scholarly journals A highly efficient T-cell immunoassay provides assessment of B cell help function of SARS-CoV-2 specific memory CD4+ T cells

2021 ◽  
Author(s):  
Asgar Ansari ◽  
Shilpa Sachan ◽  
Bimal Prasad Jit ◽  
Ashok Sharma ◽  
Poonam Coshic ◽  
...  
Keyword(s):  
T Cells ◽  
B Cell ◽  
Cd4 T Cells ◽  
Cultured Cells ◽  
Natural Infection ◽  
Qualitative Assessment ◽  
Lectin Domain ◽  
Highly Efficient ◽  
Specific Memory ◽  
Memory Cd4 T Cells

The B cell help function of CD4+ T cells may serve as an immunologic correlate of protective adaptive immunity. The quantitative assessment of the B cell help potential of CD4+ T cells is limited by the lack of suitable antigen-specific functional assays. Here, we describe a highly efficient antigen-specific T-B co-cultures for quantitative measurement of T-dependent B cell responses. Using Mycobacterium tuberculosis specific setup, we show that early priming and activation of CD4+ T cells is important for the mutualistic collaboration between antigen-specific T and B cells, which could be achieved by supplementing the co-cultures with autologous monocytes. We further show that monocyte-derived growth factors provide the impetus for productive T-B collaboration by conferring optimal survivability in the cultured cells. This study provides first evidence of C‐type lectin domain family 11 member A (CLEC11A/SCGF) as an essential growth factor for B cell survival. Importantly, we demonstrate the successful translation of monocyte supplemented T-B co-cultures in qualitative assessment of SARS-CoV-2 specific memory CD4+ T cells by quantifying several correlates of productive T-B cross-talk like plasma cell output, secreted antibody, antibody secreting cells and IL21 secreting T cells. Thus, the method described here can provides qualitative assessment of SARS-CoV-2 spike CD4+ T cells after natural infection and can be applied to assess the B cell help function of memory CD4+ T cells generated in response to COVID-19 vaccine.

scholarly journals Memory CD4 T Cells Direct Protective Responses to Influenza Virus in the Lungs through Helper-Independent Mechanisms

2010 ◽  
Vol 84 (18) ◽  
pp. 9217-9226 ◽  
Author(s):  
John R. Teijaro ◽  
David Verhoeven ◽  
Carly A. Page ◽  
Damian Turner ◽  
Donna L. Farber
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
T Cell ◽  
Cd4 T Cells ◽  
Natural Infection ◽  
Influenza Virus Infection ◽  
Cd4 T Cell ◽  
Virus Challenge ◽  
Specific Memory ◽  
Memory Cd4 T Cells

ABSTRACT Memory CD4 T cells specific for influenza virus are generated from natural infection and vaccination, persist long-term, and recognize determinants in seasonal and pandemic influenza virus strains. However, the protective potential of these long-lived influenza virus-specific memory CD4 T cells is not clear, including whether CD4 T-cell helper or effector functions are important in secondary antiviral responses. Here we demonstrate that memory CD4 T cells specific for H1N1 influenza virus directed protective responses to influenza virus challenge through intrinsic effector mechanisms, resulting in enhanced viral clearance, recovery from sublethal infection, and full protection from lethal challenge. Mice with influenza virus hemagglutinin (HA)-specific memory CD4 T cells or polyclonal influenza virus-specific memory CD4 T cells exhibited protection from influenza virus challenge that occurred in the presence of CD8-depleting antibodies in B-cell-deficient mice and when CD4 T cells were transferred into lymphocyte-deficient RAG2−/− mice. Moreover, the presence of memory CD4 T cells mobilized enhanced T-cell recruitment and immune responses in the lung. Neutralization of gamma interferon (IFN-γ) production in vivo abrogated memory CD4 T-cell-mediated protection from influenza virus challenge by HA-specific memory T cells and heterosubtypic protection by polyclonal memory CD4 T cells. Our results indicate that memory CD4 T cells can direct enhanced protection from influenza virus infection through mobilization of immune effectors in the lung, independent of their helper functions. These findings have important implications for the generation of universal influenza vaccines by promoting long-lived protective CD4 T-cell responses.

scholarly journals Th1-like Plasmodium -Specific Memory CD4 + T Cells Support Humoral Immunity

Cell Reports ◽  
2017 ◽  
Vol 21 (7) ◽  
pp. 1839-1852 ◽  
Author(s):  
Ryan A. Zander ◽  
Rahul Vijay ◽  
Angela D. Pack ◽  
Jenna J. Guthmiller ◽  
Amy C. Graham ◽  
...  
Keyword(s):  
T Cells ◽  
Humoral Immunity ◽  
Cd4 T Cells ◽  
Specific Memory ◽  
Memory Cd4 T Cells

scholarly journals Ex Vivo Phenotype and Frequency of Influenza Virus-Specific CD4 Memory T Cells

2004 ◽  
Vol 78 (13) ◽  
pp. 7284-7287 ◽  
Author(s):  
Michaela Lucas ◽  
Cheryl L. Day ◽  
Jessica R. Wyer ◽  
Sharon L. Cunliffe ◽  
Andrew Loughry ◽  
...  
Keyword(s):  
T Cells ◽  
Influenza Virus ◽  
Cd4 T Cells ◽  
Memory T Cells ◽  
Ex Vivo ◽  
Class Ii ◽  
Low Frequencies ◽  
Tetramer Staining ◽  
Specific Memory ◽  
Memory Cd4 T Cells

ABSTRACT Recent advances in class II tetramer staining technology have allowed reliable direct ex vivo visualization of antigen-specific CD4 T cells. In order to define the frequency and phenotype of a prototype response to a nonpersistent pathogen, we have used such techniques to analyze influenza virus-specific memory CD4 T cells directly from blood. These responses are stably detectable ex vivo at low frequencies (range, 0.00012 to 0.0061% of CD4 T cells) and display a distinct “central memory” CD62L+ phenotype.

scholarly journals HIV-1 Viremia Prevents the Establishment of Interleukin 2–producing HIV-specific Memory CD4+ T Cells Endowed with Proliferative Capacity

2003 ◽  
Vol 198 (12) ◽  
pp. 1909-1922 ◽  
Author(s):  
Souheil-Antoine Younes ◽  
Bader Yassine-Diab ◽  
Alain R. Dumont ◽  
Mohamed-Rachid Boulassel ◽  
Zvi Grossman ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd4 T Cells ◽  
Cd4 T Cell ◽  
Memory Cells ◽  
Cell Responses ◽  
Specific Memory ◽  
Ifn Γ ◽  
Memory Cd4 T Cells

CD4+ T cell responses are associated with disease control in chronic viral infections. We analyzed human immunodeficiency virus (HIV)-specific responses in ten aviremic and eight viremic patients treated during primary HIV-1 infection and for up to 6 yr thereafter. Using a highly sensitive 5-(and-6)-carboxyfluorescein diacetate-succinimidyl ester–based proliferation assay, we observed that proliferative Gag and Nef peptide-specific CD4+ T cell responses were 30-fold higher in the aviremic patients. Two subsets of HIV-specific memory CD4+ T cells were identified in aviremic patients, CD45RA− CCR7+ central memory cells (Tcm) producing exclusively interleukin (IL)-2, and CD45RA− CCR7− effector memory cells (Tem) that produced both IL-2 and interferon (IFN)-γ. In contrast, in viremic, therapy-failing patients, we found significant frequencies of Tem that unexpectedly produced exclusively IFN-γ. Longitudinal analysis of HIV epitope–specific CD4+ T cells revealed that only cells that had the capacity to produce IL-2 persisted as long-term memory cells. In viremic patients the presence of IFN-γ–producing cells was restricted to periods of elevated viremia. These findings suggest that long-term CD4+ T cell memory depends on IL-2–producing CD4+ T cells and that IFN-γ only–producing cells are short lived. Our data favor a model whereby competent HIV-specific Tcm continuously arise in small numbers but under persistent antigenemia are rapidly induced to differentiate into IFN-γ only–producing cells that lack self-renewal capacity.

scholarly journals Detection of Epstein-Barr virus-specific memory CD4+T cells using a peptide-based cultured enzyme-linked immunospot assay

Immunology ◽  
2013 ◽  
Vol 139 (4) ◽  
pp. 533-544 ◽  
Author(s):  
Sandra A. Calarota ◽  
Antonella Chiesa ◽  
Paola Zelini ◽  
Giuditta Comolli ◽  
Lorenzo Minoli ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Epstein Barr Virus ◽  
Barr Virus ◽  
Specific Memory ◽  
Epstein Barr ◽  
Memory Cd4 T Cells

The kinase complex mTORC2 promotes the longevity of virus-specific memory CD4+ T cells by preventing ferroptosis

2021 ◽  
Author(s):  
Yifei Wang ◽  
Qin Tian ◽  
Yaxing Hao ◽  
Wei Yao ◽  
Jinjin Lu ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Specific Memory ◽  
Memory Cd4 T Cells

Single-Cell Analysis of FVIII-Specific Memory B Cells in Murine Hemophilia A.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1157-1157 ◽  
Author(s):  
Christina Hausl ◽  
Rafi U. Ahmad ◽  
Bernhard Baumgartner ◽  
Hans Peter Schwarz ◽  
Hartmut Ehrlich ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Single Cell ◽  
Cd4 T Cells ◽  
Single Cell Analysis ◽  
Memory B Cells ◽  
Cell Analysis ◽  
Memory B Cell ◽  
Specific Memory

Abstract The elimination of FVIII-specific memory B cells is an essential step in the design of new therapeutic strategies for the induction of immune tolerance in hemophilia A with FVIII inhibitors. Using a mouse model of hemophilia A we recently reported that low dose FVIII stimulates the differentiation of FVIII-specific memory B cells into antibody-secreting plasma cells whereas high dose FVIII inhibits this process. The inhibition of memory-B-cell re-stimulation is irreversible and seems to be due to an induction of apoptosis. Further understanding of the complex interactions that lead to either re-stimulation and differentiation of memory B cells or inhibition and eradication of these cells requires appropriate technologies for single-cell analysis and functional studies. We established a new technology for single-cell analysis and cell sorting of FVIII-specific murine memory B cells. A combination of magnetic bead separation and multi-color flow cytometry enabled us to analyze and purify FVIII-specific memory B cells obtained from hemophilic mice treated with FVIII. In a first step, we depleted undesirable cell populations (IgM+, IgD+, CD11c+, F4/80+, Gr1+ and CD49b+ cells) from total spleen cells by magnetic bead separation. In a second step, we used multicolor flow cytometry to exclude CD4+ T cells and analyze the FVIII-specific memory B cell compartment. This compartment was specified by staining the specific B-cell receptor with FVIII and anti-IgG antibodies. Frequencies of cells in this compartment ranged from 0.1–0.5% of total spleen cells in animals treated with 4 intravenous doses of FVIII, given at weekly intervals. We could not detect any FVIII-specific memory B cells in naïve mice. By means of single cell sorting we isolated FVIII-specific memory B cells for further functional studies. We were able to cultivate FVIII-specific memory B cells in microwell cultures in vitro and differentiate them into antibody-secreting plasma cells. The re-stimulation and differentiation of single-cell sorted memory B cells was strictly dependent on the presence of activated CD4+ T cells. CD4+ T cells obtained from naïve mice did not support the memory response. Furthermore, the re-stimulation and differentiation of memory B cells in the presence of activated CD4+ T cells did not require additional dendritic cells for antigen presentation. Obviously, memory B cells provide sufficient antigen presentation to CD4+ T cells to enable them to trigger the memory response. Our approach for single-cell analysis and purification of FVIII-specific memory B cells provides a new tool for tracking memory B cell populations in vivo and for directly analyzing the regulation of memory B cell function. It opens the field for future studies which should elucidate signals and molecules involved in activation or inhibition and eradication of FVIII-specific memory B cells. These activities will eventually lead to the identification of targets for the design of new treatment strategies for patients with FVIII inhibitors.

Sign in / Sign up

Export Citation Format

Share Document