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: 1847

Expression Levels of the ATP-Gated Ion Channel P2RX7 Do Not Predict T Cell Sensitivity to Extracellular ATP and NAD

William Valente1, Ka Hyun Rhee2, Kelsey Wanhainen2 and Stephen Jameson2, 1University of Minnesota, Burnsville, MN, 2University of Minnesota, Minneapolis, MN

Meeting: ACR Convergence 2024

Keywords: immunology, Mouse, signal transduction

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

Date: Monday, November 18, 2024

Title: T Cell Biology & Targets in Autoimmune & Inflammatory Disease Poster

Session Type: Poster Session C

Session Time: 10:30AM-12:30PM

Background/Purpose: Extracellular NAD+ and ATP are two of the many damage-associated molecular pattern molecules (DAMPs) released at sites of tissue damage which modify activities of the innate and adaptive immune systems. Among cell-surface proteins which detect these molecules in mice, the NAD+-responsive, ADP-ribosyltransferase ARTC2.2 and the ATP-dependent ion channel P2RX7 represent two members of a pathway which controls T cell homeostasis. P2RX7 is pivotal for development and maintenance of long-lived central and tissue-resident memory T cells (T­RM). However, covalent ADP-ribosylation of P2RX7 by ARTC2.2 in response to NAD+ enhances persistent non-selective pore formation by P2RX7, causing activation of matrix metalloproteases which cleave cell surface markers including CD27 and CD62L, cell membrane depolarization, and cell death. ARTC2.2/P2RX7 activity occurs at both physiologic levels of NAD+ and ATP during the extraction of immune cells from tissues for investigation, leading to cell death. Amongst cells with high expression of both ARTC2.2 and P2RX7, this sensitivity to so-called NAD-induced cell death (NICD) has led to methodologic difficulties extending characterization of immune responses from murine models to human physiology.  Furthermore, humans lack a functional equivalent of ARTC2.2.

Methods: We developed a novel, germline Art2b -/- mouse line via CRISPR. Circulating, lymph node-derived, splenic, or tissue-resident lymphocytes from Art2b -/- mice, P2rx7 -/- mice, and wild-type controls were extracted conventionally and/or in the presence of ARCT2.2 antagonistic nanobody or commercially-available P2RX7-specific small-molecule inhibitor A-740003. Lymphocytes were subjected ex vivo to incubation with NAD+ or ATP analogue, bzATP. Mixed tissue isolates were assessed by spectral flow cytometry for viability and presence of cell surface markers. 

Results: Art2b -/- mice resist ex vivo NICD compared to WT controls across all major conventional T-cell subsets tested. Consistent with known ARTC2.2 function, downstream activation of P2RX7 and proteolytic cleavage of CD27 and CD62L following NAD exposure is near-completely obviated in Art2b -/- T cells, whereas sensitivity to extracellular ATP is preserved. P2rx7 -/- mice or treatment with A-740003 attenuate, NICD, ATP-induced cell death, and CD27/CD62L shedding. Surprisingly, naïve CD8+ T cells demonstrate particular P2RX7-mediated sensitivity to extracellular ATP, despite minimal expression of P2RX7. Additionally, Art2b -/- mice have greater retrieval of viable T cell populations compared to WT or ARTC2.2 antagonistic nanobody.

Conclusion: Our results with naïve CD8+ T cells suggest a greater role for ARTC2.2/P2RX7 pathway activity in regulating T cell phenotype and homeostasis than is conventionally assumed. These investigations provide a promising inroad to further characterize the roles of NAD- and ATP-induced cell death on both naïve and mature T cell populations and the full diversity of tissue-resident T cells as they relate to models of acute and chronic diseases. As well, since ARTC2.2-mediated NICD is unique to rodents, further studies using Art2b-/- mice may provide a more accurate model for regulation human T cells.

Supporting image 1

Figure 1. P2RX7 is lowly expressed on naïve and CD8 populations compared to memory (CD44+) T cell subsets, by contrast ARTC2.2 is found in abundance on both CD4+ and CD8+ subsets. (A) Flow cytometry analysis of isolated splenocytes from uninfected WT and CD4-Cre P2rx7 Exon 2 floxed KO B6/N mice (grey outline) with expression comparisons by subtype between WT and P2RX7 KO. Data from 4 mice isolates across 2 experiments. (B) Flow cytometry of uninfected WT B6/J and homozygous germline CRISPR-generated Art2b Exon 2 KO mice.

Supporting image 2

Figure 2. BzATP, but not NAD+, induces ARTC2.2 / P2RX7 mediated CD27 and CD62L shedding in WT but not ARTC2.2 KO mice T cell subsets. Isolated lymphocytes from mice spleens were incubated ex vivo with NAD+ or BzATP for 30’ at 37C prior to antibody staining and spectral flow cytometry. Mice in the right-most column were pretreated prior to harvest with ARTC2.2 antagonistic nanobody (NB).

Supporting image 3

Figure 3. P2RX7 -/- mouse lymphocytes from spleen and lymph node are resistant to NAD+ and ATP-induced CD27 and CD62L shedding. Among WT T cell subsets, naïve CD8+ cells are more sensitive than their antigen-experienced (CD44+) counterparts. ARTC2.2 antagonistic nanobody (NB) does not significantly alter P2RX7 -/- cell responsiveness to NAD+ or ATP+.


Disclosures: W. Valente: None; K. Rhee: None; K. Wanhainen: None; S. Jameson: None.

To cite this abstract in AMA style:

Valente W, Rhee K, Wanhainen K, Jameson S. Expression Levels of the ATP-Gated Ion Channel P2RX7 Do Not Predict T Cell Sensitivity to Extracellular ATP and NAD [abstract]. Arthritis Rheumatol. 2024; 76 (suppl 9). https://acrabstracts.org/abstract/expression-levels-of-the-atp-gated-ion-channel-p2rx7-do-not-predict-t-cell-sensitivity-to-extracellular-atp-and-nad/. Accessed .
  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to ACR Convergence 2024

ACR Meeting Abstracts - https://acrabstracts.org/abstract/expression-levels-of-the-atp-gated-ion-channel-p2rx7-do-not-predict-t-cell-sensitivity-to-extracellular-atp-and-nad/

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