ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 1783

TNFα Influences RasGRP1 and RasGRP3 Expression Levels in PBMC, B and T Cells

Marie-Laure Potier1, Martine Hiron1, Clément Guillou1, Céline Derambure2, Olivier Boyer3, Xavier Le Loët4, Olivier Vittecoq5 and Thierry Lequerré6, 1Inserm 905 & Institute for Biomedical Research, University of Rouen, Rouen, France, 2Inserm 905 & Institute for Biomedical Research, University of Rouen, Rouen, France, Rouen, France, 3Immunology, Inserm 905, Institute for Biomedical research, University of Rouen, Rouen, France, 4Rheumatology Department, Department of Rheumatology, Rouen University Hospital & Inserm 905, Institute for Biomedical Research, University of Rouen, Rouen Cedex, France, 5Rheumatology, Department of Rheumatology, Rouen University Hospital & Inserm 905, Institute for Biomedical Research, University of Rouen, Rouen Cedex, France, 6Rheumatology Department & Inserm 905, Department of Rheumatology, Rouen University Hospital & Inserm 905, Institute for Biomedical Research, University of Rouen, Rouen Cedex, France

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: B cells, monocytes, rheumatoid arthritis (RA) and tumor necrosis factor (TNF), T cells

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print
Session Information

Title: Cytokines, Mediators, and Gene Regulation

Session Type: Abstract Submissions (ACR)

Background/Purpose: Rheumatoid arthritis (RA) is the most common inflammatory arthritis. B and T lymphocytes play a central role in the pathophysiology of RA. RasGRP is a member of the CDC25 family of Ras guanyl nucleotide exchange factors. RasGRP1 is expressed in T and B cells whereas RasGRP3 is only expressed in B cells. In previous studies, we have shown that RasGRP3expression level significantly decreased in Peripheral blood mononuclear cells (PBMC) from RA patients responders to adalimumab after 3 months, leading to the question of TNFα involvement in pathways including RasGRP1 and RasGRP3. Objectives : To study TNFα effect on RasGRP1 and RasGRP3 expression levels in vitro.

Methods: We measured by qRT-PCR, RasGRP1 and RasGRP3 expression levels, i) in PBMC from 3 healthy controls (HC), ii) in negative selected B and T cells from PBMC isolated from 3 buffy coat. In each condition, cells were cultured with or without BCR or TCR stimulation for 4 days and TNFα was added for 24 or 48 hours. Immunofluorescence staining was performed to check the cell purity and B and T cells stimulation by flow cytometry. Moreover, IL-2 production was measured by ELISA in T-cells before and after TNFα stimulation. In addition, TNFα effects on cell proliferation were evaluated by [3H] thymidine incorporation by the B and T cells.

Results: In B cells, TNFα induced an increase of RasGRP1 (p<0.001) and RasGRP3 (p<0.001) expression levels in absence of BCR stimulation. In the same way, in T cells, TNFα induced an increase of RasGRP1 (p<0.001) and RasGRP3 (p<0.001) expression levels in absence of TCR stimulation. Furthermore, TNFα induced a significantly increased of IL-2 production (p<0.05) in unstimulated T-cells. However, TNFα have no effects on B and T cells proliferation

Conclusion: This study suggests the RasGRP1 and RasGRP3 regulation by TNFα, independently of B and T cells stimulation. The increasing of RasGRP3 and RasGRP1 in B and T cells specifically via TNFα binding on its receptors could promote the activation and proliferation of B and T cells using another signaling pathway than BCR and TCR. This second pathway could explain the maintenance of B and T cells activation by an independent antigen pathway.


Disclosure:

M. L. Potier,
None;

M. Hiron,
None;

C. Guillou,
None;

C. Derambure,
None;

O. Boyer,
None;

X. Le Loët,
None;

O. Vittecoq,
None;

T. Lequerré,
None.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/tnf%ce%b1-influences-rasgrp1-and-rasgrp3-expression-levels-in-pbmc-b-and-t-cells/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology