Journal Article

The introduction of RNA-DNA differences underlies interindividual variation in the human IL12RB1 mRNA repertoire

Amy J. Turner, Halli E. Miller, Ulrich Broeckel, Jill Waukau, John M. Routes, Praful Aggarwal, Richard T. Robinson

2015

Overview

The gene interleukin-12 receptor β1 ( IL12RB1 ) regulates susceptibility to several human diseases, including mycobacterial disease (e.g., tuberculosis). Here, we demonstrate that many of the mRNAs transcribed from IL12RB1 in primary immune cells contain RNA-DNA differences (RDDs). RDDs are nucleotide differences between RNA and its encoding DNA and are introduced posttranscriptionally; in the case of IL12RB1 , RDDs are concentrated in cytokine-binding regions that are important for IL12RB1 function. This observation is significant, as it is the first demonstration to our knowledge that a mechanism of sequence diversification exists for a human cytokine receptor. Given IL12RB1 ’s importance to mycobacterial disease resistance, our data raise the intriguing possibility that individual differences in IL12RB1 RDD introduction contribute to differences in mycobacterial disease susceptibility. Human interleukin 12 and interleukin 23 (IL12/23) influence susceptibility or resistance to multiple diseases. However, the reasons underlying individual differences in IL12/23 sensitivity remain poorly understood. Here we report that in human peripheral blood mononuclear cells (PBMCs) and inflamed lungs, the majority of interleukin-12 receptor β1 ( IL12RB1 ) mRNAs contain a number of RNA-DNA differences (RDDs) that concentrate in sequences essential to IL12Rβ1’s binding of IL12p40, the protein subunit common to both IL-12 and IL-23. IL12RB1 RDDs comprise multiple RDD types and are detectable by next-generation sequencing and classic Sanger sequencing. As a consequence of these RDDs, the resulting IL12Rβ1 proteins have an altered amino acid sequence that could not be predicted on the basis of genomic DNA sequencing alone. Importantly, the introduction of RDDs into IL12RB1 mRNAs negatively regulates IL12Rβ1’s binding of IL12p40 and is sensitive to activation. Collectively, these results suggest that the introduction of RDDs into an individual’s IL12RB1 mRNA repertoire is a novel determinant of IL12/23 sensitivity.

• Publisher: National Acad Sciences,National Academy of Sciences
• Subject: Adult / Amino acids / Base Sequence / Biological Sciences / Deoxyribonucleic acid / DNA / DNA - metabolism / Gene Expression Regulation - drug effects / Genomics / Humans / Interleukin-12 - metabolism / Lung - drug effects / Lung - metabolism / Lung - pathology / Models, Biological / Molecular Sequence Data / Phytohemagglutinins - pharmacology / Pneumonia - genetics / Pneumonia - pathology / Protein Binding - drug effects / Receptors, Interleukin-12 - genetics / Receptors, Interleukin-12 - metabolism / Recombinant Proteins - biosynthesis / Ribonucleic acid / RNA / RNA - metabolism / RNA, Messenger - genetics / RNA, Messenger - metabolism