scholarly journals Brd4 Regulates the Homeostasis of CD8+ T-Lymphocytes and Their Proliferation in Response to Antigen Stimulation

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhilin Peng ◽  
Yiwen Zhang ◽  
Xiancai Ma ◽  
Mo Zhou ◽  
Shiyu Wu ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
T Cell Response ◽  
Cell Immune Response ◽  
Type I ◽  
T Cell Homeostasis ◽  
Cell Homeostasis ◽  
Antigen Stimulation

CD8+ T cells are major components of adaptive immunity and confer robust protective cellular immunity, which requires adequate T-cell numbers, targeted migration, and efficient T-cell proliferation. Altered CD8+ T-cell homeostasis and impaired proliferation result in dysfunctional immune response to infection or tumorigenesis. However, intrinsic factors controlling CD8+ T-cell homeostasis and immunity remain largely elusive. Here, we demonstrate the prominent role of Brd4 on CD8+ T cell homeostasis and immune response. By upregulating Myc and GLUT1 expression, Brd4 facilitates glucose uptake and energy production in mitochondria, subsequently supporting naïve CD8+ T-cell survival. Besides, Brd4 promotes the trafficking of naïve CD8+ T cells partially through maintaining the expression of homing receptors (CD62L and LFA-1). Furthermore, Brd4 is required for CD8+ T cell response to antigen stimulation, as Brd4 deficiency leads to a severe defect in clonal expansion and terminal differentiation by decreasing glycolysis. Importantly, as JQ1, a pan-BRD inhibitor, severely dampens CD8+ T-cell immune response, its usage as an anti-tumor agent or latency-reversing agent for human immunodeficiency virus type I (HIV-1) should be more cautious. Collectively, our study identifies a previously-unexpected role of Brd4 in the metabolic regulation of CD8+ T cell-mediated immune surveillance and also provides a potential immunomodulation target.

scholarly journals A possible role of immunopathogenesis in COVID-19 progression

2020 ◽  
Author(s):  
Moritz Anft ◽  
Krystallenia Paniskaki ◽  
Arturo Blazquez-Navarro ◽  
Adrian Doevelaar ◽  
Felix S. Seibert ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Humoral Immunity ◽  
Viral Infections ◽  
Cell Subset ◽  
T Cell Response ◽  
T Cell Subsets ◽  
Clear Correlation

AbstractBackgroundThe efficacy of the humoral and cellular immunity determines the outcome of viral infections. An appropriate immune response mediates protection, whereas an overwhelming immune response has been associated with immune-mediated pathogenesis in viral infections. The current study explored the general and SARS-CoV-2 specific cellular and humoral immune status in patients with different COVID-19 severities.MethodsIn this prospective study, we included 53 patients with moderate, severe, and critical COVID-19 manifestations comparing their quantitative, phenotypic, and functional characteristics of circulating immune cells, SARS-CoV-2 antigen specific T-cells, and humoral immunity.ResultsSignificantly diminished frequencies of CD8+T-cells, CD4+ and CD8+T-cell subsets with activated differentiated memory/effector phenotype and migratory capacity were found in circulation in patients with severe and/or critical COVID-19 as compared to patients with moderate disease. Importantly, the improvement of the clinical courses from severe to moderate was accompanied by an improvement in the T-cell subset alterations. Furthermore, we surprisingly observed a detectable SARS-CoV-2-reactive T-cell response in all three groups after stimulation with SARS-CoV-2 S-protein overlapping peptide pool already at the first visit. Of note, patients with a critical COVID-19 demonstrated a stronger response of SARS-CoV-2-reactive T-cells producing Th1 associated inflammatory cytokines. Furthermore, clear correlation between antibody titers and SARS-CoV-2-reactive CD4+ frequencies underscore the role of specific immunity in disease progression.ConclusionOur data demonstrate that depletion of activated memory phenotype circulating T-cells and a strong SARS-CoV-2-specific cellular and humoral immunity are associated with COVID-19 disease severity. This counter-intuitive finding may have important implications for diagnostic, therapeutic and prophylactic COVID-19 management.

scholarly journals The Cytomegalovirus-Specific CD4+ T-Cell Response Expands with Age and Markedly Alters the CD4+ T-Cell Repertoire

2007 ◽  
Vol 81 (14) ◽  
pp. 7759-7765 ◽  
Author(s):  
Batoul Pourgheysari ◽  
Naeem Khan ◽  
Donna Best ◽  
Rachel Bruton ◽  
Laxman Nayak ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cell Response ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Cell Immune Response ◽  
T Cell Repertoire ◽  
Immune Senescence ◽  
Cell Repertoire

ABSTRACT Immune function in the elderly is associated with a number of phenotypic and functional abnormalities, and this phenomenon of immune senescence is associated with increased susceptibility to infection. The immune response to pathogens frequently declines with age, but the CD8+ T-cell response to cytomegalovirus (CMV) is unusual, as it demonstrates a significant expansion over time. Here we have documented the CD4+ T-cell immune response to CMV in healthy donors of different ages. The magnitude of the CMV-specific CD4+ T-cell immune response increases from a mean of 2.2% of the CD4+ T-cell pool in donors below 50 years of age to 4.7% in donors aged over 65 years. In addition, CMV-specific CD4+ T cells in elderly donors demonstrate decreased production of interleukin-2 and less dependence on costimulation. CMV seropositivity is associated with marked changes in the phenotype of the overall CD4+ T-cell repertoire in healthy aged donors, including an increase in CD57+ expression and a decrease in CD28 and CD27 expression, a phenotypic profile characteristic of immune senescence. This memory inflation of CMV-specific CD4+ T cells contributes to evidence that CMV infection may be damaging to immune function in elderly individuals.

scholarly journals Role of Direct Effects of IFN-γ on T Cells in the Regulation of CD8 T Cell Homeostasis

2007 ◽  
Vol 179 (4) ◽  
pp. 2115-2125 ◽  
Author(s):  
Kavita Tewari ◽  
Yumi Nakayama ◽  
M. Suresh
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cell ◽  
Direct Effects ◽  
T Cell Homeostasis ◽  
Cell Homeostasis ◽  
Ifn Γ

scholarly journals Immunosequencing and epitope mapping reveal substantial preservation of the T cell immune response to Omicron generated by SARS-CoV-2 vaccines

2021 ◽  
Author(s):  
Damon H. May ◽  
Benjamin E. R. Rubin ◽  
Sudeb C. Dalai ◽  
Krishna Patel ◽  
Shahin Shafiani ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cellular Immune Response ◽  
Epitope Mapping ◽  
Protective Efficacy ◽  
T Cell Response ◽  
Cell Immune Response ◽  
Cell Immunity ◽  
Cellular Immune

The Omicron SARS-CoV-2 variant contains 34 mutations in the spike gene likely impacting protective efficacy from vaccines. We evaluated the potential impact of these mutations on the cellular immune response. Combining epitope mapping to SARS-CoV-2 vaccines that we have determined from past experiments along with T cell receptor (TCR) repertoire sequencing from thousands of vaccinated or naturally infected individuals, we estimate the abrogation of the cellular immune response in Omicron. Although 20% of CD4+ T cell epitopes are potentially affected, the loss of immunity mediated by CD4+ T cells is estimated to be slightly above 30% as some of the affected epitopes are relatively more immunogenic. For CD8+ T cells, we estimate a loss of approximately 20%. These reductions in T cell immunity are substantially larger than observed in other widely distributed variants. Combined with the expected substantial loss of neutralization from antibodies, the overall protection provided by SARS-CoV-2 vaccines could be impacted adversely. From analysis of prior variants, the efficacy of vaccines against symptomatic infection has been largely maintained and is strongly correlated with the T cell response but not as strongly with the neutralizing antibody response. We expect the remaining 70% to 80% of on-target T cells induced by SARS-CoV-2 vaccination to reduce morbidity and mortality from infection with Omicron.

scholarly journals Vaccination and Infection of Swine With Salmonella Typhimurium Induces a Systemic and Local Multifunctional CD4+ T-Cell Response

2021 ◽  
Vol 11 ◽  
Author(s):  
Selma Schmidt ◽  
Elena L. Sassu ◽  
Eleni Vatzia ◽  
Alix Pierron ◽  
Julia Lagler ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
T Cell Response ◽  
Effector Memory ◽  
Cell Immune Response ◽  
Control Group ◽  
Tnf Α ◽  
Ifn Γ

The gram-negative facultative intracellular bacteria Salmonella Typhimurium (STM) often leads to subclinical infections in pigs, but can also cause severe enterocolitis in this species. Due to its high zoonotic potential, the pathogen is likewise dangerous for humans. Vaccination with a live attenuated STM strain (Salmoporc) is regarded as an effective method to control STM infections in affected pig herds. However, information on the cellular immune response of swine against STM is still scarce. In this study, we investigated the T-cell immune response in pigs that were vaccinated twice with Salmoporc followed by a challenge infection with a virulent STM strain. Blood- and organ-derived lymphocytes (spleen, tonsils, jejunal and ileocolic lymph nodes, jejunum, ileum) were stimulated in vitro with heat-inactivated STM. Subsequently, CD4+ T cells present in these cell preparations were analyzed for the production of IFN-γ, TNF-α, and IL-17A by flow cytometry and Boolean gating. Highest frequencies of STM-specific cytokine-producing CD4+ T cells were found in lamina propria lymphocytes of jejunum and ileum. Significant differences of the relative abundance of cytokine-producing phenotypes between control group and vaccinated + infected animals were detected in most organs, but dominated in gut and lymph node-residing CD4+ T cells. IL-17A producing CD4+ T cells dominated in gut and gut-draining lymph nodes, whereas IFN-γ/TNF-α co-producing CD4+ T cells were present in all locations. Additionally, the majority of cytokine-producing CD4+ T cells had a CD8α+CD27- phenotype, indicative of a late effector or effector memory stage of differentiation. In summary, we show that Salmonella-specific multifunctional CD4+ T cells exist in vaccinated and infected pigs, dominate in the gut and most likely contribute to protective immunity against STM in the pig.

scholarly journals CD8+ T Cell Immune Response in Immunocompetent Mice during Zika Virus Infection

2017 ◽  
Vol 91 (22) ◽  
Author(s):  
Huarong Huang ◽  
Shihua Li ◽  
Yongli Zhang ◽  
Xiaojuan Han ◽  
Baoqian Jia ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Virus Infection ◽  
Immune Responses ◽  
Zika Virus ◽  
Cell Response ◽  
T Cell Response ◽  
Cell Immune Response ◽  
Zikv Infection

ABSTRACT Zika virus (ZIKV) infection causees neurologic complications, including Guillain-Barré syndrome in adults and central nervous system (CNS) abnormalities in fetuses. We investigated the immune response, especially the CD8+ T cell response in C57BL/6 (B6) wild-type (WT) mice, during ZIKV infection. We found that a robust CD8+ T cell response was elicited, major histocompatibility complex class I-restricted CD8+ T cell epitopes were identified, a tetramer that recognizes ZIKV-specific CD8+ T cells was developed, and virus-specific memory CD8+ T cells were generated in these mice. The CD8+ T cells from these infected mice were functional, as evidenced by the fact that the adoptive transfer of ZIKV-specific CD8+ T cells could prevent ZIKV infection in the CNS and was cross protective against dengue virus infection. Our findings provide comprehensive insight into immune responses against ZIKV and further demonstrate that WT mice could be a natural and easy-access model for evaluating immune responses to ZIKV infection. IMPORTANCE ZIKV infection has severe clinical consequences, including Guillain-Barré syndrome in adults, microcephaly, and congenital malformations in fetuses and newborn infants. Therefore, study of the immune response, especially the adaptive immune response to ZIKV infection, is important for understanding diseases caused by ZIKV infection. Here, we characterized the CD8+ T cell immune response to ZIKV in a comprehensive manner and identified ZIKV epitopes. Using the identified immunodominant epitopes, we developed a tetramer that recognizes ZIKV-specific CD8+ T cells in vivo, which simplified the detection and evaluation of ZIKV-specific immune responses. In addition, the finding that tetramer-positive memory CD8+ T cell responses were generated and that CD8+ T cells can traffic to a ZIKV-infected brain greatly enhances our understanding of ZIKV infection and provides important insights for ZIKV vaccine design.

scholarly journals β-Glucan Oligosaccharide EnhancesCD8+T Cells Immune Response Induced by a DNA Vaccine Encoding Hepatitis B Virus Core Antigen

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Jing Wang ◽  
Shengfu Dong ◽  
Chunhong Liu ◽  
Wei Wang ◽  
Shuhui Sun ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Dna Vaccine ◽  
Dna Vaccination ◽  
T Cell Response ◽  
Basic Unit ◽  
Cell Immune Response ◽  
Core Antigen ◽  
Human Beings

DNA vaccination can induce specificCD8+T cell immune response, but the response level is low in large mammals and human beings. Coadministration of an adjuvant can optimize protective immunity elicited by a DNA vaccine. In this study, we investigated the effect of a synthetic glucohexaose (β-glu6), an analogue of Lentinan basic unit, on specificCD8+T cell response induced by a DNA vaccine encoding HBcAg (pB144) in mice. We found thatβ-glu6 promoted the recruitment and maturation of dendritic cells, enhanced the activation ofCD8+andCD4+T cells and increased the number of specificCD8+/IFN-γ+T cells in lymphoid and nonlymphoid tissues in mice immunized by pB144. Immunization with pB144 andβ-glu6 increased the anti-HBc IgG and IgG2a antibody titer. These results demonstrate thatβ-glu6 can enhance the virus-specific CTL and Th1 responses induced by DNA vaccine, suggestingβ-glu6 as a candidate adjuvant in DNA vaccination.

scholarly journals Analysis of TCR Repertoire by High-Throughput Sequencing Indicates the Feature of T Cell Immune Response after SARS-CoV-2 Infection

Cells ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
Yifan Wang ◽  
Fugang Duan ◽  
Zhu Zhu ◽  
Meng Yu ◽  
Xiaodong Jia ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
High Throughput Sequencing ◽  
Cell Receptor ◽  
T Cell Response ◽  
Patient Specific ◽  
Cell Immune Response ◽  
Tcr Repertoire

Coronavirus disease 2019 (COVID-19) is a global infectious disease caused by the SARS-CoV-2 coronavirus. T cells play an essential role in the body’s fighting against the virus invasion, and the T cell receptor (TCR) is crucial in T cell-mediated virus recognition and clearance. However, little has been known about the features of T cell response in convalescent COVID-19 patients. In this study, using 5′RACE technology and PacBio sequencing, we analyzed the TCR repertoire of COVID-19 patients after recovery for 2 weeks and 6 months compared with the healthy donors. The TCR clustering and CDR3 annotation were exploited to discover groups of patient-specific TCR clonotypes with potential SARS-CoV-2 antigen specificities. We first identified CD4+ and CD8+ T cell clones with certain clonal expansion after infection, and then observed the preferential recombination usage of V(D) J gene segments in CD4+ and CD8+ T cells of COVID-19 patients with different convalescent stages. More important, the TRBV6-5-TRBD2-TRBJ2-7 combination with high frequency was shared between CD4+ T and CD8+ T cells of different COVID-19 patients. Finally, we found the dominant characteristic motifs of the CDR3 sequence between recovered COVID-19 and healthy control. Our study provides novel insights on TCR in COVID-19 with different convalescent phases, contributing to our understanding of the immune response induced by SARS-CoV-2.

scholarly journals Mapping and role of T cell response in SARS-CoV-2–infected mice

2021 ◽  
Vol 218 (4) ◽  
Author(s):  
Zhen Zhuang ◽  
Xiaomin Lai ◽  
Jing Sun ◽  
Zhao Chen ◽  
Zhaoyong Zhang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Response ◽  
T Cell Responses ◽  
T Cell Response ◽  
Target Cells ◽  
Type I ◽  
Cell Responses ◽  
T Cell Vaccination

Virus-specific T cells play essential roles in protection against multiple virus infections, including SARS-CoV and MERS-CoV. While SARS-CoV-2–specific T cells have been identified in COVID-19 patients, their role in the protection of SARS-CoV-2–infected mice is not established. Here, using mice sensitized for infection with SARS-CoV-2 by transduction with an adenovirus expressing the human receptor (Ad5-hACE2), we identified SARS-CoV-2–specific T cell epitopes recognized by CD4+ and CD8+ T cells in BALB/c and C57BL/6 mice. Virus-specific T cells were polyfunctional and were able to lyse target cells in vivo. Further, type I interferon pathway was proved to be critical for generating optimal antiviral T cell responses after SARS-CoV-2 infection. T cell vaccination alone partially protected SARS-CoV-2–infected mice from severe disease. In addition, the results demonstrated cross-reactive T cell responses between SARS-CoV and SARS-CoV-2, but not MERS-CoV, in mice. Understanding the role of the T cell response will guide immunopathogenesis studies of COVID-19 and vaccine design and validation.

scholarly journals Interleukin-2 enhances CD4+ T cell memory by promoting the generation of IL-7Rα–expressing cells

2007 ◽  
Vol 204 (3) ◽  
pp. 547-557 ◽  
Author(s):  
Hans Dooms ◽  
Kristen Wolslegel ◽  
Patricia Lin ◽  
Abul K. Abbas
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Interleukin 2 ◽  
T Cell Response ◽  
T Cell Homeostasis ◽  
Activation Markers ◽  
Term Survival ◽  
Cell Homeostasis ◽  
Memory T Cell

The common γ chain cytokines interleukin (IL)-2 and IL-7 are important regulators of T cell homeostasis. Although IL-2 is implicated in the acute phase of the T cell response, IL-7 is important for memory T cell survival. We asked whether regulated responsiveness to these growth factors is determined by temporal expression of the cytokine-specific IL-2 receptor (R) α and IL-7Rα chains. We demonstrate that IL-2Rα is expressed early after priming in T cell receptor–transgenic CD4+ T cells, whereas IL-7Rα expression is lost. In the later stage of the response, IL-7Rα is reexpressed while IL-2Rα expression is silenced. This reciprocal pattern of IL-2Rα/IL-7Rα expression is disturbed when CD4+ T cells are primed in the absence of IL-2 signals. Primed IL-2−/− or CD25−/− (IL-2Rα−/−) CD4+ T cells, despite showing normal induction of activation markers and cell division, fail to reexpress IL-7Rα late in the response. Because the generation of CD4+ memory T cells is dependent on IL-7–IL-7Rα interactions, primed IL-2−/− or CD25−/− CD4+ T cells develop poorly into long-lived memory cells. Retrovirus-mediated expression of IL-7Rα in IL-2−/− T cells restores their capacity for long-term survival. These results identify IL-2 as a factor regulating IL-7Rα expression and, consequently, memory T cell homeostasis in vivo.

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