CD28 costimulation regulates genome-wide effects on alternative splicing

PLoS One. 2012;7(6):e40032. doi: 10.1371/journal.pone.0040032. Epub 2012 Jun 29.

Abstract

CD28 is the major costimulatory receptor required for activation of naïve T cells, yet CD28 costimulation affects the expression level of surprisingly few genes over those altered by TCR stimulation alone. Alternate splicing of genes adds diversity to the proteome and contributes to tissue-specific regulation of genes. Here we demonstrate that CD28 costimulation leads to major changes in alternative splicing during activation of naïve T cells, beyond the effects of TCR alone. CD28 costimulation affected many more genes through modulation of alternate splicing than by modulation of transcription. Different families of biological processes are over-represented among genes alternatively spliced in response to CD28 costimulation compared to those genes whose transcription is altered, suggesting that alternative splicing regulates distinct biological effects. Moreover, genes dependent upon hnRNPLL, a global regulator of splicing in activated T cells, were enriched in T cells activated through TCR plus CD28 as compared to TCR alone. We show that hnRNPLL expression is dependent on CD28 signaling, providing a mechanism by which CD28 can regulate splicing in T cells and insight into how hnRNPLL can influence signal-induced alternative splicing in T cells. The effects of CD28 on alternative splicing provide a newly appreciated means by which CD28 can regulate T cell responses.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alternative Splicing / genetics*
  • Animals
  • Antigens, Differentiation, T-Lymphocyte / metabolism
  • CD28 Antigens / genetics
  • CD28 Antigens / metabolism*
  • CD4-Positive T-Lymphocytes / metabolism
  • Down-Regulation / genetics
  • Gene Expression Profiling
  • Genome / genetics*
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism
  • Interleukin-3 / metabolism
  • Lymphocyte Activation / genetics
  • Mice
  • Mice, Inbred C57BL
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Antigen, T-Cell / metabolism
  • Receptors, CCR / metabolism
  • Signal Transduction / genetics
  • Transcription, Genetic
  • Up-Regulation / genetics

Substances

  • Antigens, Differentiation, T-Lymphocyte
  • CC chemokine receptor 9
  • CD226 antigen
  • CD28 Antigens
  • Heterogeneous-Nuclear Ribonucleoproteins
  • Interleukin-3
  • RNA, Messenger
  • Receptors, Antigen, T-Cell
  • Receptors, CCR
  • hnRNPLL protein, mouse