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BRIEF RESEARCH REPORT article

Front. Immunol.
Sec. Autoimmune and Autoinflammatory Disorders : Autoimmune Disorders
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1491616

A minority of proliferating human CD4 + T cells in antigen-driven proliferation assays are antigen specific

Provisionally accepted
Pushpak Bhattacharjee Pushpak Bhattacharjee 1Miha Pakusch Miha Pakusch 1Matthew Lacorcia Matthew Lacorcia 1Chris Chiu Chris Chiu 1Xin Liu Xin Liu 2Eleonora Tresoldi Eleonora Tresoldi 1Abby Foster Abby Foster 1Laura King Laura King 1Fergus Cameron Fergus Cameron 3Stuart I. Mannering Stuart I. Mannering 1*
  • 1 St Vincents Institute of Medical Research, University of Melbourne, Fitzroy, Australia
  • 2 Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  • 3 Royal Children's Hospital, Melbourne, Victoria, Australia

The final, formatted version of the article will be published soon.

    Antigen-driven T-cell proliferation is often measured using fluorescent dye dilution assays, such as the CFSE-Based Proliferation Assay. Dye dilution assays have been powerful tools to detect human CD4+ T-cell responses, particularly against autoantigens. However, it is not known how many cells within the proliferating population are specific for the stimulating antigen. Here we determined the frequency of CD4+ T cells specific for the stimulating antigen within the antigen responsive population of CFSE-based proliferation assays. We compared CD4+ T cell responses to a type 1 diabetes autoantigen, (proinsulin C-peptide) and to a vaccine antigen (tetanus toxoid). The TCRs expressed by antigen-responsive CD4+ T cells were sequenced and their antigen specificity was tested functionally by expressing them in a reporter T-cell line. Responses to C-peptide were weak, but detectable, in PBMC from individuals with T1D; whereas responses to tetanus toxoid were much stronger. The frequency of antigen specific CD4+ T cells correlated with the strength of the response to antigen in the proliferation assay. However, antigen specific CD4+ T cells were rare amongst antigen-responsive CD4+ T cells. For C-peptide, an average frequency of 7.5% (1-11%, n=4) of antigen-responsive CD4+ T cells were confirmed to be antigen specific. In the tetanus toxoid stimulated cultures on average of 45% (16-78 %, n=5) of the antigen-responsive CD4+ T cells were tetanus toxoid specific. These data show that antigen specific CD4+ T cells are a minority of the cells that proliferate in response to antigen and have important implications for in vitro CD4+ T-cell proliferation assays.

    Keywords: Clonal expansion, proliferation, Cd4 + t cell, Autoimmunity, antigen specific T cell, C-Peptide, Tetanus Toxoid, CFSE assay

    Received: 05 Sep 2024; Accepted: 01 Oct 2024.

    Copyright: © 2024 Bhattacharjee, Pakusch, Lacorcia, Chiu, Liu, Tresoldi, Foster, King, Cameron and Mannering. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Stuart I. Mannering, St Vincents Institute of Medical Research, University of Melbourne, Fitzroy, Australia

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