Key Points
miR-139 is downregulated in CD8+ T cells in response to TCR stimulation.
miR-139 is not required for anti-influenza CTL responses.
miR-139 is required for anti–Listeria monocytogenes CTL responses.
Abstract
MicroRNAs (miRNAs/miRs) are small, endogenous noncoding RNAs that are important post-transcriptional regulators with clear roles in the development of the immune system and immune responses. Using miRNA microarray profiling, we characterized the expression profile of naive and in vivo generated murine effector antiviral CD8+ T cells. We observed that out of 362 measurable mature miRNAs, 120 were differentially expressed by at least 2-fold in influenza-specific effector CD8+ CTLs compared with naive CD8+ T cells. One miRNA found to be highly downregulated on both strands in effector CTLs was miR-139. Because previous studies have indicated a role for miR-139–mediated regulation of CTL effector responses, we hypothesized that deletion of miR-139 would enhance antiviral CTL responses during influenza virus infection. We generated miR-139−/− mice or overexpressed miR-139 in T cells to assess the functional contribution of miR-139 expression in CD8+ T cell responses. Our study demonstrates that the development of naive T cells and generation or differentiation of effector or memory CD8+ T cell responses to influenza virus infection are not impacted by miR-139 deficiency or overexpression; yet, miR-139−/− CD8+ T cells are outcompeted by wild-type CD8+ T cells in a competition setting and demonstrate reduced responses to Listeria monocytogenes. Using an in vitro model of T cell exhaustion, we confirmed that miR-139 expression similarly does not impact the development of T cell exhaustion. We conclude that despite significant downregulation of miR-139 following in vivo and in vitro activation, miR-139 expression is dispensable for influenza-specific CTL responses.
Footnotes
This work was supported in part by funding for a Ph.D. fellowship to M.Z. provided by the China Scholarship Council (201506160120); a grant awarded by Worldwide Cancer Research (16-1153) to P.D.K.; funds from Thomas Jefferson University; funds from the College of Medicine, Drexel University, Department of Microbiology and Immunology; and funds from Erasmus Medisch Centrum, Department of Immunology, and Erasmus MC Foundation – Daniel den Hoed.
J.L.H. performed influenza infections, in vitro assays, adoptive transfers, and flow cytometry; M.Z. developed and performed in vitro T cell exhaustion assays and flow cytometry; C.H.K. and C.J.S. performed retroviral transductions, infections, and flow cytometry; A.J.C., M.v.M., and I.B.-H. performed infections, flow cytometry, qRT-PCR, and mouse breeding; D.C.O., E.-A.B., H.A.F., and L.M.B. designed and performed Listeria monocytogenes–OVA experiments; Y.M.M. performed adoptive transfers and cell sorting; A.M., H.d.L., and S.J.E. generated miR-139 knockout mice; S.J.E. and C.J.S. generated the miR-139 OE plasmid; P.M.F. and I.R. provided expert guidance for the design and completion of the microarray profiling; J.L.H. and P.D.K. were responsible for study design; J.L.H., M.Z., and P.D.K. were responsible for data analysis and manuscript authorship; all authors discussed the results and commented on the manuscript.
The online version of this article contains supplemental material.
Abbreviations used in this article
- APL
- altered peptide ligand
- Eomes
- Eomesodermin
- FDR
- false discovery rate
- ICL
- interstrand cross-link
- LCMV
- lymphocytic choriomeningitis virus
- LM
- Listeria monocytogenes
- MFI
- median fluorescence intensity
- miRNA/miR
- microRNA
- MLN
- mediastinal lymph node
- OE
- overexpression
- PFA
- paraformaldehyde
- qRT-PCR
- quantitative real-time PCR
- sgRNA
- single-guide RNA
- TCF-1
- T cell-specific factor-1
- WSN-OVA
- Wilson Smith Neurotropic/33 expressing OVA(257-264)
- WT
- wild type
- Received June 10, 2020.
- Accepted November 15, 2021.
- Copyright © 2022 by The American Association of Immunologists, Inc.
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$37.50
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.
Log in using your username and password
In this issue
