The Immune System: Strand Swapping for T-Cell Inhibition

2013 ◽  
Author(s):  
Michael A. Durney
Keyword(s):  
Immune System ◽  
T Cell ◽  
Cell Inhibition

Cancer Immunology

2015 ◽  
Author(s):  
Clifford S. Cho ◽  
Amanda Contreras
Keyword(s):  
Immune System ◽  
T Cell ◽  
Cell Function ◽  
Cytotoxic T Lymphocyte ◽  
Continuous Process ◽  
Effective Means ◽  
Full Complement ◽  
Activated T Cell ◽  
Antigen Presenting ◽  
Cell Inhibition

The immune system conducts a continuous process of immunologic surveillance for new cancer cells that is likely capable of eradicating many potential malignancies before they become clinically evident. Nascent tumors can, however, use escape mechanisms to avoid this control. It is hoped that therapeutic manipulation of this balance between cancer and host may allow us to harness the immune system as an effective means of treating established tumors. This review summarizes the immunologic response, immunoediting, and clinical strategies in cancer immunotherapy. Figures show activation of CD8+ cytotoxic T lymphocytes and CD4+ T helper cells by an antigen-presenting cell; inhibition of T cells specific for an antigen being presented in the absence of a full complement of costimulatory interactions, as might be present on an immature dendritic cell, engagement of cytotoxic T lymphocyte–associated protein 4 by B7, which serves to downregulate T cell function, and downregulation of major histocompatibility proteins on the surfaces of tumor cells; and the kinetics of activated T cell homeostasis in the presence of cancer. This review contains 3 figures and 39 references.

scholarly journals Synthetic mycobacterial diacyl trehaloses reveal differential recognition by human T cell receptors and the C-type lectin Mincle

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Josephine F. Reijneveld ◽  
Mira Holzheimer ◽  
David C. Young ◽  
Kattya Lopez ◽  
Sara Suliman ◽  
...  
Keyword(s):  
T Cells ◽  
Fatty Acid ◽  
Immune System ◽  
T Cell ◽  
Cross Reactivity ◽  
Lipid Binding ◽  
Human Immune System ◽  
Human T Cell ◽  
Human T Cells ◽  
Pure Compounds

AbstractThe cell wall of Mycobacterium tuberculosis is composed of diverse glycolipids which potentially interact with the human immune system. To overcome difficulties in obtaining pure compounds from bacterial extracts, we recently synthesized three forms of mycobacterial diacyltrehalose (DAT) that differ in their fatty acid composition, DAT1, DAT2, and DAT3. To study the potential recognition of DATs by human T cells, we treated the lipid-binding antigen presenting molecule CD1b with synthetic DATs and looked for T cells that bound the complex. DAT1- and DAT2-treated CD1b tetramers were recognized by T cells, but DAT3-treated CD1b tetramers were not. A T cell line derived using CD1b-DAT2 tetramers showed that there is no cross-reactivity between DATs in an IFN-γ release assay, suggesting that the chemical structure of the fatty acid at the 3-position determines recognition by T cells. In contrast with the lack of recognition of DAT3 by human T cells, DAT3, but not DAT1 or DAT2, activates Mincle. Thus, we show that the mycobacterial lipid DAT can be both an antigen for T cells and an agonist for the innate Mincle receptor, and that small chemical differences determine recognition by different parts of the immune system.

scholarly journals Interleukins and Interleukin Receptors Evolutionary History and Origin in Relation to CD4+ T Cell Evolution

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 813
Author(s):  
Norwin Kubick ◽  
Pavel Klimovich ◽  
Patrick Henckell Flournoy ◽  
Irmina Bieńkowska ◽  
Marzena Łazarczyk ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Positive Selection ◽  
Cd4 T Cells ◽  
Cell Function ◽  
Single Gene ◽  
Ancestral Reconstruction ◽  
Critical Function ◽  
Interleukin Receptors

Understanding the evolution of interleukins and interleukin receptors is essential to control the function of CD4+ T cells in various pathologies. Numerous aspects of CD4+ T cells’ presence are controlled by interleukins including differentiation, proliferation, and plasticity. CD4+ T cells have emerged during the divergence of jawed vertebrates. However, little is known about the evolution of interleukins and their origin. We traced the evolution of interleukins and their receptors from Placozoa to primates. We performed phylogenetic analysis, ancestral reconstruction, HH search, and positive selection analysis. Our results indicated that various interleukins' emergence predated CD4+ T cells divergence. IL14 was the most ancient interleukin with homologs in fungi. Invertebrates also expressed various interleukins such as IL41 and IL16. Several interleukin receptors also appeared before CD4+ T cells divergence. Interestingly IL17RA and IL17RD, which are known to play a fundamental role in Th17 CD4+ T cells first appeared in mollusks. Furthermore, our investigations showed that there is not any single gene family that could be the parent group of interleukins. We postulate that several groups have diverged from older existing cytokines such as IL4 from TGFβ, IL10 from IFN, and IL28 from BCAM. Interleukin receptors were less divergent than interleukins. We found that IL1R, IL7R might have diverged from a common invertebrate protein that contained TIR domains, conversely, IL2R, IL4R and IL6R might have emerged from a common invertebrate ancestor that possessed a fibronectin domain. IL8R seems to be a GPCR that belongs to the rhodopsin-like family and it has diverged from the Somatostatin group. Interestingly, several interleukins that are known to perform a critical function for CD4+ T cells such as IL6, IL17, and IL1B have gained new functions and evolved under positive selection. Overall evolution of interleukin receptors was not under significant positive selection. Interestingly, eight interleukin families appeared in lampreys, however, only two of them (IL17B, IL17E) evolved under positive selection. This observation indicates that although lampreys have a unique adaptive immune system that lacks CD4+ T cells, they could be utilizing interleukins in homologous mode to that of the vertebrates' immune system. Overall our study highlights the evolutionary heterogeneity within the interleukins and their receptor superfamilies and thus does not support the theory that interleukins evolved solely in jawed vertebrates to support T cell function. Conversely, some of the members are likely to play conserved functions in the innate immune system.

scholarly journals Rethinking immune checkpoint blockade: ‘Beyond the T cell’

2021 ◽  
Vol 9 (1) ◽  
pp. e001460 ◽  
Author(s):  
Xiuting Liu ◽  
Graham D Hogg ◽  
David G DeNardo
Keyword(s):  
Immune System ◽  
T Cell ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Antitumor Immunity ◽  
Checkpoint Inhibitors ◽  
Clinical Success ◽  
Immune Checkpoint Blockade ◽  
Checkpoint Blockade

The clinical success of immune checkpoint inhibitors has highlighted the central role of the immune system in cancer control. Immune checkpoint inhibitors can reinvigorate anti-cancer immunity and are now the standard of care in a number of malignancies. However, research on immune checkpoint blockade has largely been framed with the central dogma that checkpoint therapies intrinsically target the T cell, triggering the tumoricidal potential of the adaptive immune system. Although T cells undoubtedly remain a critical piece of the story, mounting evidence, reviewed herein, indicates that much of the efficacy of checkpoint therapies may be attributable to the innate immune system. Emerging research suggests that T cell-directed checkpoint antibodies such as anti-programmed cell death protein-1 (PD-1) or programmed death-ligand-1 (PD-L1) can impact innate immunity by both direct and indirect pathways, which may ultimately shape clinical efficacy. However, the mechanisms and impacts of these activities have yet to be fully elucidated, and checkpoint therapies have potentially beneficial and detrimental effects on innate antitumor immunity. Further research into the role of innate subsets during checkpoint blockade may be critical for developing combination therapies to help overcome checkpoint resistance. The potential of checkpoint therapies to amplify innate antitumor immunity represents a promising new field that can be translated into innovative immunotherapies for patients fighting refractory malignancies.

scholarly journals Neonatal lymphocyte subpopulations analysis and maternal preterm premature rupture of membranes: a pilot study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Margherita Amadi ◽  
Silvia Visentin ◽  
Francesca Tosato ◽  
Paola Fogar ◽  
Giulia Giacomini ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
T Helper Cells ◽  
Lymphocyte Subpopulations ◽  
T Helper ◽  
Premature Rupture Of Membranes ◽  
Premature Rupture ◽  
Preterm Premature Rupture ◽  
Helper Cells

Abstract Objectives Preterm premature rupture of membranes (pPROM) causes preterm delivery, and increases maternal T-cell response against the fetus. Fetal inflammatory response prompts maturation of the newborn’s immunocompetent cells, and could be associated with unfavorable neonatal outcome. The aims were to examine the effects of pPROM (Mercer BM. Preterm premature rupture of the membranes: current approaches to evaluation and management. Obstet Gynecol Clin N Am 2005;32:411) on the newborn’s and mother’s immune system and (Test G, Levy A, Wiznitzer A, Mazor M, Holcberg G, Zlotnik A, et al. Factors affecting the latency period in patients with preterm premature rupture of membranes (pPROM). Arch Gynecol Obstet 2011;283:707–10) to assess the predictive value of immune system changes in neonatal morbidity. Methods Mother-newborn pairs (18 mothers and 23 newborns) who experienced pPROM and controls (11 mothers and 14 newborns), were enrolled. Maternal and neonatal whole blood samples underwent flow cytometry to measure lymphocyte subpopulations. Results pPROM-newborns had fewer naïve CD4 T-cells, and more memory CD4 T-cells than control newborns. The effect was the same for increasing pPROM latency times before delivery. Gestational age and birth weight influenced maturation of the newborns’ lymphocyte subpopulations and white blood cells, notably cytotoxic T-cells, regulatory T-cells, T-helper cells (absolute count), and CD4/CD8 ratio. Among morbidities, fewer naïve CD8 T-cells were found in bronchopulmonary dysplasia (BPD) (p=0.0009), and more T-helper cells in early onset sepsis (p=0.04). Conclusions pPROM prompts maturation of the newborn’s T-cell immune system secondary to antigenic stimulation, which correlates with pPROM latency. Maternal immunity to inflammatory conditions is associated with a decrease in non-major histocompatibility complex (MHC)-restricted cytotoxic cells.

721 AT1412, a patient-derived CD9 antibody in preclinical development promoting tumor immune infiltration and inducing tumor rejection

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A763-A763
Author(s):  
Remko Schotte ◽  
Julien Villaudy ◽  
Martijn Kedde ◽  
Wouter Pos ◽  
Daniel Go ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Tumor Cells ◽  
Tumor Rejection ◽  
Human Immune System ◽  
Preclinical Development ◽  
High Affinity ◽  
Human Immune ◽  
A375 Melanoma

BackgroundAdaptive immunity to cancer cells forms a crucial part of cancer immunotherapy. Recently, the importance of tumor B-cell signatures were shown to correlate with melanoma survival. We investigated whether tumor-targeting antibodies could be isolated from a patient that cured (now 13 years tumor-free) metastatic melanoma following adoptive transfer of ex vivo expanded autologous T cells.MethodsPatient‘s peripheral blood B cells were isolated and tested for the presence of tumor-reactive B cells using AIMM’s immmortalisation technology. Antibody AT1412 was identified by virtue of its differential binding to melanoma cells as compared to healthy melanocytes. AT1412 binds the tetraspanin CD9, a broadly expressed protein involved in multiple cellular activities in cancer and induces ADCC and ADCP by effector cells.ResultsSpontaneous immune rejection of tumors was observed in human immune system (HIS) mouse models implanted with CD9 genetically-disrupted A375 melanoma (A375-CD9KO) tumor cells, while A375wt cells were not cleared. Most notably, no tumor rejection of A375-CD9KO tumors was observed in NSG mice, indicating that blockade of CD9 makes tumor cells susceptible to immune rejection.CD9 has been described to regulate integrin signaling, e.g. LFA-1, VLA-4, VCAM-1 and ICAM-1. AT1412 was shown to modulate CD9 function by enhancing adhesion and transmigration of T cells to endothelial (HUVEC) cells. AT1412 was most potently enhancing transendothelial T-cell migration, in contrast to a high affinity version of AT1412 or other high affinity anti-CD9 reference antibodies (e.g. ALB6). Enhanced immune cell infiltration is also observed in immunodeficient mice harbouring a human immune system (HIS). AT1412 strongly enhanced CD8 T-cell and macrophage infiltration resulting in tumor rejection (A375 melanoma). PD-1 checkpoint blockade is further sustaining this effect. In a second melanoma model carrying a PD-1 resistant and highly aggressive tumor (SK-MEL5) AT1412 together with nivolumab was inducing full tumor rejection, while either one of the antibodies alone did not.ConclusionsThe safety of AT1412 has been assessed in preclinical development and is well tolerated up to 10 mg/kg (highest dose tested) by non human primates. AT1412 demonstrated a half-life of 8.5 days, supporting 2–3 weekly administration in humans. Besides transient thrombocytopenia no other pathological deviations were observed. No effect on coagulation parameters, bruising or bleeding were observed macro- or microscopically. The thrombocytopenia is reversible, and its recovery accelerated in those animals developing anti-drug antibodies. First in Human clinical study is planned to start early 2021.Ethics ApprovalStudy protocols were approved by the Medical Ethical Committee of the Leiden University Medical Center (Leiden, Netherlands).ConsentBlood was obtained after written informed consent by the patient.

T-Cell Immunity to the Folate Receptor Alpha Is Prevalent in Women With Breast or Ovarian Cancer

2006 ◽  
Vol 24 (26) ◽  
pp. 4254-4261 ◽  
Author(s):  
Keith L. Knutson ◽  
Christopher J. Krco ◽  
Courtney L. Erskine ◽  
Karin Goodman ◽  
Linda E. Kelemen ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Immune System ◽  
T Cell ◽  
Cancer Patients ◽  
Folate Receptor ◽  
Prediction Algorithm ◽  
Amino Terminus ◽  
Folate Receptor Alpha ◽  
Receptor Alpha ◽  
Healthy Donors

Purpose Studies have demonstrated that the generation of immunity to tumor antigens is associated with improved prognosis for many cancers. A candidate antigen is the folate receptor alpha (FRα), which is overexpressed in breast and ovarian cancers. Our goal in this study was to attain a better understanding of the extent of endogenous FRα immunity. Methods Using a CD4+ T cell epitope prediction algorithm, we predicted promiscuous epitopes of FRα, and tested for immunity in 30 breast (n = 17) or ovarian (n = 13) cancer patients and 18 healthy donors using enzyme-linked immunospot analysis. Results Fourteen peptides were predicted, seven each from the carboxy- and amino-terminus halves of the protein. More than 70% of patients demonstrated immunity to at least one FRα peptide. Patients responded to an average of 3 ± 0.5 peptides, whereas healthy donors responded to 1 ± 0.4 peptides (P = .004). Five peptides were recognized by more than 25% of patients. Responses to three peptides were higher (P < .05) in patients than in healthy donors, suggesting augmented immunity. Compared with healthy individuals, patients developed higher immunity to the amino-terminus half of the receptor (P = .03). There was no difference between each group in the responses to nonspecific (P = .2) and viral stimuli (P = .5). Lastly, patients demonstrated elevated levels of FRα antibodies consistent with a coordinated immune response. Conclusion These findings demonstrate that the FRα is a target of the immune system in breast and ovarian cancer patients. Understanding which antigens are targeted by the immune system may be important for prognosis or immune-based therapies.

scholarly journals Dendritic Cell Inhibition Is Connected to Exhaustion of CD8+ T Cell Polyfunctionality during Chronic Hepatitis C Virus Infection

2010 ◽  
Vol 184 (6) ◽  
pp. 3134-3144 ◽  
Author(s):  
Ian Gaël Rodrigue-Gervais ◽  
Hawley Rigsby ◽  
Loubna Jouan ◽  
Dominike Sauvé ◽  
Rafick-Pierre Sékaly ◽  
...  
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
T Cell ◽  
Dendritic Cell ◽  
Virus Infection ◽  
Cd8 T Cell ◽  
Hepatitis C Virus Infection ◽  
Chronic Hepatitis C Virus ◽  
Cell Inhibition

scholarly journals T-bet-Deficient NOD Mice Are Protected from Diabetes Due to Defects in Both T Cell and Innate Immune System Function

2009 ◽  
Vol 183 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Jonathan H. Esensten ◽  
Michael R. Lee ◽  
Laurie H. Glimcher ◽  
Jeffrey A. Bluestone
Keyword(s):  
Immune System ◽  
T Cell ◽  
Innate Immune System ◽  
Nod Mice ◽  
Innate Immune ◽  
System Function ◽  
Immune System Function
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