scholarly journals Impairment of T cells' antiviral and anti-inflammation immunities may be critical to death from COVID-19

2021 ◽  
Vol 8 (12) ◽  
Author(s):  
Luhao Zhang ◽  
Rong Li ◽  
Gang Song ◽  
Gregory D. Scholes ◽  
Zhen-Su She
Keyword(s):  
T Cells ◽  
T Cell ◽  
Clinical Data ◽  
Inflammatory Responses ◽  
Dominant Role ◽  
Cell Number ◽  
Antiviral Responses ◽  
Virus Clearance ◽  
Cytokine Inhibition ◽  
Tissue Damages

Clarifying dominant factors determining the immune heterogeneity from non-survivors to survivors is crucial for developing therapeutics and vaccines against COVID-19. The main difficulty is quantitatively analysing the multi-level clinical data, including viral dynamics, immune response and tissue damages. Here, we adopt a top-down modelling approach to quantify key functional aspects and their dynamical interplay in the battle between the virus and the immune system, yielding an accurate description of real-time clinical data involving hundreds of patients for the first time. The quantification of antiviral responses gives that, compared to antibodies, T cells play a more dominant role in virus clearance, especially for mild patients (96.5%). Moreover, the anti-inflammatory responses, namely the cytokine inhibition and tissue repair rates, also positively correlate with T cell number and are significantly suppressed in non-survivors. Simulations show that the lack of T cells can lead to more significant inflammation, proposing an explanation for the monotonic increase of COVID-19 mortality with age and higher mortality for males. We propose that T cells play a crucial role in the immunity against COVID-19, which provides a new direction–improvement of T cell number for advancing current prevention and treatment.

scholarly journals Impairment of T cells’ antiviral and anti-inflammation immunities dominates the death from COVID-19

2021 ◽  
Author(s):  
Luhao Zhang ◽  
Rong Li ◽  
Gang Song ◽  
Gregory D. Scholes ◽  
Zhen-Su She
Keyword(s):  
T Cells ◽  
Clinical Data ◽  
Inflammatory Responses ◽  
Dominant Role ◽  
Cell Number ◽  
Immune Functions ◽  
Virus Clearance ◽  
Cytokine Inhibition ◽  
Tissue Damages ◽  
Positive Correlations

AbstractClarifying key factors dominating the immune heterogeneity from non-survivors to survivors is crucial for therapeutics and vaccine developments against COVID-19. The main difficulty is to quantitatively analyze the multi-level clinical data of viral dynamics, immune response, and tissue damages. Here, we adopt top-down modeling to quantify key functional aspects and their dynamical interplays in the virus-immune system battle, yielding an accurate description of real-time clinical data involving hundreds of patients for the first time. The quantification of antiviral responses demonstrates T cells’ dominant role in the virus clearance relative to antibodies, especially for mild patients (96.5%). Moreover, the anti-inflammatory responses, namely cytokine inhibition rate and tissue repair rate also have positive correlations with T cell number, and are significantly suppressed in non-survivors. Simulations show that impaired immune functions of T cells leads to greater inflammation (thus dominates the death), explaining the monotonous increase of COVID-19 mortality with age and higher mortality for males. We conclude that T cells play the role of crucial immunity that saves the death from COVID-19, which points out a new direction to advance current prevention and treatment by incorporating the vaccines, drugs and health care activities that aim to improve T cells’ number and functions.

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.

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 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 Neuropilin-1: a checkpoint target with unique implications for cancer immunology and immunotherapy

2020 ◽  
Vol 8 (2) ◽  
pp. e000967 ◽  
Author(s):  
Christopher A Chuckran ◽  
Chang Liu ◽  
Tullia C Bruno ◽  
Creg J Workman ◽  
Dario AA Vignali
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Modulation ◽  
Cell Function ◽  
Inflammatory Responses ◽  
Checkpoint Inhibitors ◽  
Objective Response ◽  
Standard Of Care ◽  
Peripheral Tolerance ◽  
Neuropilin 1

Checkpoint blockade immunotherapy established a new paradigm in cancer treatment: for certain patients curative treatment requires immune reinvigoration. Despite this monumental advance, only 20%–30% of patients achieve an objective response to standard of care immunotherapy, necessitating the consideration of alternative targets. Optimal strategies will not only stimulate CD8+ T cells, but concomitantly modulate immunosuppressive cells in the tumor microenvironment (TME), most notably regulatory T cells (Treg cells). In this context, the immunoregulatory receptor Neuropilin-1 (NRP1) is garnering renewed attention as it reinforces intratumoral Treg cell function amidst inflammation in the TME. Loss of NRP1 on Treg cells in mouse models restores antitumor immunity without sacrificing peripheral tolerance. Enrichment of NRP1+ Treg cells is observed in patients across multiple malignancies with cancer, both intratumorally and in peripheral sites. Thus, targeting NRP1 may safely undermine intratumoral Treg cell fitness, permitting enhanced inflammatory responses with existing immunotherapies. Furthermore, NRP1 has been recently found to modulate tumor-specific CD8+ T cell responses. Emerging data suggest that NRP1 restricts CD8+ T cell reinvigoration in response to checkpoint inhibitors, and more importantly, acts as a barrier to the long-term durability of CD8+ T cell-mediated tumor immunosurveillance. These novel and distinct regulatory mechanisms present an exciting therapeutic opportunity. This review will discuss the growing literature on NRP1-mediated immune modulation which provides a strong rationale for categorizing NRP1 as both a key checkpoint in the TME as well as an immunotherapeutic target with promise either alone or in combination with current standard of care therapeutic regimens.

scholarly journals Discovery Strategies to Maximize the Clinical Potential of T-Cell Engaging Antibodies for the Treatment of Solid Tumors

Antibodies ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Vladimir Voynov ◽  
Paul J. Adam ◽  
Andrew E. Nixon ◽  
Justin M. Scheer
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Cells ◽  
Clinical Data ◽  
Solid Tumor ◽  
Clinical Studies ◽  
Mode Of Action ◽  
Cytotoxic T Cells ◽  
Molecular Structures ◽  
Bispecific Antibodies

T-cell Engaging bispecific antibodies (TcEs) that can re-direct cytotoxic T-cells to kill cancer cells have been validated in clinical studies. To date, the clinical success with these agents has mainly been seen in hematologic tumor indications. However, an increasing number of TcEs are currently being developed to exploit the potent mode-of-action to treat solid tumor indications, which is more challenging in terms of tumor-cell accessibility and the complexity of the tumor microenvironment (TME). Of particular interest is the potential of TcEs as an immunotherapeutic approach for the treatment of non-immunogenic (often referred to as cold) tumors that do not respond to checkpoint inhibitors such as programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1) antibodies. This has led to considerable discovery efforts for, firstly, the identification of tumor selective targeting approaches that can safely re-direct cytotoxic T-cells to cancer cells, and, secondly, bispecific antibodies and their derivatives with drug-like properties that promote a potent cytolytic synapse between T-cells and tumor cells, and in the most advanced TcEs, have IgG-like pharmacokinetics for dosing convenience. Based on encouraging pre-clinical data, a growing number of TcEs against a broad range of targets, and using an array of different molecular structures have entered clinical studies for solid tumor indications, and the first clinical data is beginning to emerge. This review outlines the different approaches that have been taken to date in addressing the challenges of exploiting the TcE mode-of-action for a broad range of solid indications, as well as opportunities for future discovery potential.

scholarly journals Role of selenium-containing proteins in T-cell and macrophage function

2010 ◽  
Vol 69 (3) ◽  
pp. 300-310 ◽  
Author(s):  
Bradley A. Carlson ◽  
Min-Hyuk Yoo ◽  
Rajeev K. Shrimali ◽  
Robert Irons ◽  
Vadim N. Gladyshev ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Function ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Cell Receptor ◽  
Lymphoid Tissues ◽  
Protein Gel ◽  
Species Production

Selenium (Se) has been known for many years to have played a role in boosting the immune function, but the manner in which this element acts at the molecular level in host defence and inflammatory diseases is poorly understood. To elucidate the role of Se-containing proteins in the immune function, we knocked out the expression of this protein class in T-cells or macrophages of mice by targeting the removal of the selenocysteine tRNA gene using loxP-Cre technology. Mice with selenoprotein-less T-cells manifested reduced pools of mature and functional T-cells in lymphoid tissues and an impairment in T-cell-dependent antibody responses. Furthermore, selenoprotein deficiency in T-cells led to an inability of these cells to suppress reactive oxygen species production, which in turn affected their ability to proliferate in response to T-cell receptor stimulation. Selenoprotein-less macrophages, on the other hand, manifested mostly normal inflammatory responses, but this deficiency resulted in an altered regulation in extracellular matrix-related gene expression and a diminished migration of macrophages in a protein gel matrix. These observations provided novel insights into the role of selenoproteins in the immune function and tissue homeostasis.

scholarly journals Functional impairment of CD4 T cells despite normalization of T cell number in HIV

2006 ◽  
Vol 242 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Kenneth S. Knox ◽  
Richard B. Day ◽  
Lisa M. Kohli ◽  
Chadi A. Hage ◽  
Homer L. Twigg
Keyword(s):  
T Cells ◽  
T Cell ◽  
Functional Impairment ◽  
Cd4 T Cells ◽  
Cell Number

scholarly journals Early Induction of Interleukin-10 Limits Antigen-Specific CD4+T Cell Expansion, Function, and Secondary Recall Responses during Persistent Phagosomal Infection

2014 ◽  
Vol 82 (10) ◽  
pp. 4092-4103 ◽  
Author(s):  
Abinav Kumar Singh ◽  
Nagaraja R. Thirumalapura
Keyword(s):  
T Cells ◽  
T Cell ◽  
Functional Status ◽  
Persistent Infection ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Interleukin 10 ◽  
Host Cells ◽  
Content Type ◽  
Ifn Γ

ABSTRACTDiverse pathogens have evolved to survive and replicate in the endosomes or phagosomes of the host cells and establish persistent infection. Ehrlichiae are Gram-negative, intracellular bacteria that are transmitted by ticks. Ehrlichiae reside in the endosomes of the host phagocytic or endothelial cells and establish persistent infection in their vertebrate reservoir hosts. CD4+T cells play a critical role in protection against phagosomal infections. In the present study, we investigated the expansion, maintenance, and functional status of antigen-specific CD4+T cells during persistentEhrlichia murisinfection in wild-type and interleukin-10 (IL-10)-deficient mice. Our study indicated that early induction of IL-10 led to reduced inflammatory responses and impaired bacterial clearance during persistentEhrlichiainfection. Notably, we demonstrated that the functional production of gamma interferon (IFN-γ) by antigen-specific CD4+T cells maintained during a persistent phagosomal infection progressively deteriorates. The functional loss of IFN-γ production by antigen-specific CD4+T cells was reversed in the absence of IL-10. Furthermore, we demonstrated that transient blockade of IL-10 receptor during the T cell priming phase early in infection was sufficient to enhance the magnitude and the functional capacity of antigen-specific effector and memory CD4+T cells, which translated into an enhanced recall response. Our findings provide new insights into the functional status of antigen-specific CD4+T cells maintained during persistent phagosomal infection. The study supports the concept that a better understanding of the factors that influence the priming and differentiation of CD4+T cells may provide a basis to induce a protective immune response against persistent infections.

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