scholarly journals INTRACELLULAR MECHANISMS OF TUMOR CELL IMMUNORESISTANCE

2020 ◽  
Author(s):  
Justyna Hermanowicz ◽  
Beata Sieklucka ◽  
Krzysztof Nosek ◽  
Dariusz Pawlak
Keyword(s):  
Immune Response ◽  
T Lymphocytes ◽  
Tumor Cell ◽  
Cancer Cells ◽  
T Lymphocyte ◽  
Intracellular Signaling ◽  
Immune Checkpoints ◽  
Tumor Control ◽  
Lymphocyte Function ◽  
Intracellular Signaling Pathways

One of the main mechanisms for avoiding immune response by cancer cells is by inducing an immunosuppressive environment in the tumor, following the activation of immune checkpoints i.e. PD-1 or CTLA-4  receptor inhibitors on T lymphocytes. Inhibiting the interaction between PD-1 or CTLA-4 and their ligands (PD-L1, CD80, and CD85) leads to unblocking T-lymphocyte function, and thus destroying cancer cells. Certain intracellular signaling pathways are also involved in the development of tumor cell immunoresistance. Blocking the activation of immunosuppressive pathways  may increase immunological anti-tumor control

scholarly journals Immune Checkpoint Receptors Tim-3 and PD-1 Regulate Monocyte and T Lymphocyte Function in Septic Patients

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Qi Xia ◽  
Li Wei ◽  
Yuntao Zhang ◽  
Jifang Sheng ◽  
Wei Wu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Immune Response ◽  
T Lymphocytes ◽  
Signaling Pathway ◽  
T Lymphocyte ◽  
Receptor Blockade ◽  
Lymphocyte Function ◽  
Significant Elevation ◽  
Programmed Cell Death 1 ◽  
Checkpoint Receptors

We aim to investigate the effects of Tim-3 and programmed cell death-1 (PD-1) on the monocytes and T lymphocytes in septic patients. Expression of Tim-3 and PD-1 on the CD3, CD4, and CD8 lymphocytes and monocytes was determined using flow cytometry. CBA technique was utilized to determine the expression of cytokines in the lymphocyte supernatant in addition to the IL-10 and TNF-αpositivity in monocytes in the presence of Tim-3 and/or PD-1 receptor blockade. Compared with the normal control, significant elevation was observed in the expression of PD-1 on CD3 (P=0.004), CD4, and CD8 monocytes. Blockade of the Tim-3 signaling pathway contributed to the significant elevation of IL-10 and TNF-αin the supernatant of T lymphocytes in the septic patients, while the PD-1 signaling pathway blockade only triggered the obvious elevation of TNF-αin the T lymphocytes. Blockade of Tim-3 and PD-1 induced the positivity of IL-10- and TNF-α-expressing cells in the peripheral monocytes. Significant changes were noticed in the Tim-3 and PD-1 in the T lymphocytes and monocytes. Blockade of Tim-3 and PD-1 contributed to the function of lymphocytes and monocytes. In the septic process, Tim-3 and PD-1 played crucial roles in the immune response of T lymphocytes and monocytes.

scholarly journals Control of T lymphocyte fate decisions by PI3K signaling

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1171
Author(s):  
Benjamin Murter ◽  
Lawrence P. Kane
Keyword(s):  
Signaling Pathways ◽  
T Lymphocyte ◽  
Intracellular Signaling ◽  
B Lymphocyte ◽  
Lymphocyte Function ◽  
Antigen Receptors ◽  
Lipid Kinase ◽  
Cellular Processes ◽  
Intracellular Signaling Pathways ◽  
B Lymphocyte Development

Virtually all aspects of T and B lymphocyte development, homeostasis, activation, and effector function are impacted by the interaction of their clonally distributed antigen receptors with antigens encountered in their respective environments. Antigen receptors mediate their effects by modulating intracellular signaling pathways that ultimately impinge on the cytoskeleton, bioenergetic pathways, transcription, and translation. Although these signaling pathways are rather well described at this point, especially those steps that are most receptor-proximal, how such pathways contribute to more quantitative aspects of lymphocyte function is still being elucidated. One of the signaling pathways that appears to be involved in this “tuning” process is controlled by the lipid kinase PI3K. Here we review recent key findings regarding both the triggering/enhancement of PI3K signals (via BCAP and ICOS) as well as their regulation (via PIK3IP1 and PHLPP) and how these signals integrate and determine cellular processes. Lymphocytes display tremendous functional plasticity, adjusting their metabolism and gene expression programs to specific conditions depending on their tissue of residence and the nature of the infectious threat to which they are responding. We give an overview of recent findings that have contributed to this model, with a focus on T cells, including what has been learned from patients with gain-of-function mutations in PI3K as well as lessons from cancer immunotherapy approaches.

scholarly journals Differential CD4+ T-Lymphocyte Apoptosis and Bystander T-Cell Activation in Rhesus Macaques and Sooty Mangabeys during Acute Simian Immunodeficiency Virus Infection

2008 ◽  
Vol 83 (2) ◽  
pp. 572-583 ◽  
Author(s):  
Mareike Meythaler ◽  
Amanda Martinot ◽  
Zichun Wang ◽  
Sarah Pryputniewicz ◽  
Melissa Kasheta ◽  
...  
Keyword(s):  
Immune Response ◽  
T Lymphocytes ◽  
T Lymphocyte ◽  
Immune Activation ◽  
Rhesus Macaques ◽  
Lymphocyte Apoptosis ◽  
Immunodeficiency Virus ◽  
Sooty Mangabeys ◽  
Siv Infection ◽  
Species Specific

ABSTRACT In contrast to pathogenic lentiviral infections, chronic simian immunodeficiency virus (SIV) infection in its natural host is characterized by a lack of increased immune activation and apoptosis. To determine whether these differences are species specific and predicted by the early host response to SIV in primary infection, we longitudinally examined T-lymphocyte apoptosis, immune activation, and the SIV-specific cellular immune response in experimentally infected rhesus macaques (RM) and sooty mangabeys (SM) with controlled or uncontrolled SIV infection. SIVsmE041, a primary SIVsm isolate, reproduced set-point viremia levels of natural SIV infection in SM but was controlled in RM, while SIVmac239 replicated to high levels in RM. Following SIV infection, increased CD8+ T-lymphocyte apoptosis, temporally coinciding with onset of SIV-specific cellular immunity, and elevated plasma Th1 cytokine and gamma interferon-induced chemokine levels were common to both SM and RM. Different from SM, SIV-infected RM showed a significantly higher frequency of peripheral blood activated CD8+ T lymphocytes despite comparable magnitude of the SIV-specific gamma interferon enzyme-linked immunospot response. Furthermore, an increase in CD4+ and CD4−CD8− T-lymphocyte apoptosis and plasma tumor necrosis factor-related apoptosis-inducing ligand were observed only in RM and occurred in both controlled SIVsmE041 and uncontrolled SIVmac239 infection. These data suggest that the “excess” activated T lymphocytes in RM soon after SIV infection are predominantly of non-virus-specific bystander origin. Thus, species-specific differences in the early innate immune response appear to be an important factor contributing to differential immune activation in natural and nonnatural hosts of SIV infection.

scholarly journals A Combination of Glutaminase Inhibitor 968 and PD-L1 Blockade Boosts the Immune Response against Ovarian Cancer

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1749
Author(s):  
Jing-Jing Wang ◽  
Michelle Kwan-Yee Siu ◽  
Yu-Xin Jiang ◽  
Thomas Ho-Yin Leung ◽  
David Wai Chan ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Immune Response ◽  
T Cells ◽  
Cancer Cells ◽  
Cd8 T Cells ◽  
Granzyme B ◽  
Combined Treatment ◽  
In Vivo Studies ◽  
Immune Checkpoints ◽  
Ovarian Cancer Cells

Programmed cell death 1 ligand (PD-L1) blockade has been used therapeutically in the treatment of ovarian cancer, and potential combination treatment approaches are under investigation to improve the treatment response rate. The increased dependence on glutamine is widely observed in various type of tumors, including ovarian cancer. Kidney-type glutaminase (GLS), as one of the isotypes of glutaminase, is found to promote tumorigenesis. Here, we have demonstrated that the combined treatment with GLS inhibitor 968 and PD-L1 blockade enhances the immune response against ovarian cancer. Survival analysis using the Kaplan–Meier plotter dataset from ovarian cancer patients revealed that the expression level of GLS predicts poor survival and correlates with the immunosuppressive microenvironment of ovarian cancer. 968 inhibits the proliferation of ovarian cancer cells and enhances granzyme B secretion by CD8+ T cells as detected by XTT assay and flow cytometry, respectively. Furthermore, 968 enhances the apoptosis-inducing ability of CD8+ T cells toward cancer cells and improves the treatment effect of anti-PD-L1 in treating ovarian cancer as assessed by Annexin V apoptosis assay. In vivo studies demonstrated the prolonged overall survival upon combined treatment of 968 with anti-PD-L1 accompanied by increased granzyme B secretion by CD4+ and CD8+ T cells isolated from ovarian tumor xenografts. Additionally, 968 increases the infiltration of CD3+ T cells into tumors, possibly through enhancing the secretion of CXCL10 and CXCL11 by tumor cells. In conclusion, our findings provide a novel insight into ovarian cancer cells influence the immune system in the tumor microenvironment and highlight the potential clinical implication of combination of immune checkpoints with GLS inhibitor 968 in treating ovarian cancer.

scholarly journals Carbohydrate supplementation and exercise-induced changes in T-lymphocyte function

2003 ◽  
Vol 95 (3) ◽  
pp. 1216-1223 ◽  
Author(s):  
Katherine J. Green ◽  
Susan J. Croaker ◽  
David G. Rowbottom
Keyword(s):  
Cell Death ◽  
T Lymphocytes ◽  
T Lymphocyte ◽  
Immune Cell ◽  
Ventilatory Threshold ◽  
Random Order ◽  
Cortisol Response ◽  
Lymphocyte Function ◽  
Lymphocyte Responses ◽  
Response To Exercise

Carbohydrate (CHO) ingestion during exercise has been shown to reduce perturbations in immune cell numbers and function, possibly through a reduction in the cortisol response to exercise. We have previously observed that exercise decreases T-lymphocyte responses to mitogen via an increase in cell death of both CD4 and CD8 T lymphocytes (Green KJ and Rowbottom DG. J Appl Physiol. 95: 57-63, 2003). This study tested the hypothesis that CHO ingestion rather than placebo (Pl) would result in an attenuation of the cortisol response to exercise and a reduction of the exercise-associated alterations in cell death. Six well-trained cyclists completed two exercise trials consisting of 2.5 h of cycling at 85% of individual ventilatory threshold. In a random order, trials were completed under either CHO (6% CHO solution, 3.2 g CHO/kg body wt total) or Pl conditions. Blood samples were collected before exercise, midexercise (after 60 min of exercise), immediately after exercise, and after 60 min of recovery. T-lymphocyte responses to mitogen were determined by using carboxyfluorescein diacetate succinimidyl ester fluorescent cell division tracking and expansion rates, and cell death rates were calculated for each sample as well as mitosis rates for each cell generation. Cellular expansion of T lymphocytes was decreased after exercise in Pl only. The reduction in cellular expansion was related to an increase in cell death of both CD4 and CD8 cells in culture rather than a decrease in the ability of cells to undergo mitosis. CHO ingestion compared with Pl was associated with no reductions in cellular expansion or increases in cell death. CHO ingestion during exercise acted to reduce the impairment of T-lymphocyte function by decreasing cell death within mitogen-stimulated cell cultures; however, the mechanism of action appears to be independent of cortisol.

scholarly journals Rosetting of activated human T lymphocytes with autologous erythrocytes. Definition of the receptor and ligand molecules as CD2 and lymphocyte function-associated antigen 3 (LFA-3).

1987 ◽  
Vol 165 (3) ◽  
pp. 664-676 ◽  
Author(s):  
M L Plunkett ◽  
M E Sanders ◽  
P Selvaraj ◽  
M L Dustin ◽  
T A Springer
Keyword(s):  
Cell Adhesion ◽  
T Cell ◽  
T Lymphocytes ◽  
Cell Surface ◽  
T Lymphocyte ◽  
Surface Protein ◽  
Target Cells ◽  
Lymphocyte Function ◽  
Cell Surface Protein ◽  
Definition Of

CD2, also known as LFA-2, T11, and the E rosette receptor, is a T lymphocyte surface protein functionally important in adhesion to target cells and T cell triggering. LFA-3 is a widely distributed cell surface protein that functions in adhesion on target cells. We find that LFA-3 is expressed on human E, and that CD2 is a receptor for LFA-3 that mediates T cell adhesion to human E. Pretreatment of T lymphocytes with CD2 mAb or of E with LFA-3 mAb inhibits rosetting. Purified CD2 molecules bind to human E and inhibit rosetting. 125I-CD2 binding to E is inhibited by LFA-3 mAb; reciprocally, binding of LFA-3 mAb to human E is inhibited by pretreatment with purified CD2. Higher concentrations of CD2 aggregate human E; aggregation is inhibited by mAb to LFA-3.

The integrin LFA-1 signals through ZAP-70 to regulate expression of high-affinity LFA-1 on T lymphocytes

Blood ◽  
2011 ◽  
Vol 117 (12) ◽  
pp. 3331-3342 ◽  
Author(s):  
Rachel Evans ◽  
Annemarie C. Lellouch ◽  
Lena Svensson ◽  
Alison McDowall ◽  
Nancy Hogg
Keyword(s):  
T Lymphocytes ◽  
T Lymphocyte ◽  
Tyrosine Kinases ◽  
Close Contact ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Intercellular Adhesion Molecule 1 ◽  
Lymphocyte Migration ◽  
High Affinity ◽  
And Migration

Abstract The integrin lymphocyte function-associated antigen 1 (LFA-1) controls many functions of T lymphocytes and is particularly essential during lymphocyte migration from blood into tissues. LFA-1 is considered to initiate “outside-in” signaling when bound to ligand intercellular adhesion molecule 1 (ICAM-1), but little is known about the proteins involved or where in the cell such LFA-1–mediated signaling might be operating. Here we show that LFA-1 is constitutively associated with the protein tyrosine kinases Lck and zeta chain–associated protein of 70 kDa (ZAP-70). When LFA-1 binds ICAM-1, both kinases become phosphorylated and the consequence of kinase activation is the conversion of intermediate- to high-affinity LFA-1 and an increase in close contact with ICAM-1. In the polarized T lymphocyte, phospho-ZAP-70 is concentrated within a region of high-affinity LFA-1 that includes talin and encompasses the lamella/lamellipodial interface as well as further back in the cell. Deficiency of ZAP-70 through inhibition or knockdown in T lymphocytes decreases the speed of migration on ICAM-1, as well as reducing firm adhesion under shear-flow conditions. Through its control of high-affinity LFA-1, the LFA-1/Lck/ZAP-70 complex is in position to initiate the rapid adhesion strengthening and migration necessary for T-lymphocyte responses when stimulated vasculature is encountered at sites of infection or injury.

scholarly journals Nonmuscle myosin heavy chain IIA mediates integrin LFA-1 de-adhesion during T lymphocyte migration

2008 ◽  
Vol 205 (1) ◽  
pp. 195-205 ◽  
Author(s):  
Nicole A. Morin ◽  
Patrick W. Oakes ◽  
Young-Min Hyun ◽  
Dooyoung Lee ◽  
Y. Eugene Chin ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Myosin Heavy Chain ◽  
T Lymphocyte ◽  
Heavy Chain ◽  
Total Internal Reflection ◽  
Intercellular Adhesion Molecule ◽  
Lymphocyte Function ◽  
Nonmuscle Myosin ◽  
Lymphocyte Migration ◽  
Temporal Regulation

Precise spatial and temporal regulation of cell adhesion and de-adhesion is critical for dynamic lymphocyte migration. Although a great deal of information has been learned about integrin lymphocyte function–associated antigen (LFA)-1 adhesion, the mechanism that regulates efficient LFA-1 de-adhesion from intercellular adhesion molecule (ICAM)-1 during T lymphocyte migration is unknown. Here, we show that nonmuscle myosin heavy chain IIA (MyH9) is recruited to LFA-1 at the uropod of migrating T lymphocytes, and inhibition of the association of MyH9 with LFA-1 results in extreme uropod elongation, defective tail detachment, and decreased lymphocyte migration on ICAM-1, without affecting LFA-1 activation by chemokine CXCL-12. This defect was reversed by a small molecule antagonist that inhibits both LFA-1 affinity and avidity regulation, but not by an antagonist that inhibits only affinity regulation. Total internal reflection fluorescence microscopy of the contact zone between migrating T lymphocytes and ICAM-1 substrate revealed that inactive LFA-1 is selectively localized to the posterior of polarized T lymphocytes, whereas active LFA-1 is localized to their anterior. Thus, during T lymphocyte migration, uropodal adhesion depends on LFA-1 avidity, where MyH9 serves as a key mechanical link between LFA-1 and the cytoskeleton that is critical for LFA-1 de-adhesion.

scholarly journals FUNCTION OF MACROPHAGES IN ANTIGEN RECOGNITION BY GUINEA PIG T LYMPHOCYTES

1973 ◽  
Vol 138 (5) ◽  
pp. 1213-1229 ◽  
Author(s):  
Ethan M. Shevach ◽  
Alan S. Rosenthal
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Lymphocytes ◽  
Binding Site ◽  
T Lymphocyte ◽  
Lymphocyte Transformation ◽  
Antigen Recognition ◽  
Histocompatibility Antigens ◽  
Recognition Sites

A number of recent studies have suggested that the main functional role of the product of the immune response (Ir) genes is in the process of antigen recognition by the T lymphocyte. The observation in the accompanying report that the interaction of macrophage-associated antigen with immune T lymphocytes requires that both cells share histocompatibility antigens raised the question as to whether the macrophage played a role in the genetic control of the immune response or even if the macrophage were the primary cell in which the product of the Ir gene is expressed. In the current study, parental macrophages were pulsed with an antigen, the response to which is controlled by an Ir gene lacking in that parent; these macrophages were then mixed with T cells derived from the (nonresponder x responder)F1 and the resultant stimulation was measured. No stimulation was seen when column-purified F1 lymph node lymphocytes were mixed with antigen-pulsed macrophages from the nonresponder parent. However, when the highly reactive peritoneal exudate lymphocyte population was used as the indicator cells, parental macrophages pulsed with an antigen whose Ir gene they lacked were capable of initiating F1 T-cell proliferation. The magnitude of stimulation was approximately 1/10 that seen when macrophages from either the responder parent or the F1 were used. In order to explain this observation, we hypothesize that antigen recognition sites on the T lymphocyte are physically related to a macrophage-binding site and both are linked to the serologically determined histocompatibility antigens. Thus, parental macrophages pulsed with an antigen, whose Ir gene they lack, activate F1 cells poorly because the recognition sites for the antigen are physically related to the macrophage-binding site of the responder parent while the main contacts between the cells are at the nonresponder binding sites. Experiments performed with alloantisera lend support to this hypothesis. Thus, when parental macrophages are pulsed with any antigen and added to F1 T cells, an alloantiserum directed against parental histocompatibility antigens reacts with both the lymphocyte and the macrophage and thereby inhibits macrophage-lymphocyte interaction and abolishes antigen-induced lymphocyte transformation. When the alloantisera are directed at determinants present solely on the T lymphocyte, they only inhibit the recognition of antigens controlled by the Ir gene linked to the histocompatibility antigen against which they are directed. We conclude from these studies that antigen recognition by the T lymphocyte is a complex multicellular event involving more than simple antigen binding to a specific lymphocyte receptor.

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