Pancreatic lipase-related protein 2 (PLRP2) induction by IL-4 in cytotoxic T lymphocytes (CTLs) and reevaluation of the negative effects of its gene ablation on cytotoxicity

Bryce N. Alves, Jeff Leong, David L. Tamang, Viki Elliott, Jillian Edelnant, Doug Redelman, Cherie A. Singer, Andrew R. Kuhn, Rita Miller, Mark E. Lowe, Dorothy Hudig

Research output: Contribution to journalArticle

3 Scopus citations

Abstract

Pancreatic lipase-related protein 2 (PLRP2) is induced by IL-4 in vitro in cytotoxic T lymphocyte (CTL) clones and CTLs from immunized wild-type (WT) PLRP2+/+ are more cytotoxic than PLRP2-/- CTLs, suggesting to previous investigators that the lipase PLRP2 might support CTL functions. Here, we further evaluate PLRP2 in CTLs. We found that PLRP2 was optimally induced in splenocytes by 3.5 x 10-8 M IL-4 by day 6 after activation and was restricted to CD8+ T cells. PLRP2 mRNA was detected inconsistently (and at low levels) after activation in the presence of IL-2. Cytotoxicity in 4 h 51Cr assays of WT CTLs was ∼3-fold the activity of PLRP2-/- CTLs cultured with IL-4 and, with IL-2, was unexpectedly ∼2 fold the activity of PLRP2-/- CTLs. Thus, PLRP2 gene ablation affected short-term (perforin-dependent) cytotoxicity, even under the IL-2 conditions. Other variables failed to account for the reduced cytotoxicity. Granzyme B levels, activation markers, and CD8+ T cell frequencies were similar for WT vs. PLRP2-/- CTLs (with either cytokine). Addition of rPLRP2 to IL-4 induced PLRP2-/- CTLs (or to cytotoxic granule extracts) failed to increase lysis, suggesting that the missing mediator is more than released PLRP2. Cytotoxicity of WT and PLRP2 -/- CTLs was similar in 2-day tumor survival assays with IL-4, which can be mediated by perforin-independent mechanisms. We conclude that extracellular PLRP2 lipase is unable to directly augment the cytotoxicity that was lost by PLRP2 ablation and that after reevaluation, the question of what is PLRP2's role in CD8 T cells is still unanswered.

Original languageEnglish
Pages (from-to)701-712
Number of pages12
JournalJournal of Leukocyte Biology
Volume86
Issue number3
DOIs
StatePublished - Sep 1 2009
Externally publishedYes

Keywords

  • CD8
  • eGFP-P815
  • pe T cellsrforin

Fingerprint Dive into the research topics of 'Pancreatic lipase-related protein 2 (PLRP2) induction by IL-4 in cytotoxic T lymphocytes (CTLs) and reevaluation of the negative effects of its gene ablation on cytotoxicity'. Together they form a unique fingerprint.

  • Cite this