scholarly journals Novel immune checkpoint targets: moving beyond PD-1 and CTLA-4

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Shuang Qin ◽  
Linping Xu ◽  
Ming Yi ◽  
Shengnan Yu ◽  
Kongming Wu ◽  
...  

Abstract The emergence of immune checkpoint inhibitors (ICIs), mainly including anti-programmed cell death protein 1/programmed cell death ligand 1 (PD-1/PD-L1) and anti-cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) monoclonal antibodies (mAbs), has shaped therapeutic landscape of some type of cancers. Despite some ICIs have manifested compelling clinical effectiveness in certain tumor types, the majority of patients still showed de novo or adaptive resistance. At present, the overall efficiency of immune checkpoint therapy remains unsatisfactory. Exploring additional immune checkpoint molecules is a hot research topic. Recent studies have identified several new immune checkpoint targets, like lymphocyte activation gene-3 (LAG-3), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), V-domain Ig suppressor of T cell activation (VISTA), and so on. The investigations about these molecules have generated promising results in preclinical studies and/or clinical trials. In this review, we discussed the structure and expression of these newly-characterized immune checkpoints molecules, presented the current progress and understanding of them. Moreover, we summarized the clinical data pertinent to these recent immune checkpoint molecules as well as their application prospects.

Author(s):  
Nádia Ghinelli Amôr ◽  
Paulo Sérgio da Silva Santos ◽  
Ana Paula Campanelli

Squamous cell carcinoma (SCC) is the second most common skin cancer worldwide and, despite the relatively easy visualization of the tumor in the clinic, a sizeable number of SCC patients are diagnosed at advanced stages with local invasion and distant metastatic lesions. In the last decade, immunotherapy has emerged as the fourth pillar in cancer therapy via the targeting of immune checkpoint molecules such as programmed cell-death protein-1 (PD-1), programmed cell death ligand-1 (PD-L1), and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). FDA-approved monoclonal antibodies directed against these immune targets have provide survival benefit in a growing list of cancer types. Currently, there are two immunotherapy drugs available for cutaneous SCC: cemiplimab and pembrolizumab; both monoclonal antibodies (mAb) that block PD-1 thereby promoting T-cell activation and/or function. However, the success rate of these checkpoint inhibitors currently remains around 50%, which means that half of the patients with advanced SCC experience no benefit from this treatment. This review will highlight the mechanisms by which the immune checkpoint molecules regulate the tumor microenvironment (TME), as well as the ongoing clinical trials that are employing single or combinatory therapeutic approaches for SCC immunotherapy. We also discuss the regulation of additional pathways that might promote superior therapeutic efficacy, and consequently provide increased survival for those patients that do not benefit from the current checkpoint inhibitor therapies.


ESMO Open ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. e000544 ◽  
Author(s):  
Cinzia Solinas ◽  
Chunyan Gu-Trantien ◽  
Karen Willard-Gallo

Inducible T cell costimulator (ICOS, cluster of differentiation (CD278)) is an activating costimulatory immune checkpoint expressed on activated T cells. Its ligand, ICOSL is expressed on antigen-presenting cells and somatic cells, including tumour cells in the tumour microenvironment. ICOS and ICOSL expression is linked to the release of soluble factors (cytokines), induced by activation of the immune response. ICOS and ICOSL binding generates various activities among the diversity of T cell subpopulations, including T cell activation and effector functions and when sustained also suppressive activities mediated by regulatory T cells. This dual role in both antitumour and protumour activities makes targeting the ICOS/ICOSL pathway attractive for enhancement of antitumour immune responses. This review summarises the biological background and rationale for targeting ICOS/ICOSL in cancer together with an overview of the principal ongoing clinical trials that are testing it in combination with anti-cytotoxic T lymphocyte antigen-4 and anti-programmed cell death-1 or anti-programmed cell death ligand-1 based immune checkpoint blockade.


2021 ◽  
Vol 11 ◽  
Author(s):  
Bonnie L. Russell ◽  
Selisha A. Sooklal ◽  
Sibusiso T. Malindisa ◽  
Lembelani Jonathan Daka ◽  
Monde Ntwasa

Through genetic and epigenetic alterations, cancer cells present the immune system with a diversity of antigens or neoantigens, which the organism must distinguish from self. The immune system responds to neoantigens by activating naïve T cells, which mount an anticancer cytotoxic response. T cell activation begins when the T cell receptor (TCR) interacts with the antigen, which is displayed by the major histocompatibility complex (MHC) on antigen-presenting cells (APCs). Subsequently, accessory stimulatory or inhibitory molecules transduce a secondary signal in concert with the TCR/antigen mediated stimulus. These molecules serve to modulate the activation signal’s strength at the immune synapse. Therefore, the activation signal’s optimum amplitude is maintained by a balance between the costimulatory and inhibitory signals. This system comprises the so-called immune checkpoints such as the programmed cell death (PD-1) and Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and is crucial for the maintenance of self-tolerance. Cancers often evade the intrinsic anti-tumor activity present in normal physiology primarily by the downregulation of T cell activation. The blockade of the immune checkpoint inhibitors using specific monoclonal antibodies has emerged as a potentially powerful anticancer therapy strategy. Several drugs have been approved mainly for solid tumors. However, it has emerged that there are innate and acquired mechanisms by which resistance is developed against these therapies. Some of these are tumor-intrinsic mechanisms, while others are tumor-extrinsic whereby the microenvironment may have innate or acquired resistance to checkpoint inhibitors. This review article will examine mechanisms by which resistance is mounted against immune checkpoint inhibitors focussing on anti-CTL4-A and anti-PD-1/PD-Ll since drugs targeting these checkpoints are the most developed.


2012 ◽  
Vol 209 (6) ◽  
pp. 1201-1217 ◽  
Author(s):  
Tadashi Yokosuka ◽  
Masako Takamatsu ◽  
Wakana Kobayashi-Imanishi ◽  
Akiko Hashimoto-Tane ◽  
Miyuki Azuma ◽  
...  

Programmed cell death 1 (PD-1) is a negative costimulatory receptor critical for the suppression of T cell activation in vitro and in vivo. Single cell imaging elucidated a molecular mechanism of PD-1–mediated suppression. PD-1 becomes clustered with T cell receptors (TCRs) upon binding to its ligand PD-L1 and is transiently associated with the phosphatase SHP2 (Src homology 2 domain–containing tyrosine phosphatase 2). These negative costimulatory microclusters induce the dephosphorylation of the proximal TCR signaling molecules. This results in the suppression of T cell activation and blockade of the TCR-induced stop signal. In addition to PD-1 clustering, PD-1–TCR colocalization within microclusters is required for efficient PD-1–mediated suppression. This inhibitory mechanism also functions in PD-1hi T cells generated in vivo and can be overridden by a neutralizing anti–PD-L1 antibody. Therefore, PD-1 microcluster formation is important for regulation of T cell activation.


2019 ◽  
Vol 20 (16) ◽  
pp. 3934 ◽  
Author(s):  
Gilda Varricchi ◽  
Stefania Loffredo ◽  
Giancarlo Marone ◽  
Luca Modestino ◽  
Poupak Fallahi ◽  
...  

Immune cells play critical roles in tumor prevention as well as initiation and progression. However, immune-resistant cancer cells can evade the immune system and proceed to form tumors. The normal microenvironment (immune cells, fibroblasts, blood and lymphatic vessels, and interstitial extracellular matrix (ECM)) maintains tissue homeostasis and prevents tumor initiation. Inflammatory mediators, reactive oxygen species, cytokines, and chemokines from an altered microenvironment promote tumor growth. During the last decade, thyroid cancer, the most frequent cancer of the endocrine system, has emerged as the fifth most incident cancer in the United States (USA), and its incidence is steadily growing. Inflammation has long been associated with thyroid cancer, raising critical questions about the role of immune cells in its pathogenesis. A plethora of immune cells and their mediators are present in the thyroid cancer ecosystem. Monoclonal antibodies (mAbs) targeting immune checkpoints, such as mAbs anti-cytotoxic T lymphocyte antigen 4 (anti-CTLA-4) and anti-programmed cell death protein-1/programmed cell death ligand-1 (anti-PD-1/PD-L1), have revolutionized the treatment of many malignancies, but they induce thyroid dysfunction in up to 10% of patients, presumably by enhancing autoimmunity. Combination strategies involving immune checkpoint inhibitors (ICIs) with tyrosine kinase (TK) or serine/threonine protein kinase B-raf (BRAF) inhibitors are showing considerable promise in the treatment of advanced thyroid cancer. This review illustrates how different immune cells contribute to thyroid cancer development and the rationale for the antitumor effects of ICIs in combination with BRAF/TK inhibitors.


2019 ◽  
Vol 27 (S2) ◽  
Author(s):  
R.R. Kansara ◽  
C. Speziali

The management of hematologic malignancies has traditionally relied on chemotherapy regimens, many of which are still in use today. However, with advancements in the knowledge of tumour pathophysiology, therapies are continually evolving. Monoclonal antibodies against specific targets on tumour cells are now widely used to treat hematologic malignancies, either in combination with chemotherapy or as single agents. Rituximab, a monoclonal antibody against the CD20 antigen, is a good example of successful monoclonal antibody therapy that has improved outcomes for patients with B cell non-Hodgkin lymphomas. Monoclonal antibodies are now being used against the immune checkpoints that function to inhibit T cell activation and subsequent tumour eradication by those cytotoxic T cells. Such therapies enhance T cell–mediated tumour eradication and are widely successful in treating patients with solid tumours such as malignant melanoma. Now, they are slowly finding their place in the management of hematologic neoplasms. Even though, currently, immune checkpoint inhibitors are used for relapsed or refractory hematologic neoplasms, trials are ongoing to evaluate their role in frontline treatment. Our review focuses on the current use of immunotherapies in various hematologic malignancies.


2018 ◽  
Vol 11 (2) ◽  
pp. 549-556 ◽  
Author(s):  
Yoshito Nishimura ◽  
Miho Yasuda ◽  
Kazuki Ocho ◽  
Masaya Iwamuro ◽  
Osamu Yamasaki ◽  
...  

Immune checkpoint inhibitors such as ipilimumab, a cytotoxic T-lymphocyte-associated antigen-4 inhibitor, have been widely used for advanced malignancies. As these inhibitors improve antitumor immunity via T-cell modulation, immune-mediated adverse events associated with T-cell activation, such as colitis, might occur. Herein, we describe a 75-year-old Japanese woman with metastatic malignant melanoma who developed hemorrhagic gastritis after ipilimumab treatment. There was no macroscopic or clinical improvement of gastritis after proton pump inhibitor treatment. However, her condition improved after approximately 3 weeks of corticosteroid therapy and Helicobacter pylori eradication. This case suggests a potential association between severe gastritis and immune checkpoint inhibitor treatment. Although several reports have mentioned ipilimumab-associated colitis, gastritis is considered to be rare. In the present case, H. pylori-associated gastritis might have been exacerbated by the T-cell modulation effect of ipilimumab. To date, no report has clarified the mechanism by which ipilimumab modifies H. pylori infection. The present treatment course provides a helpful perspective for similar cases.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Julian A. Marin-Acevedo ◽  
ErinMarie O. Kimbrough ◽  
Yanyan Lou

AbstractThe immune system is the core defense against cancer development and progression. Failure of the immune system to recognize and eliminate malignant cells plays an important role in the pathogenesis of cancer. Tumor cells evade immune recognition, in part, due to the immunosuppressive features of the tumor microenvironment. Immunotherapy augments the host immune system to generate an antitumor effect. Immune checkpoints are pathways with inhibitory or stimulatory features that maintain self-tolerance and assist with immune response. The most well-described checkpoints are inhibitory in nature and include the cytotoxic T lymphocyte-associated molecule-4 (CTLA-4), programmed cell death receptor-1 (PD-1), and programmed cell death ligand-1 (PD-L1). Molecules that block these pathways to enhance the host immunologic activity against tumors have been developed and become standard of care in the treatment of many malignancies. Only a small percentage of patients have meaningful responses to these treatments, however. New pathways and molecules are being explored in an attempt to improve responses and application of immune checkpoint inhibition therapy. In this review, we aim to elucidate these novel immune inhibitory pathways, potential therapeutic molecules that are under development, and outline particular advantages and challenges with the use of each one of them.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3677-3677
Author(s):  
Christina Krupka ◽  
Thomas Köhnke ◽  
Peter Kufer ◽  
Roman Kischel ◽  
Felix S. Lichtenegger ◽  
...  

Abstract In our previous work, we showed elimination of primary acute myeloid leukemia (AML) cells by CD33/CD3 BiTE® antibody construct (AMG 330) mediated cytotoxicity (Krupka et al, Blood 2014). The goal of the present study was to identify innate and adaptive resistance mechanisms to AMG 330 mediated lysis of AML cells. Immune checkpoint molecules have been shown to be a highly relevant escape mechanism of malignant cells to evade innate and adaptive immunity. Previously, it was shown that AML cells upregulate the expression of inhibitory ligands in response to proinflammatory cytokines (Krönig et al, 2014). As AMG 330 mediated T-cell activation induces high levels of the proinflammatory cytokines IFNγ and TNFα, we assessed the constitutive and inducible expression profile of different immune checkpoint molecules on AML cell lines and primary AML cells, including PD-L1, HVEM, ILT3 and SLAMF7 by flow cytometry. No constitutive expression was observed for PD-L1 at time of primary diagnosis in 83.7% of the cases (103/123). In contrast, constitutive expression of HVEM and ILT3 was detected in 73.7% (42/57) and 91.9% (68/74) of patient samples, respectively. Adaptive resistance was evaluated by incubating AML cell lines and primary AML samples with IFNγ and TNFα. We observed an upregulation of PD-L1 and SLAMF7 on AML cell lines and on primary AML patient samples whereas HVEM and ILT3 did not show a significant change in expression level. To test the functional relevance of the immune checkpoint molecules upon AMG 330 mediated lysis, we used an ex vivo long term culture system that enabled us to analyse the dynamic process of receptor-ligand interaction over time. Blockade of the PD-1/PD-L1 interaction resulted in a significantly increase in AMG 330 mediated lysis of primary AML cells (n=9, p=0.03). Currently, blockade of the inducible molecule SLAMF7 in AMG 330 mediated cytotoxicity is being tested. Blocking of HVEM or ILT3 did not result in a significant increase in T cell activation and concomitant lysis of AML cells suggesting a less relevant role of HVEM and ILT3 in resistance to AMG 330 mediated cytotoxicity. The latter might also be influenced by the cytokine microenvironment which favours immune resistance of AML cells. Using a bead based multiplex assay we screened the bone marrow (BM) plasma from 16 AML patients and 3 healthy donors (HD) for the presence of 33 cytokines. The cytokine profile differed between AML patients and healthy donors (HDs). The plasma levels of IL-8, IP-10 and CXCL-16 were higher in the AML samples compared to those of HDs (p=0.0041, 0.0248 and 0.0289, respectively). In contrast, EGF, FLT3-ligand, RANTES and IL-4 were significantly lower in AML samples compared to HDs (p=0.0227, 0.0145, 0.0041 and 0.0041, respectively). However, we did observe a high inter-patient variability of cytokine composition in AML. To explore the functional relevance of the BM plasma on AMG 330 mediated cytotoxicity, cocultures of AML cell lines and HD T cells were set up using different sources of plasma including fetal calf serum (FCS) and patient derived BM plasma. Interestingly, AMG 330 mediated cytotoxicity was significantly reduced using patient derived BM plasma (n=5) compared to cultures containing FCS (n=4) (mean % lysis FCS 97.4 vs PT 70.6). This was accompanied by a considerable impairment in T-cell proliferation (mean % proliferation FKS 44.7% vs PT 26.6%). Currently, we are investigating which soluble factors are responsible for the immunosuppressive effects and if we can increase lysis efficacy and T-cell proliferation through specific blocking of them. In summary we have identified possible resistance mechanisms of AML cells to AMG 330 mediated cytotoxicity. Dynamic receptor-ligand interactions between target and effector cells as well as soluble factors contribute to AMG 330 mediated lysis of primary AML cells. We hypothesize that AMG 330 mediated cytotoxicity can be augmented through combinatorial approaches including PD-1 blockade. The significance of our findings will first be validated in an in vivo mouse model and prospectively translated into human studies. Disclosures Krupka: AMGEN Research (Munich): Research Funding. Kufer:AMGEN Research (Munich): Employment, Equity Ownership. Kischel:AMGEN Research (Munich): Employment, Equity Ownership. Subklewe:AMGEN Research (Munich): Research Funding.


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