scholarly journals Binding of phosphatidylserine-positive microparticles by PBMCs classifies disease severity in COVID-19 patients

2021 ◽  
Author(s):  
Lisa Rausch ◽  
Konstantin Lutz ◽  
Martina Schifferer ◽  
Elena Winheim ◽  
Rudi Gruber ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Disease Severity ◽  
Inflammatory Responses ◽  
Immune Dysfunction ◽  
Coagulation Cascade ◽  
Activated Platelets ◽  
Programmed Death ◽  
Dying Cells ◽  
The Complement System

Infection with SARS-CoV-2 is associated with thromboinflammation, involving thrombotic and inflammatory responses, in many COVID-19 patients. In addition, immune dysfunction occurs in patients characterized by T cell exhaustion and severe lymphopenia. We investigated the distribution of phosphatidylserine (PS), a marker of dying cells, activated platelets, and platelet-derived microparticles (PMP), during the clinical course of COVID-19. We found an unexpectedly high amount of blood cells loaded with PS+ PMPs for weeks after the initial COVID-19 diagnosis. Elevated frequencies of PS+PMP+ PBMCs correlated strongly with increasing disease severity. As a marker, PS outperformed established laboratory markers for inflammation, leucocyte composition, and coagulation, currently used for COVID-19 clinical outcome prognosis. PS+ PMPs preferentially bound to CD8+ T cells with gene expression signatures of proliferating effector rather than memory T cells. As PS+ PMPs carried programmed death-ligand 1 (PD-L1), they may affect T cell expansion or function. Our data provide a novel marker for disease severity and show that PS, which can trigger the blood coagulation cascade, the complement system, and inflammation, resides on activated immune cells. Therefore, PS may serve as a beacon to attract thromboinflammatory processes toward lymphocytes and cause immune dysfunction in COVID-19.

scholarly journals CD40/CD40L contributes to hypercholesterolemia-induced microvascular inflammation

2009 ◽  
Vol 296 (3) ◽  
pp. H689-H697 ◽  
Author(s):  
Karen Y. Stokes ◽  
LeShanna Calahan ◽  
Candiss M. Hamric ◽  
Janice M. Russell ◽  
D. Neil Granger
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
T Cell ◽  
Blood Cell ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Microvascular Dysfunction ◽  
Cd40 Ligand ◽  
Scid Mice ◽  
Endothelial Cell Function

Hypercholesterolemia is associated with phenotypic changes in endothelial cell function that lead to a proinflammatory and prothrombogenic state in different segments of the microvasculature. CD40 ligand (CD40L) and its receptor CD40 are ubiquitously expressed and mediate inflammatory responses and platelet activation. The objective of this study was to determine whether CD40/CD40L, in particular T-cell CD40L, contributes to microvascular dysfunction induced by hypercholesterolemia. Intravital microscopy was used to quantify blood cell adhesion in cremasteric postcapillary venules, endothelium-dependent vasodilation responses in arterioles, and microvascular oxidative stress in wild-type (WT) C57BL/6, CD40-deficient (−/−), CD40L−/−, or severe combined immune deficient (SCID) mice placed on a normal (ND) or high-cholesterol (HC) diet for 2 wk. WT-HC mice exhibited an exaggerated leukocyte and platelet recruitment in venules and impaired vasodilation responses in arterioles compared with ND counterparts. A deficiency of CD40, CD40L, or lymphocytes attenuated these responses to HC. The HC phenotype was rescued in CD40L−/− and SCID mice by a transfer of WT T cells. Bone marrow chimeras revealed roles for both vascular- and blood cell-derived CD40 and CD40L in the HC-induced vascular responses. Hypercholesterolemia induced an oxidative stress in both arterioles and venules of WT mice, which was abrogated by either CD40 or CD40L deficiency. The transfer of WT T cells into CD40L−/− mice restored the oxidative stress. These results implicate CD40/CD40L interactions between circulating cells and the vascular wall in both the arteriolar and venular dysfunction elicited by hypercholesterolemia and identify T-cell-associated CD40L as a key mediator of these responses.

scholarly journals Relationship between PD-L1 expression, CD8+ T-cell infiltration and prognosis in intrahepatic cholangiocarcinoma patients

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Min Deng ◽  
Shao-Hua Li ◽  
Xu Fu ◽  
Xiao-Peng Yan ◽  
Jun Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Intrahepatic Cholangiocarcinoma ◽  
Patient Survival ◽  
Disease Free Survival ◽  
Cd8 T Cell ◽  
Future Research ◽  
Programmed Death ◽  
Expression Rate

Abstract Background Programmed death- ligand 1 (PD-L1) seems to be associated with the immune escape of tumors, and immunotherapy may be a favorable treatment for PD-L1-positive patients. We evaluated intrahepatic cholangiocarcinoma (ICC) specimens for their expression of PD-L1, infiltration of CD8+ T cells, and the relationship between these factors and patient survival. Methods In total, 69 resections of ICC were stained by immunohistochemistry for PD-L1, programmed death factor-1 (PD-1), and CD8+ T cells. CD8+ T-cell densities were analyzed both within tumors and at the tumor-stromal interface. Patient survival was predicted based on the PD-L1 status and CD8+ T-cell density. Results The expression rate of PD-L1 was 12% in cancer cells and 51% in interstitial cells. The expression rate of PD-1 was 30%, and the number of CD8+ T-cells increased with the increase of PD-L1 expression (p < 0.05). The expression of PD-L1 in the tumor was correlated with poor overall survival(OS) (p = 0.004), and the number of tumor and interstitial CD8+ T-cells was correlated with poor OS and disease-free survival (DFS) (All p < 0.001). Conclusions The expression of PD-L1 in the tumor is related to poor OS, and the number of tumor or interstitial CD8+ T-cells is related to poor OS and DFS. For patients who lose their chance of surgery, PD-L1 immunosuppressive therapy may be the focus of future research as a potential treatment.

Enhanced Infiltration of Central Memory T Cells to the Lung Tissue during Allergic Lung Inflammation

2021 ◽  
pp. 1-15
Author(s):  
Mashael Alabed ◽  
Asma Sultana Shaik ◽  
Narjes Saheb Sharif-Askari ◽  
Fatemeh Saheb Sharif-Askari ◽  
Shirin Hafezi ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lung Tissue ◽  
Lung Inflammation ◽  
Inflammatory Responses ◽  
Memory T Cells ◽  
Central Memory ◽  
Effector Memory ◽  
Differential Distribution ◽  
Allergic Lung Inflammation

Memory T cells play a central role in regulating inflammatory responses during asthma. However, tissue distribution of effector memory (T<sub>EM</sub>) and central memory (T<sub>CM</sub>) T-cell subtypes, their differentiation, and their contribution to the persistence of lung tissue inflammation during asthma are not well understood. Interestingly, an increase in survival and persistence of memory T cells was reported in asthmatic lungs, which may suggest a shift toward the more persistent T<sub>CM</sub> phenotype. In this report, we investigated the differential distribution of memory T-cell subtypes during allergic lung inflammation and the mechanism regulating that. Using an OVA-sensitized asthma mouse model, we observed a significant increase in the frequency of T<sub>CM</sub> cells in inflamed lungs compared to healthy controls. Interestingly, adoptive transfer techniques confirmed substantial infiltration of T<sub>CM</sub> cells to lung tissues during allergic airway inflammation. Expression levels of T<sub>CM</sub> homing receptors, CD34 and GlyCAM-1, were also significantly upregulated in the lung tissues of OVA-sensitized mice, which may facilitate the increased T<sub>CM</sub> infiltration into inflamed lungs. Moreover, a substantial increase in the relative expression of T<sub>CM</sub> profile-associated genes (EOMES, BCL-6, ID3, TCF-7, BCL-2, BIM, and BMI-1) was noted for T<sub>EM</sub> cells during lung inflammation, suggesting a shift for T<sub>EM</sub> into the T<sub>CM</sub> state. To our knowledge, this is the first study to report an increased infiltration of T<sub>CM</sub> cells into inflamed lung tissues and to suggest differentiation of T<sub>EM</sub> to T<sub>CM</sub> cells in these tissues. Therapeutic interference at T<sub>CM</sub> infiltration or differentiations could constitute an alternative treatment approach for lung inflammation.

scholarly journals PD-1 dependent expansion of Amphregulin+FOXP3+ cells is associated with oral immune dysfunction in HIV patients on therapy

2021 ◽  
Author(s):  
N Bhaskaran ◽  
E Schneider ◽  
F Faddoul ◽  
A Paes da Silva ◽  
R Asaad ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Oral Mucosa ◽  
Immune Dysfunction ◽  
People Living With Hiv ◽  
Dependent Manner ◽  
Mucosal Tissues ◽  
T Cell Regulation ◽  
Ifn Γ

AbstractResidual systemic inflammation and mucosal immune dysfunction persist in people living with HIV (PLWH) despite treatment with combined anti-retroviral therapy (cART), but the underlying immune mechanisms are poorly understood. Here we report an altered immune landscape involving upregulation of TLR- and inflammasome signaling, localized CD4+ T cell hyperactivation, and counterintuitively, an enrichment of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in the oral mucosa of HIV+ patients on therapy. Using human oral tonsil cultures, we found that HIV infection causes an increase in a unique population of FOXP3+ cells expressing PD-1, IFN-γ, Amphiregulin (AREG), and IL-10. These cells persisted even in the presence of the anti-retroviral drug and underwent further expansion driven by TLR-2 ligands and IL-1β. IL-1β also promoted PD-1 upregulation in AKT1 dependent manner. PD-1 stabilized FOXP3 and AREG expression in these cells through a mechanism requiring the activation of Asparaginyl Endopeptidase (AEP). Importantly, these FOXP3+ cells were incapable of suppressing CD4+ T cells in vitro. Concurrently, HIV+ patients harbored higher levels of PD-1, IFN-γ, Amphiregulin (AREG), and IL-10 expressing FOXP3+ cells, which strongly correlated with CD4+ T cell hyperactivation, suggesting an absence of CD4+ T cell regulation in the oral mucosa. Taken together, this study provides insights into a novel mechanism of FOXP3+ cell dysregulation and reveals a critical link in the positive feedback loop of oral mucosal immune activation events in HIV+ patients on therapy.One Sentence SummaryHIV-induced immune dysfunction in lymphoid and mucosal tissues

scholarly journals Prolonged activation of nasal immune cell populations and development of tissue-resident SARS-CoV-2 specific CD8 T cell responses following COVID-19

2021 ◽  
Author(s):  
Anna H.E. Roukens ◽  
Marion König ◽  
Tim Dalebout ◽  
Tamar Tak ◽  
Shohreh Azimi ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
T Cell ◽  
Nasal Mucosa ◽  
Immune Cell ◽  
Inflammatory Responses ◽  
Upper Airway ◽  
Effector Memory ◽  
Long Term Effects ◽  
Activated T Cells

AbstractThe immune system plays a major role in Coronavirus Disease 2019 (COVID-19) pathogenesis, viral clearance and protection against re-infection. Immune cell dynamics during COVID-19 have been extensively documented in peripheral blood, but remain elusive in the respiratory tract. We performed minimally-invasive nasal curettage and mass cytometry to characterize nasal immune cells of COVID-19 patients during and 5-6 weeks after hospitalization. Contrary to observations in blood, no general T cell depletion at the nasal mucosa could be detected. Instead, we observed increased numbers of nasal granulocytes, monocytes, CD11c+ NK cells and exhausted CD4+ T effector memory cells during acute COVID-19 compared to age-matched healthy controls. These pro-inflammatory responses were found associated with viral load, while neutrophils also negatively correlated with oxygen saturation levels. Cell numbers mostly normalized following convalescence, except for persisting CD127+ granulocytes and activated T cells, including CD38+ CD8+ tissue-resident memory T cells. Moreover, we identified SARS-CoV-2 specific CD8+ T cells in the nasal mucosa in convalescent patients. Thus, COVID-19 has both transient and long-term effects on the immune system in the upper airway.

scholarly journals Checkpoint Blockade in Combination with CD33 Chimeric Antigen Receptor T Cell Therapy and Hypomethylating Agent Against Acute Myeloid Leukemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1383-1383 ◽  
Author(s):  
Tongyuan Xue ◽  
Marissa Del Real ◽  
Emanuela Marcucci ◽  
Candida Toribio ◽  
Sonia Maryam Setayesh ◽  
...  
Keyword(s):  
T Cells ◽  
Acute Myeloid Leukemia ◽  
T Cell ◽  
Myeloid Leukemia ◽  
T Cell Therapy ◽  
Programmed Death ◽  
Car T ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. The cure rate for primary AML patients is only 35% and decreases with age. Novel and effective immunotherapies for patients with relapsed and/or refractory (r/r) AML remain an urgent unmet need. CD33 is an attractive immunotherapeutic target for myeloid malignancies given its expression on more than 85% of AML patient samples. We therefore set out to design and test CD33 chimeric antigen receptor (CD33CAR) T cells preclinically as a single agent and in combinational therapy. To assess antileukemic responses of CD33CAR T cells in vitro and in vivo, we enriched CD4/CD8 T cells from peripheral blood mononuclear cells (PBMCs) and genetically modified them to express a second-generation CD33CAR. CD33CAR T cells exhibited potent antigen dependent CD107a degranulation, IFN-γ production and killing activities against AML cells in vitro. Using a NOD-SCID-IL2Rgnull (NSG) xenograft model engrafted with MOLM-14-ffluc, a CD33 expressing AML cell line transduced with lentivirus carrying firefly luciferase (ffluc) and enhanced green fluorescent protein (eGFP), 3 million CD33CAR or mock T cells were introduced intravenously. CD33 CAR T cell-treated group displayed 98.2% leukemic regression 4 days post CAR T infusion, and 99.6% reduction on day 31. Bioluminescent imaging (BLI) and Kaplan-Meier analysis demonstrated that CD33CAR T cells significantly decreased leukemic burden and prolonged overall survival compared to mock T cells in vivo. Decitabine, a DNA hypomethylating agent (HMA), is a main therapeutic agent for treating AML. We observed HMA treatment led to increased CD33 expression on MOLM-14 cells in vitro. We hypothesized that decitabine can potentiate CD33CAR T cell-mediated AML killing by increasing CD33 expression. MOLM-14 cells were treated with either decitabine alone, CD33CAR T cells alone, or sequential treatment using various concentrations of decitabine or DMSO followed by CD33CAR or mock T cells in an E:T ratio of 1:100. We determined the target specific killing activities in each group using flow cytometric based analysis 48 and 96 hours later. The decitabine followed by CD33CAR T cells treatment reproducibly resulted in the most robust antileukemic activity with 80.6% MOLM-14 cells killed. In comparison, CD33CAR T cells or decitabine monotherapy resulted in 11.5% and 50.9% killing, respectively. In vivo testing of the combinational effects of decitabine and CD33CAR T cells are underway and will be updated at the meeting. Finally, checkpoint blockade targeting programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) has shown survival benefits, particularly in combination with HMA, for patients with r/r AML (Daver et al. 2019). We observed elevated PD-L1 expression on residual AML blasts that survived the treatment with decitabine in combination with CD33CAR T cells. Therefore, we hypothesized that blockade of PD-1/PD-L1 interaction might further improve the antileukemic effect of CD33CAR T cells against AML cells post antigen induction by decitabine. MOLM-14 cells were treated with decitabine for 2 days and CD33CAR T cells were added in an E:T ratio of 1:75. Anti-PD-1 or IgG4 antibody was added to the culture at various concentrations. The most robust CD33 specific killing was seen in the culture with anti-PD-1 antibody added. Further characterization are underway and will be presented. Taken together, our preclinical findings have demonstrated the potency of the CD33CAR T cell therapy and ways to optimize its efficacy. Our results support clinical translation of CD33CAR T cells for patients with AML. Disclosures Budde: F. Hoffmann-La Roche Ltd: Consultancy.

Differentiated activity profile for the PD-1 inhibitor balstilimab.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5529-5529
Author(s):  
Cailin Joyce ◽  
Dhan Chand ◽  
Benjamin Duckless ◽  
Manuel Hidalgo ◽  
Joseph Elan Grossman ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
T Cells ◽  
T Cell ◽  
Cancer Cells ◽  
Culture System ◽  
Checkpoint Inhibitors ◽  
Objective Response ◽  
Activity Profile ◽  
Double Positive ◽  
Programmed Death

5529 Background: The development and clinical application of immune checkpoint inhibitors has transformed the therapeutic landscape for cancer treatment in recent years. Balstilimab (AGEN2034) is a fully human, monoclonal IgG4 antibody that binds with high affinity to programmed death 1 (PD-1), thus preventing the interaction between this receptor and its ligands programmed death ligand 1 and 2 (PD-L1, PD-L2). Emerging evidence suggests that balstilimab exhibits a differentiated activity profile compared to currently approved anti-PD-1 agents, including pembrolizumab and nivolumab. Methods: Balstilimab as monotherapy was evaluated in a large phase 2 study in patients (pts) with recurrent/metastatic cervical cancer who had relapsed after a platinum-based treatment regimen for advanced disease. Pts were dosed at 3 mg/kg once every 2 weeks for up to 24 months and antitumor activity was assessed using RECIST v1.1. The tumor cell killing activity of balstilimab was evaluated preclinically in a human co-culture system of (1) primary T cells engineered to recognize NY-ESO-1 and (2) NY-ESO-1+ cancer cell lines, including PD-L1 and/or PD-L2-deficient engineered lines. The co-culture system was maintained for ̃ two weeks to drive partial T cell exhaustion; a state where cytotoxicity is compromised but recoverable with PD-1 blockade. Cytotoxicity of these partially exhausted T cells was quantified against PD-L1/L2 double positive, single positive, or double negative cancer cells in the presence or absence of PD-(L)1 antibodies. Results: In the second-line treatment setting for pts with advanced cervical cancer, balstilimab showed a numerically higher objective response rate (ORR) in subjects with PD-L1+, squamous cell carcinoma (SCC) tumors (21%, 95% CI, 12.7-32.6%) than those reported for pembrolizumab. Unlike pembrolizumab, balstilimab showed activity in PD-L1(-) pts, and irrespective of tumor histology (ORR 7.9%, 95% CI, 2.7-20.8%). Despite lower overall PD-L1 positivity compared to SCC (41.7 v 72.9%), an ORR of 12.5% (95% CI, 5.9-24.7%) was observed in the subset of pts with a poorer prognosis, those with cervical adenocarcinoma. Concordant with clinical observations, balstilimab demonstrated superior rescue of antigen-specific T cell cytotoxicity in vitro relative to pembrolizumab, nivolumab, or atezolizumab. Balstilimab also induced cytotoxicity against PD-L1 and/or PD-L2 deficient target cancer cells. Conclusions: Taken together, these data suggest functional differentiation of balstilimab from other PD-1 inhibitors with potentially important implications for extending the therapeutic reach of anti-PD-1 therapy. Investigation of the underlying mechanistic basis for these findings is ongoing. Clinical trial information: NCT03104699.

The complement system

2010 ◽  
pp. 213-224
Author(s):  
Marina Botto ◽  
Mark J. Walport
Keyword(s):  
Immune System ◽  
Complement System ◽  
Immune Complexes ◽  
Innate Immune System ◽  
Inflammatory Responses ◽  
Antibody Responses ◽  
Host Defence ◽  
System P ◽  
Dying Cells ◽  
The Complement System

The complement system consists of over 20 distinct proteins and is an essential component of the innate immune system. It is a major effector mechanism of host defence against infection and inflammatory responses, has an important role in the physiological removal of immune complexes and dying cells, and plays an accessory role in the induction of antibody responses....

scholarly journals Review of Indications of FDA-Approved Immune Checkpoint Inhibitors per NCCN Guidelines with the Level of Evidence

Cancers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 738 ◽  
Author(s):  
Raju K. Vaddepally ◽  
Prakash Kharel ◽  
Ramesh Pandey ◽  
Rohan Garje ◽  
Abhinav B. Chandra
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Molecular Mechanisms ◽  
Checkpoint Inhibitors ◽  
Hematopoietic Cells ◽  
Fda Approval ◽  
Programmed Death ◽  
Cancerous Cells

Cancer is associated with higher morbidity and mortality and is the second leading cause of death in the US. Further, in some nations, cancer has overtaken heart disease as the leading cause of mortality. Identification of molecular mechanisms by which cancerous cells evade T cell-mediated cytotoxic damage has led to the modern era of immunotherapy in cancer treatment. Agents that release these immune brakes have shown activity to recover dysfunctional T cells and regress various cancer. Both cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and Programmed Death-1 (PD-1) play their role as physiologic brakes on unrestrained cytotoxic T effector function. CTLA-4 (CD 152) is a B7/CD28 family; it mediates immunosuppression by indirectly diminishing signaling through the co-stimulatory receptor CD28. Ipilimumab is the first and only FDA-approved CTLA-4 inhibitor; PD-1 is an inhibitory transmembrane protein expressed on T cells, B cells, Natural Killer cells (NKs), and Myeloid-Derived Suppressor Cells (MDSCs). Programmed Death-Ligand 1 (PD-L1) is expressed on the surface of multiple tissue types, including many tumor cells and hematopoietic cells. PD-L2 is more restricted to hematopoietic cells. Blockade of the PD-1 /PDL-1 pathway can enhance anti-tumor T cell reactivity and promotes immune control over the cancerous cells. Since the FDA approval of ipilimumab (human IgG1 k anti-CTLA-4 monoclonal antibody) in 2011, six more immune checkpoint inhibitors (ICIs) have been approved for cancer therapy. PD-1 inhibitors nivolumab, pembrolizumab, cemiplimab and PD-L1 inhibitors atezolizumab, avelumab, and durvalumab are in the current list of the approved agents in addition to ipilimumab. In this review paper, we discuss the role of each immune checkpoint inhibitor (ICI), the landmark trials which led to their FDA approval, and the strength of the evidence per National Comprehensive Cancer Network (NCCN), which is broadly utilized by medical oncologists and hematologists in their daily practice.

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