to reactivation with vorinostat (suberoylanilide hydroxamic acid, or SAHA), JQ1, or prostratin. These findings indicated that PIWIL4 promotes HIV-1 latency by imposing repressive marks at the HIV-1 5′ long terminal repeat. Thus, the manipulation of PIWIL4 could be a novel strategy for developing promising latency-reversing agents (LRAs). IMPORTANCE HIV-1 latency is systematically modulated by host factors and viral proteins. During this process, the suppression of HIV-1 transcription plays an essential role in promoting HIV-1 latency. In this study, we found that PIWIL4 repressed HIV-1 promoter activity and maintained HIV-1 latency. In particular, we report that PIWIL4 can regulate gene expression through its association with the suppressive activity of HDAC4. Therefore, we have identified a new function for PIWIL4: it is not only a suppressor of endogenous retrotransposons but also plays an important role in inhibiting transcription and leading to latent infection of HIV-1, a well-known exogenous retrovirus. Our results also indicate a novel therapeutic target to reactivate the HIV-1 latent reservoir.

scholarly journals Induction of Phosphodiesterases 3B, 4A4, 4D1, 4D2, and 4D3 in Jurkat T-cells and in Human Peripheral Blood T-lymphocytes by 8-Bromo-cAMP and Gs-coupled Receptor Agonists

1998 ◽  
Vol 273 (32) ◽  
pp. 20575-20588 ◽  
Author(s):  
Joachim Seybold ◽  
Robert Newton ◽  
Lyndon Wright ◽  
Paul A. Finney ◽  
Norbert Suttorp ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Jurkat T Cells ◽  
Receptor Agonists

scholarly journals Two distinct mechanisms regulate the in vivo generation of cytotoxic T cells.

1982 ◽  
Vol 156 (3) ◽  
pp. 918-923 ◽  
Author(s):  
M S Sy ◽  
S H Lee ◽  
M Tsurufuji ◽  
K L Rock ◽  
B Benacerraf ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Concanavalin A ◽  
Cytotoxic T Cells ◽  
Cytolytic T Lymphocytes ◽  
Spleen Cells ◽  
Suppressor T Cells ◽  
Con A

Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.

scholarly journals HLA B37 determines an influenza A virus nucleoprotein epitope recognized by cytotoxic T lymphocytes.

1986 ◽  
Vol 164 (5) ◽  
pp. 1397-1406 ◽  
Author(s):  
A J McMichael ◽  
F M Gotch ◽  
J Rothbard
Keyword(s):  
Amino Acids ◽  
T Cells ◽  
T Lymphocytes ◽  
Influenza A Virus ◽  
Cytotoxic T Lymphocytes ◽  
Synthetic Peptide ◽  
Influenza A ◽  
Cytotoxic T Cells ◽  
Human Influenza ◽  
Infected Cells

Human influenza A virus-specific, cytotoxic T cells have been shown previously to recognize the virus nucleoprotein on infected cells. CTL preparations from four HLA B37-positive donors were shown to recognize a synthetic peptide that corresponded to amino acids 335-349 of the nucleoprotein sequence. Influenza-specific CTL from 10 donors of other HLA types failed to recognize this epitope. CD8+ CTL lines were derived from lymphocytes of two HLA B37-positive donors and used to show that the peptide was represented on virus-infected cells and to determine the probable boundaries of the epitope.

scholarly journals Target-Cell Contact Activates a Highly Selective Capacitative Calcium Entry Pathway in Cytotoxic T Lymphocytes

2000 ◽  
Vol 148 (3) ◽  
pp. 603-614 ◽  
Author(s):  
Adam Zweifach
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Lymphocytes ◽  
T Cell Receptor ◽  
Target Cell ◽  
Calcium Influx ◽  
Cytotoxic T Cells ◽  
Cell Receptor ◽  
Cell Contact ◽  
Crac Channels

Calcium influx is critical for T cell activation. Evidence has been presented that T cell receptor–stimulated calcium influx in helper T lymphocytes occurs via channels activated as a consequence of depletion of intracellular calcium stores, a mechanism known as capacitative Ca2+ entry (CCE). However, two key questions have not been addressed. First, the mechanism of calcium influx in cytotoxic T cells has not been examined. While the T cell receptor–mediated early signals in helper and cytotoxic T cells are similar, the physiology of the cells is strikingly different, raising the possibility that the mechanism of calcium influx is also different. Second, contact of T cells with antigen-presenting cells or targets involves a host of intercellular interactions in addition to those between antigen–MHC and the T cell receptor. The possibility that calcium influx pathways in addition to those activated via the T cell receptor may be activated by contact with relevant cells has not been addressed. We have used imaging techniques to show that target-cell–stimulated calcium influx in CTLs occurs primarily through CCE. We investigated the permeability of the CTL influx pathway for divalent cations, and compared it to the permeability of CCE in Jurkat human leukemic T cells. CCE in CTLs shows a similar ability to discriminate between calcium, barium, and strontium as CCE in Jurkat human leukemic T lymphocytes, where CCE is likely to mediated by Ca2+ release–activated Ca2+ current (CRAC) channels, suggesting that CRAC channels also underlie CCE in CTLs. These results are the first determination of the mechanism of calcium influx in cytotoxic T cells and the first demonstration that cell contact–mediated calcium signals in T cells occur via depletion-activated channels.

scholarly journals Elucidating the Functional Roles of Helper and Cytotoxic T Cells in the Cell-Mediated Immune Responses of Olive Flounder (Paralichthys olivaceus)

2021 ◽  
Vol 22 (2) ◽  
pp. 847
Author(s):  
Jae Wook Jung ◽  
Ae Rin Lee ◽  
Jaesung Kim ◽  
Young Rim Kim ◽  
Jassy Mary S. Lazarte ◽  
...  
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Immune Responses ◽  
Cytotoxic T Cells ◽  
Paralichthys Olivaceus ◽  
Olive Flounder ◽  
Control Group ◽  
Adaptive Immune ◽  
Cd8 T Lymphocytes ◽  
Olive Flounder Paralichthys Olivaceus

In higher vertebrates, helper and cytotoxic T cells, referred to as CD4 and CD8 T lymphocytes, respectively, are mainly associated with adaptive immunity. The adaptive immune system in teleosts involves T cells equivalent to those found in mammals. We previously generated monoclonal antibodies (mAbs) against olive flounder (Paralichthys olivaceus) CD4 T cells, CD4-1 and CD4-2, and used these to describe the olive flounder’s CD4 Tcell response during a viral infection. In the present study, we successfully produced mAbs against CD8 T lymphocytes and their specificities were confirmed using immuno-blotting, immunofluorescence staining, flow cytometry analysis andreverse transcription polymerase chain reaction (RT-PCR). The results showed that these mAbs are specific for CD8 T lymphocytes. We also investigated variations in CD4 and CD8 T cells populations, and analyzed the expression of immune-related genes expressed by these cells in fish infected with nervous necrosis virus or immunized with thymus dependent and independent antigens. We found that both CD4 and CD8 T lymphocyte populations significantly increased in these fish and Th1-related genes were up-regulated compared to the control group. Collectively, these findings suggest that the CD4 and CD8 T lymphocytes in olive flounder are similar to the helper and cytotoxic T cells found in mammals, and Th1 and cytotoxic immune responses are primarily involved in the early adaptive immune response against extracellular antigens.

Upregulation of the large conductance voltage- and Ca2+-activated K+ channels by Janus kinase 2

2014 ◽  
Vol 306 (11) ◽  
pp. C1041-C1049 ◽  
Author(s):  
Zohreh Hosseinzadeh ◽  
Ahmad Almilaji ◽  
Sabina Honisch ◽  
Tatsiana Pakladok ◽  
GuoXing Liu ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Brefeldin A ◽  
Bk Channels ◽  
Bk Channel ◽  
Janus Kinase ◽  
Protein Abundance ◽  
Janus Kinase 2 ◽  
Channel Protein ◽  
Jak2 Inhibitor ◽  
Whole Cell Patch Clamp

The iberiotoxin-sensitive large conductance voltage- and Ca2+-activated potassium (BK) channels (maxi-K+-channels) hyperpolarize the cell membrane thus supporting Ca2+ entry through Ca2+-release activated Ca2+ channels. Janus kinase-2 (JAK2) has been identified as novel regulator of ion transport. To explore whether JAK2 participates in the regulation of BK channels, cRNA encoding Ca2+-insensitive BK channels (BKM513I+Δ899–903) was injected into Xenopus oocytes with or without cRNA encoding wild-type JAK2, gain-of-function V617FJAK2, or inactive K882EJAK2. K+ conductance was determined by dual electrode voltage clamp and BK-channel protein abundance by confocal microscopy. In A204 alveolar rhabdomyosarcoma cells, iberiotoxin-sensitive K+ current was determined utilizing whole cell patch clamp. A204 cells were further transfected with JAK2 and BK-channel transcript, and protein abundance was quantified by RT-PCR and Western blotting, respectively. As a result, the K+ current in BKM513I+Δ899–903-expressing oocytes was significantly increased following coexpression of JAK2 or V617FJAK2 but not K882EJAK2. Coexpression of the BK channel with V617FJAK2 but not K882EJAK2 enhanced BK-channel protein abundance in the oocyte cell membrane. Exposure of BK-channel and V617FJAK2-expressing oocytes to the JAK2 inhibitor AG490 (40 μM) significantly decreased K+ current. Inhibition of channel insertion by brefeldin A (5 μM) decreased the K+ current to a similar extent in oocytes expressing the BK channel alone and in oocytes expressing the BK channel and V617FJAK2. The iberiotoxin (50 nM)-sensitive K+ current in rhabdomyosarcoma cells was significantly decreased by AG490 pretreatment (40 μM, 12 h). Moreover, overexpression of JAK2 in A204 cells significantly enhanced BK channel mRNA and protein abundance. In conclusion, JAK2 upregulates BK channels by increasing channel protein abundance in the cell membrane.

scholarly journals Low dose radiosensitivity of alloimmune cytotoxic T cells.

1982 ◽  
Vol 155 (6) ◽  
pp. 1858-1863 ◽  
Author(s):  
C Spellman ◽  
R E Anderson
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Cell Cultures ◽  
Low Dose ◽  
Cytotoxic T Cells ◽  
X Rays ◽  
Effector Cells ◽  
Chromium Release

Low dose radiosensitivity of in vitro generated alloimmune murine cytotoxic T lymphocytes (CTL) was studied. It appears that a subset of CTL exists that can be killed with 10-25 rad of x rays. These radiosensitive CTL are Lyt-1,2+ T lymphocytes. Analyses of cytotoxicity by chromium release assays indicate that the radiosensitive CTL are present in responder spleen cell cultures from all strains of mice tested. The generation of these effector cells is most pronounced in animals of the C57BL background. The mechanism of low dose radiosensitivity appears to be interphase death.

scholarly journals Capsid-Specific Cytotoxic T Lymphocytes Recognize Three Distinct H-2Db-Restricted Regions of the BeAn Strain of Theiler's Virus and Exhibit Different Cytokine Profiles

2002 ◽  
Vol 76 (7) ◽  
pp. 3125-3134 ◽  
Author(s):  
Michael A. Lyman ◽  
Hee-Gu Lee ◽  
Bong Su Kang ◽  
Hee-Kap Kang ◽  
Byung S. Kim
Keyword(s):  
T Cells ◽  
T Lymphocytes ◽  
Cytotoxic T Lymphocytes ◽  
Demyelinating Disease ◽  
Cytotoxic T Cells ◽  
Genetic Locus ◽  
Target Cells ◽  
Cytokine Profiles ◽  
Leader Protein ◽  
And Function

ABSTRACT The role of virus-specific cytotoxic T lymphocytes (CTL) in Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease, a viral model for multiple sclerosis, is not yet clear. To investigate the specificity and function of CTL generated in response to TMEV infection, we generated a panel of overlapping 20-mer peptides encompassing the entire capsid and leader protein region of the BeAn strain of TMEV. Binding of these peptides to H-2Kb and H-2Db class I molecules of resistant mice was assessed using RMA-S cells. Several peptides displayed significant binding to H-2Kb, H-2Db, or both. However, infiltrating cytotoxic T cells in the central nervous system of virus-infected mice preferentially lysed target cells pulsed with VP2111-130/121-140 or VP2121-130, a previously defined CTL epitope shared by the DA strain of TMEV and other closely related cardioviruses. In addition, at a high effector-to-target cell ratio, two additional peptides (VP2161-180 and VP3101-120) sensitized target cells for cytolysis by infiltrating T cells or splenic T cells from virus-infected mice. The minimal epitopes within these peptides were defined as VP2165-173 and VP3110-120. Based on cytokine profiles, CTL specific for these subdominant epitopes are Tc2, in contrast to CTL for the immunodominant epitope, which are of the Tc1 type. Interestingly, CTL function towards both of these subdominant epitopes is restricted by the H-2D molecule, despite the fact that these epitopes bind both H-2K and H-2D molecules. This skewing toward an H-2Db-restricted response may confer resistance to TMEV-induced demyelinating disease, which is known to be associated with the H-2D genetic locus.

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