scholarly journals Identification of Circulating Tfh/Th Subsets as Biomarker of Hospital-acquired Pneumonia

2021 ◽  
Author(s):  
Yuan Peng ◽  
Tao Tao ◽  
Ni-Wen Yu ◽  
Cheng Chen
Keyword(s):  
Immune Responses ◽  
Respiratory Function ◽  
Lower Respiratory Tract ◽  
Prognostic Biomarker ◽  
Healthy Individuals ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Tract Secretion ◽  
Hospital Acquired Pneumonia ◽  
Hospital Acquired

Abstract BackgroundThe incidence rate of hospital-acquired pneumonia (HAP) is increasing in ICU patients, which is usually associated with dysregulated immune responses. Previous study has revealed Follicular helper T (Tfh) cells were essential for the formation and maintenance of geminal centers for anti-viral immune response, however, little is known about it during HAP.MethodsA total number of 62 patients with HAP and 10 healthy individuals were recruited. Lower respiratory tract secretion and blood samples were taken for microbiological examinations. Uncontrolled and controlled HAP patients were identified on the basis of its respiratory function or hemodynamics, according to the ATS guidelines of HAP. Circulating Tfh cells (CXCR5+Foxp3-CD4+) and Th cells (CXCR5-FoxP3-CD4+) in all individuals were analyzed by flow cytometry.ResultsClinically, 34 patients had uncontrolled HAP and 28 patients were controlled HAP. Patients were mainly infected with Klebsiella pneumoniae (K.p), Acinetobacter baumannii, Escherichia coli, and Pseudomonas aeruginosa. It is noted that Tfh/Th ratio was increased in patients with uncontrolled HAP than controlled HAP (P<0.05). Especially, Tfh/Th ratio was also higher in K.p-infected than non-K.p-infected patients (P<0.05). Furthermore, Tfh/Th ratio was significantly elevated in patients with BSIs compared to those without BSIs (P<0.01). Furthermore, Tfh/Th ratio showed an association with PCT, and the combination of Tfh/Th and PCT could serve as a better predicting marker for deterioration of HAP. Accordingly, HAP patients with high Tfh/Th ratio had a lower rate of survival in 28 days.ConclusionTfh/Th ratio is useful for identifying the severity of the patients with HAP and increased Tfh/Th ratio indicates uncontrolled HAP. Circulating Tfh/Th subsets could be used as a prognostic biomarker and may provide novel insight for the pathogenesis of HAP.

scholarly journals Regulation of Intrinsic and Bystander T Follicular Helper Cell Differentiation and Autoimmunity by Tsc1

2021 ◽  
Vol 12 ◽  
Author(s):  
Shimeng Zhang ◽  
Lei Li ◽  
Danli Xie ◽  
Srija Reddy ◽  
John W. Sleasman ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
Immune Responses ◽  
B Cell ◽  
Regulatory Cells ◽  
Wild Type ◽  
Autoantibody Production ◽  
Cell Responses ◽  
Tfh Cells ◽  
Follicular Helper

T Follicular helper (Tfh) cells promote germinal center (GC) B cell responses to develop effective humoral immunity against pathogens. However, dysregulated Tfh cells can also trigger autoantibody production and the development of autoimmune diseases. We report here that Tsc1, a regulator for mTOR signaling, plays differential roles in Tfh cell/GC B cell responses in the steady state and in immune responses to antigen immunization. In the steady state, Tsc1 in T cells intrinsically suppresses spontaneous GC-Tfh cell differentiation and subsequent GC-B cell formation and autoantibody production. In immune responses to antigen immunization, Tsc1 in T cells is required for efficient GC-Tfh cell expansion, GC-B cell induction, and antigen-specific antibody responses, at least in part via promoting GC-Tfh cell mitochondrial integrity and survival. Interestingly, in mixed bone marrow chimeric mice reconstituted with both wild-type and T cell-specific Tsc1-deficient bone marrow cells, Tsc1 deficiency leads to enhanced GC-Tfh cell differentiation of wild-type CD4 T cells and increased accumulation of wild-type T regulatory cells and T follicular regulatory cells. Such bystander GC-Tfh cell differentiation suggests a potential mechanism that could trigger self-reactive GC-Tfh cell/GC responses and autoimmunity via neighboring GC-Tfh cells.

scholarly journals T follicular helper (Tfh) cells in normal immune responses and in allergic disorders

Allergy ◽  
2016 ◽  
Vol 71 (8) ◽  
pp. 1086-1094 ◽  
Author(s):  
G. Varricchi ◽  
J. Harker ◽  
F. Borriello ◽  
G. Marone ◽  
S. R. Durham ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Allergic Disorders

T Follicular Helper (TFH) Cells in Normal and Dysregulated Immune Responses

2008 ◽  
Vol 26 (1) ◽  
pp. 741-766 ◽  
Author(s):  
Cecile King ◽  
Stuart G. Tangye ◽  
Charles R. Mackay
Keyword(s):  
Immune Responses ◽  
Tfh Cells ◽  
Follicular Helper

scholarly journals Pre-vaccination Frequency of Circulatory Tfh is associated with Robust Immune Response to TV003 Dengue Vaccine

2021 ◽  
Author(s):  
Abdullah M Izmirly ◽  
Adam-Nicolas Pelletier ◽  
Jennifer Connors ◽  
Bhavani Taramangalam ◽  
Sawsan O. Alturki ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Dengue Virus ◽  
Vaccine Design ◽  
Neutralizing Antibody ◽  
Dengue Vaccine ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Tetravalent Vaccine ◽  
Immunological Mechanisms

AbstractIt has been estimated that more than 390 million people are infected with Dengue virus every year; around 96 millions of these infections result in clinical pathologies. To date, there is only one licensed viral vector-based Dengue virus vaccine CYD-TDV approved for use in dengue endemic areas. While initially approved for administration independent of serostatus, the current guidance only recommends the use of this vaccine for seropositive individuals. Therefore, there is a critical need for investigating the influence of Dengue virus serostatus and immunological mechanisms that influence vaccine outcome. Here, we provide comprehensive evaluation of sero-status and host immune factors that correlate with robust immune responses to a Dengue virus vector based tetravalent vaccine (TV003) in a Phase II clinical cohort of human participants. We observed that sero-positive individuals demonstrate a much stronger immune response to the TV003 vaccine. Our multi-layered immune profiling revealed that sero-positive subjects have increased baseline/pre-vaccination frequencies of circulating T follicular helper (cTfh) cells and the Tfh related chemokine CXCL13/BLC. Importantly, this baseline/pre-vaccination cTfh profile correlated with the vaccinees’ ability to launch neutralizing antibody response against all four sero-types of Dengue virus, an important endpoint for Dengue vaccine clinical trials. Overall, we provide novel insights into the favorable cTfh related immune status that persists in Dengue virus sero-positive individuals that correlate with their ability to mount robust vaccine specific immune responses. Such detailed interrogation of cTfh cell biology in the context of clinical vaccinology will help uncover mechanisms and targets for favorable immuno-modulatory agents.Author summaryDengue virus (DENV) is a worldwide threat that causes significant health and economic burden. Currently, there are several challenges in the development of a DENV vaccine including the existence of four different serotypes all; capable of causing disease and antibody dependent enhancement (ADE). For complete protection, a vaccine must be able to generate neutralizing antibodies against all 4 serotypes to avoid ADE. Currently, there is one licensed DENV vaccine, CYD-TDV (DENGVAXIATM). However, this vaccine is only efficacious in protecting against severe disease in DENV seropositive individuals therefore serostatus effect must be further studied for optimal vaccine design. A subset of CD4+ T cells called T-follicular helper (Tfh) cells have been well known to play a major role in aiding high affinity antibody production. Therefore, we chose to look at subsets of Tfh and the cytokines they produce in human blood that can serve as biomarkers for effective vaccine design. We found that DENV sero-positive participants had increased pre-vaccination frequencies of Tfh cells and higher levels of the Tfh related chemokine CXCL13/BLC that plays a role in directing antigen-specific responses. This pre-vaccination Tfh profile and CXCL13/BLC are then correlated positively with the vaccinees’ ability to produce neutralizing antibody against all four sero-types (breadth of the Response) of DENV, an important goal for all DENV vaccine trials.

scholarly journals Langerhans cells and cDC1s play redundant roles in mRNA-LNP induced protective anti-influenza and anti-SARS-CoV-2 responses

2021 ◽  
Author(s):  
Sonia Ndeupen ◽  
Aurelie Bouteau ◽  
Christopher Herbst ◽  
Zhen Qin ◽  
Zachary Hutchins ◽  
...  
Keyword(s):  
Immune Responses ◽  
Langerhans Cells ◽  
Lethal Challenge ◽  
Humoral Immune ◽  
Adaptive Immune ◽  
Tfh Cells ◽  
Humoral Immune Responses ◽  
Follicular Helper ◽  
Independent Mechanism ◽  
Antibody Titers

Nucleoside modified mRNA combined with Acuitas Therapeutics' lipid nanoparticles (LNP) have been shown to support robust humoral immune responses in many preclinical animal vaccine studies and later in humans with the SARS-CoV-2 vaccination. We recently showed that this platform is highly inflammatory due to the LNPs' ionizable lipid component. The inflammatory property is key to support the development of potent humoral immune responses. However, the mechanism by which this platform drives T follicular helper cells (Tfh) and humoral immune responses remains unknown. Here we show that lack of Langerhans cells or cDC1s neither significantly affected the induction of PR8 HA and SARS-CoV-2 RBD-specific Tfh cells and humoral immune responses, nor susceptibility towards the lethal challenge of influenza and SARS-CoV-2. However, the combined deletion of these two DC subsets led to a significant decrease in the induction of PR8 HA and SARS-CoV-2 RBD-specific Tfh cell and humoral immune responses. Despite these observed defects, the still high antibody titers were sufficient to confer protection towards lethal viral challenges. We further found that IL-6, but not neutrophils, was required to generate Tfh cells and antibody responses. In summary, here we bring evidence that the mRNA-LNP platform can support protective adaptive immune responses in the absence of specific DC subsets through an IL-6 dependent and neutrophil independent mechanism.

scholarly journals THU0231 IL-2 DRIVES THE CONVERSION OF T FOLLICULAR HELPER TO T FOLLICULAR REGULATORY CELLS THROUGH EPIGENETIC MODIFICATION IN SYSTEMIC LUPUS ERYTHEMATOSUS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 343.2-343
Author(s):  
H. Hao ◽  
S. Nakayamada ◽  
Y. Kaoru ◽  
N. Ohkubo ◽  
S. Iwata ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Flow Cytometry ◽  
B Cells ◽  
Histone Modifications ◽  
Lupus Erythematosus ◽  
Regulatory Cells ◽  
Systemic Lupus ◽  
Research Support ◽  
Tfh Cells ◽  
Follicular Helper

Background:Systemic lupus erythematosus (SLE) is a complex polygenic autoimmune disease characterized by immune-system aberrations. Among several types of immune cells, T follicular helper (Tfh) cells promote autoantibody production, whereas T follicular regulatory (Tfr) cells suppress Tfh-mediated antibody responses.(1)Objectives:To identify the characteristics of Tfr cells and to elucidate the mechanisms of conversion of Tfh cells to Tfr cells, we probed the phenotype of T helper cells in patients with SLE and underlying epigenetic modifications by cytokine-induced signal transducer and activators of transcription (STAT) family factors.Methods:Peripheral blood mononuclear cells from SLE patients (n=44) and healthy donors (HD; n=26) were analyzed by flow cytometry. Memory Tfh cells were sorted and cultured under stimulation with T cell receptor and various cytokines. Expression of characteristic markers and phosphorylation of STATs (p-STATs) were analyzed by flow cytometry and quantitation PCR. Histone modifications were evaluated by chromatin immunoprecipitation.Results:The proportion of CXCR5+FoxP3+Tfr cells in CD4+T cells tended to increase (2.1% vs 1.7%, p=0.17); however, that of CD4+CD45RA-FoxP3hiactivated Tfr cells in Tfr cells was decreased (4.8% vs 7.1%, p<0.05), while CD4+CD45RA-FoxP3lownon-suppressive Tfr cells was increased (50.1% vs 38.2%, p<0.01) in SLE compared to HD. The percentage of PD-1hiactivated Tfh cells was significantly higher in SLE compared to HD (15.7% vs 5.9%, p<0.01). Furthermore, active patients had a higher ratio of activated Tfh/Tfr cells compared to inactive patients. In vitro study showed that IL-2, but not other cytokines such as TGF-β1, IL-12, IL-27, and IL-35, induced the conversion of memory Tfh cells to functional Tfr cells characterized by CXCR5+Bcl6+Foxp3hipSTAT3+pSTAT5+cells. The loci ofFOXP3at STAT binding sites were marked by bivalent histone modifications. After IL-2 stimulation, STAT5 directly bound on FOXP3 gene loci accompanied by suppressing H3K27me3. Finally, we found that serum level of IL-2 was decreased in SLE and that stimulation with IL-2 suppressed the generation of CD38+CD27+B cells by ex vivo coculture assay using Tfh cells and B cells isolated from human blood.Conclusion:Our findings indicated that the regulatory function of Tfr cells is impaired due to the low ability of IL-2 production and that IL-2 restores the function of Tfr cells through conversion of Tfh cells to Tfr cells in SLE. Thus, the reinstatement of the balance between Tfh and Tfr cells will provide important therapeutic approaches for SLE.References:[1]Deng J, Wei Y, Fonseca VR, et al. T follicular helper cells and T follicular regulatory cells in rheumatic diseases. Nat Rev Rheumatol. 2019; 15 (8): 475-90.Disclosure of Interests: :He Hao: None declared, Shingo Nakayamada Grant/research support from: Mitsubishi-Tanabe, Takeda, Novartis and MSD, Speakers bureau: Bristol-Myers, Sanofi, Abbvie, Eisai, Eli Lilly, Chugai, Asahi-kasei and Pfizer, Yamagata Kaoru: None declared, Naoaki Ohkubo: None declared, Shigeru Iwata: None declared, Yoshiya Tanaka Grant/research support from: Asahi-kasei, Astellas, Mitsubishi-Tanabe, Chugai, Takeda, Sanofi, Bristol-Myers, UCB, Daiichi-Sankyo, Eisai, Pfizer, and Ono, Consultant of: Abbvie, Astellas, Bristol-Myers Squibb, Eli Lilly, Pfizer, Speakers bureau: Daiichi-Sankyo, Astellas, Chugai, Eli Lilly, Pfizer, AbbVie, YL Biologics, Bristol-Myers, Takeda, Mitsubishi-Tanabe, Novartis, Eisai, Janssen, Sanofi, UCB, and Teijin

scholarly journals Arginase 1 (Arg1) as an Up-Regulated Gene in COVID-19 Patients: A Promising Marker in COVID-19 Immunopathy

2021 ◽  
Vol 10 (5) ◽  
pp. 1051 ◽  
Author(s):  
Afshin Derakhshani ◽  
Nima Hemmat ◽  
Zahra Asadzadeh ◽  
Moslem Ghaseminia ◽  
Mahdi Abdoli Shadbad ◽  
...  
Keyword(s):  
Immune Responses ◽  
Whole Blood ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Rna Extraction ◽  
Diagnostic Value ◽  
Healthy Individuals ◽  
Cdna Synthesis ◽  
Arginase 1 ◽  
Global Pandemic

Background: The coronavirus disease 2019 (COVID-19) outbreak, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a global pandemic. It is well-established that SARS-CoV-2 infection can lead to dysregulated immune responses. Arginase-1 (Arg1), which has a pivotal role in immune cells, can be expressed in most of the myeloid cells, e.g., neutrophils and macrophages. Arg1 has been associated with the suppression of antiviral immune responses. Methods: Whole blood was taken from 21 COVID-19 patients and 21 healthy individuals, and after RNA extraction and complementary DNA (cDNA) synthesis, gene expression of Arg1 was measured by real-time PCR. Results: The qPCR results showed that the expression of Arg1 was significantly increased in COVID-19 patients compared to healthy individuals (p < 0.01). The relative expression analysis demonstrated there were approximately 2.3 times increased Arg1 expression in the whole blood of COVID-19 patients. Furthermore, the receiver operating characteristic (ROC) analysis showed a considerable diagnostic value for Arg1 expression in COVID-19 (p = 0.0002 and AUC = 0.8401). Conclusion: Arg1 might be a promising marker in the pathogenesis of the disease, and it could be a valuable diagnostic tool.

scholarly journals Screening and development of monoclonal antibodies for identification of ferret T follicular helper cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenbo Jiang ◽  
Julius Wong ◽  
Hyon-Xhi Tan ◽  
Hannah G. Kelly ◽  
Paul G. Whitney ◽  
...  
Keyword(s):  
Animal Model ◽  
Monoclonal Antibodies ◽  
Lymph Node ◽  
Cross Reactivity ◽  
Tfh Cells ◽  
Follicular Helper ◽  
Lymph Node Cells ◽  
Human Viruses ◽  
Humoral Responses ◽  
Murine Monoclonal Antibodies

AbstractThe ferret is a key animal model for investigating the pathogenicity and transmissibility of important human viruses, and for the pre‐clinical assessment of vaccines. However, relatively little is known about the ferret immune system, due in part to a paucity of ferret‐reactive reagents. In particular, T follicular helper (Tfh) cells are critical in the generation of effective humoral responses in humans, mice and other animal models but to date it has not been possible to identify Tfh in ferrets. Here, we describe the screening and development of ferret-reactive BCL6, CXCR5 and PD-1 monoclonal antibodies. We found two commercial anti-BCL6 antibodies (clone K112-91 and clone IG191E/A8) had cross-reactivity with lymph node cells from influenza-infected ferrets. We next developed two murine monoclonal antibodies against ferret CXCR5 (clone feX5-C05) and PD-1 (clone fePD-CL1) using a single B cell PCR-based method. We were able to clearly identify Tfh cells in lymph nodes from influenza infected ferrets using these antibodies. The development of ferret Tfh marker antibodies and the identification of ferret Tfh cells will assist the evaluation of vaccine-induced Tfh responses in the ferret model and the design of novel vaccines against the infection of influenza and other viruses, including SARS-CoV2.

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