scholarly journals T follicular helper cell expansion and chronic T cell activation are characteristic immune anomalies in Evans syndrome

Blood ◽  
2021 ◽  
Author(s):  
Deepak Kumar ◽  
Chengyu Prince ◽  
Carolyn M. Bennett ◽  
Michael Briones ◽  
Laura Lucas ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
Genetic Defects ◽  
Evans Syndrome ◽  
Inborn Errors ◽  
Immune Parameters ◽  
Follicular Helper ◽  
T Follicular Helper Cell

Pediatric Evans syndrome (pES) is increasingly identified as the presenting manifestation of several inborn errors of immunity (IEI). Despite an improved understanding of genetic defects in pES, the underlying immunobiology of pES is poorly defined, and characteristic diagnostic immune parameters are lacking. We describe the immune characteristics of 24 patients with pES and compared them with 22 patients with chronic immune thrombocytopenia (cITP) and 24 healthy controls (HC). Compared to patients with cITP and HC, patients with pES had increased circulating T-follicular helper cells (cTfh), increased T cell activation, and decreased naïve CD4+ T cells for age. Despite normal or high IgG in the majority of pES at presentation, class-switched memory B cells (CSMB) were decreased. Within the cTfh subset, we noted features of post-activation exhaustion with upregulation of several canonical checkpoint inhibitors. TCR-b repertoire analysis of cTfh cells revealed increased oligoclonality in patients with pES compared with HC. Among patients with pES, those without a known gene defect had a similar characteristic immune abnormality as patients with defined genetic defects. Similarly, patients with pES with normal IgG had similar T cell abnormalities as patients with low IgG. Since genetic defects have been identified in only less than half of patients with pES, our findings of similar immune abnormalities across all pES patients help establish a common characteristic immunopathology in pES irrespective of the underlying genetic etiology.

scholarly journals Dendritic Cell Tumor Vaccination via Fc Gamma Receptor Targeting: Lessons Learned from Pre-Clinical and Translational Studies

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 409
Author(s):  
Enrique Gómez Alcaide ◽  
Sinduya Krishnarajah ◽  
Fabian Junker
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Tumor Antigens ◽  
Checkpoint Inhibitors ◽  
Critical Role ◽  
Lessons Learned ◽  
Antigen Delivery ◽  
Tumor Vaccination ◽  
Translational Studies

Despite significant recent improvements in the field of immunotherapy, cancer remains a heavy burden on patients and healthcare systems. In recent years, immunotherapies have led to remarkable strides in treating certain cancers. However, despite the success of checkpoint inhibitors and the advent of cellular therapies, novel strategies need to be explored to (1) improve treatment in patients where these approaches fail and (2) make such treatments widely and financially accessible. Vaccines based on tumor antigens (Ag) have emerged as an innovative strategy with the potential to address these areas. Here, we review the fundamental aspects relevant for the development of cancer vaccines and the critical role of dendritic cells (DCs) in this process. We first offer a general overview of DC biology and routes of Ag presentation eliciting effective T cell-mediated immune responses. We then present new therapeutic avenues specifically targeting Fc gamma receptors (FcγR) as a means to deliver antigen selectively to DCs and its effects on T-cell activation. We present an overview of the mechanistic aspects of FcγR-mediated DC targeting, as well as potential tumor vaccination strategies based on preclinical and translational studies. In particular, we highlight recent developments in the field of recombinant immune complex-like large molecules and their potential for DC-mediated tumor vaccination in the clinic. These findings go beyond cancer research and may be of relevance for other disease areas that could benefit from FcγR-targeted antigen delivery, such as autoimmunity and infectious diseases.

scholarly journals PPARγ Negatively Regulates T Cell Activation to Prevent Follicular Helper T Cells and Germinal Center Formation

PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e99127 ◽  
Author(s):  
Hong-Jai Park ◽  
Do-Hyun Kim ◽  
Jin-Young Choi ◽  
Won-Ju Kim ◽  
Ji Yun Kim ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Germinal Center ◽  
Cell Activation ◽  
Helper T Cells ◽  
Follicular Helper T Cells ◽  
Follicular Helper ◽  
Germinal Center Formation

Lymphodepletion (LD), tumor-infiltrating lymphocytes (TIL) and high (HD-IL2) versus low-dose (LD-IL2) IL-2 followed by pembrolizumab (pembro) in patients (pts) with metastatic melanoma (MM).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 9543-9543
Author(s):  
Rodabe Navroze Amaria ◽  
Cara L. Haymaker ◽  
Marie-Andree Forget ◽  
Roland Bassett ◽  
Janice N. Cormier ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
Ex Vivo ◽  
Tumor Infiltrating Lymphocytes ◽  
Adoptive Cell Transfer ◽  
Unknown Primary ◽  
Prior Therapy ◽  
Md Anderson

9543 Background: TIL adoptive cell transfer (ACT) therapy can produce durable responses for MM pts although efficacy appears lower in the era of checkpoint inhibitors. Toxicities from HD-IL2, including sepsis physiology, limits widespread use of this regimen. Suppression of transferred TIL by either tumor cells or the tumor microenvironment could limit TIL responses. Pembro is known to promote T cell activation, thus, we evaluated the efficacy and safety of TIL with pembro with HD-IL2 versus LD-IL2. Methods: Pts with MM who had tumor harvested and cryopreserved TIL at MD Anderson with PS 0-1 and normal organ function were eligible. All pts received a standard LD regimen consisting of cyclophosphamide and fludarabine, followed by infusion of pooled ex-vivo expanded TIL and either HD-IL2 (Arm 1: 720,000 IU/kg IV q 8 hrs up to 15 doses) or LD-IL2 (Arm 2: 2 million IU SC for 14 d). Pts received pembro 200mg IV starting 21 d post T cell infusion every 3 wks for up to 2 yrs. Pts were randomized 1:1 based on stage and LDH. Paired blood and tumor biopsies were obtained prior to LD, prior to first and second dose of pembro and at time of progression. Results: A total of 36 pts were planned to enroll (18 in each arm); however, the protocol met pre-specified futility boundaries in Arm 1 which prompted early closure after treatment of 14 pts (7 in each Arm). Median age was 50 yrs, 6 were female, 8 had cutaneous melanoma, 2 mucosal, 2 uveal and 2 unknown primary. 86% were stage M1c, 14% M1D, 50% had LDH elevation. Median lines of prior therapy were 3 (range 1-6), including prior anti PD-1 in 13 pts. Best overall response was 1 PR (for 10 mos), 2 SD, 3 PD, 1 NE in Arm 1; 1 PR (ongoing over 36 mos), 1 SD, 5 PD in Arm 2. With median follow up of 9.2 mos, PFS was 3.9 mos for Arm 1 and 2.1 mos for Arm 2 (p = 0.99). Median OS was 9.7 mos for Arm 1 and 8.8 mos for Arm 2 (p = 0.71). Toxicity was similar in both Arms but with lower rates of grade 3 febrile neutropenia (57% vs. 71%) and shorter hospital stay (median 16 vs. 18 d) in Arm 2 vs. Arm 1. Conclusions: In a heavily treated pt population, TIL with pembro achieved low response rates. Use of LD-IL2 did not diminish efficacy and may be better tolerated than HD-IL2 for TIL ACT. Correlative studies are ongoing to determine mechanisms of treatment response and failure. Clinical trial information: NCT02500576.

scholarly journals The OX40/OX40L Axis Regulates T Follicular Helper Cell Differentiation: Implications for Autoimmune Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
NanNan Fu ◽  
Fang Xie ◽  
ZhongWen Sun ◽  
Qin Wang
Keyword(s):  
Cell Differentiation ◽  
Autoimmune Diseases ◽  
T Cell Activation ◽  
Cell Activation ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Close Relationship ◽  
Helper Function ◽  
T Follicular Helper Cell ◽  
And Function

T Follicular helper (Tfh) cells, a unique subset of CD4+ T cells, play an essential role in B cell development and the formation of germinal centers (GCs). Tfh differentiation depends on various factors including cytokines, transcription factors and multiple costimulatory molecules. Given that OX40 signaling is critical for costimulating T cell activation and function, its roles in regulating Tfh cells have attracted widespread attention. Recent data have shown that OX40/OX40L signaling can not only promote Tfh cell differentiation and maintain cell survival, but also enhance the helper function of Tfh for B cells. Moreover, upregulated OX40 signaling is related to abnormal Tfh activity that causes autoimmune diseases. This review describes the roles of OX40/OX40L in Tfh biology, including the mechanisms by which OX40 signaling regulates Tfh cell differentiation and functions, and their close relationship with autoimmune diseases.

scholarly journals T-cell agonists in cancer immunotherapy

2020 ◽  
Vol 8 (2) ◽  
pp. e000966
Author(s):  
Yeonjoo Choi ◽  
Yaoyao Shi ◽  
Cara L Haymaker ◽  
Aung Naing ◽  
Gennaro Ciliberto ◽  
...  
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Cell Function ◽  
Current Knowledge ◽  
Checkpoint Inhibitors ◽  
Costimulatory Molecules ◽  
The Body

Cancer cells can evade immune surveillance in the body. However, immune checkpoint inhibitors can interrupt this evasion and enhance the antitumor activity of T cells. Other mechanisms for promoting antitumor T-cell function are the targeting of costimulatory molecules expressed on the surface of T cells, such as 4-1BB, OX40, inducible T-cell costimulator and glucocorticoid-induced tumor necrosis factor receptor. In addition, CD40 targets the modulation of the activation of antigen-presenting cells, which ultimately leads to T-cell activation. Agonists of these costimulatory molecules have demonstrated promising results in preclinical and early-phase trials and are now being tested in ongoing clinical trials. In addition, researchers are conducting trials of combinations of such immune modulators with checkpoint blockade, radiotherapy and cytotoxic chemotherapeutic drugs in patients with advanced tumors. This review gives a comprehensive picture of the current knowledge of T-cell agonists based on their use in recent and ongoing clinical trials.

Restriction of PD-1 function by cis-PD-L1/CD80 interactions is required for optimal T cell responses

Science ◽  
2019 ◽  
Vol 364 (6440) ◽  
pp. 558-566 ◽  
Author(s):  
Daisuke Sugiura ◽  
Takumi Maruhashi ◽  
Il-mi Okazaki ◽  
Kenji Shimizu ◽  
Takeo K. Maeda ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
T Cell Responses ◽  
Cell Responses ◽  
Critical Components ◽  
Antigen Presenting ◽  
In Cis

Targeted blockade of PD-1 with immune checkpoint inhibitors can activate T cells to destroy tumors. PD-1 is believed to function mainly at the effector, but not in the activation, phase of T cell responses, yet how PD-1 function is restricted at the activation stage is currently unknown. Here we demonstrate that CD80 interacts with PD-L1 in cis on antigen-presenting cells (APCs) to disrupt PD-L1/PD-1 binding. Subsequently, PD-L1 cannot engage PD-1 to inhibit T cell activation when APCs express substantial amounts of CD80. In knock-in mice in which cis-PD-L1/CD80 interactions do not occur, tumor immunity and autoimmune responses were greatly attenuated by PD-1. These findings indicate that CD80 on APCs limits the PD-1 coinhibitory signal, while promoting CD28-mediated costimulation, and highlight critical components for induction of optimal immune responses.

scholarly journals Immunotherapy in hematologic malignancies

2019 ◽  
Vol 27 (S2) ◽  
Author(s):  
R.R. Kansara ◽  
C. Speziali
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
Cytotoxic T Cells ◽  
Hematologic Malignancies ◽  
Immune Checkpoints ◽  
Hematologic Neoplasms

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.

Novel synthetic immune modulators for the activation of tumor antigen-specific T cells.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15203-e15203
Author(s):  
Di Zhang ◽  
Lihua Shi ◽  
Susan Tam ◽  
Man-Cheong Fung
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Tumor Antigen ◽  
Cell Activation ◽  
Checkpoint Inhibitors ◽  
Adoptive T Cell Therapy ◽  
In Vivo Studies ◽  
Target Specificity ◽  
T Cell Therapy

e15203 Background: Although checkpoint inhibitor immunotherapy and adoptive T-cell therapy revolutionized cancer treatments, such approaches suffer either from lack of target specificity for checkpoint inhibitors or inability to target intracellular tumor-related antigens from CAR-T therapy. Here, we report the development of novel Tavo Immune Modulator (TIM) biologics molecules which can specifically recognize tumor antigen-specific T cells through an engineered pMHC complex with peptides derived from intracellular tumor-related antigens. These molecules can selectively activate such T cells through engineered T cell co-stimulatory modulators for enhanced tumor cell killing. Methods: NY-ESO-1 and MAGE-A10 TIM molecules were constructed as fusions of HLA-A*02:01 MHC complexed with either NY-ESO-1 (157-165) or MAGE-A10 (254-262) epitope peptides at the N-termini and various T cell costimulatory modulators at the C-termini of IgG heavy and light chains. TIM molecules were expressed in Expi293 cells and purified by Protein A affinity chromatography. Specific binding of TIM with cancer specific T cells was evaluated by immunostaining. The activation and proliferation of tumor specific CD8+ T cells were confirmed in T cell activation and recall assays. Results: Both NY-ESO-1 and MAGE-A10 specific TIM molecules were generated which recognized corresponding tumor specific T cells. NY-ESO-1 TIM engineered with IL2 could activate NY-ESO-1 specific CD8+ T cell exclusively. Engineering additional T cell costimulatory factors along with IL2 on NY-ESO-1 TIM molecule could further boost T cell proliferation and activation in T cell recall assays. Besides NY-ESO-1, combinations of T cell costimulatory factors with MAGE-A10 TIM molecules enhanced specific T cell activation. Additional in vitro and in vivo studies are ongoing to demonstrate efficacy of such novel TIM molecules in eliminating different types of NY-ESO-1 and MAGE-A10 which are over-expressed on tumor cells. Conclusions: This study demonstrates the utility of NY-ESO-1 and MAGE-A10 TIM molecules in the selective recognition and activation of tumor antigen-specific T cells. Such novel biologics molecules may provide target specificity in tumor treatment, and potential targeting of intracellular tumor-related antigens presented as peptides in MHC complexes on cell surfaces. Selective activation of tumor-specific T cells may provide a unique method for the treatment of various solid tumors and warrants further investigation.

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