The Minor Allele of a Single Nucleotide Polymorphism in SH2B3 Promotes CD8+ T Cell IFNg Production, Hypertension Development, and Renal Damage

Friday, June 24, 2022

3:05 PM – 3:20 PM PT

Location: Salons 3/4

Authors: Matt Alexander, MD, PhD (Presenting Author) - Vanderbilt University Medical Center; Samuel R. Hank, BS (Co-Author) - Vanderbilt University Medical Center; Bethany Dale, PhD (Co-Author) - Vanderbilt University; Lauren Himmel, DVM, PhD (Co-Author) - Vanderbilt University Medical Center; Xue R. Zhong, PhD (Co-Author) - Vanderbilt University Medical Center; Charles Smart, BS (Co-Author) - Vanderbilt University; Yuhan R. Chen, PhD (Co-Author) - Vanderbilt University Medical Center; Nitin Prabakaran, BS (Co-Author) - Vanderbilt University; Brian Tirado, BS (Co-Author) - Vanderbilt University; Mingfang Ao, MD, PhD (Co-Author) - Vanderbilt University Medical Center; Daniel Levy, MD (Co-Author) - Framingham Heart Study and NHLBI/NIH; Meena Madhur, MD, PhD (Co-Author) - Vanderbilt University Medical Center

Presenting Author(s)

MA

Matt Alexander, MD, PhD

Vanderbilt University Medical Center
Nashville, Tennessee, United States

SH2B3 is an adaptor protein that negatively regulates growth factor and cytokine signaling. A common missense single nucleotide polymorphism in SH2B3 (rs3184504) results in substitution of tryptophan (Trp) for arginine (Arg) at amino acid 262 and is a top association signal for hypertension in human genome-wide association studies. Whether this variant causally impacts hypertension development and end-organ damage is unknown. We used CRISPR-Cas9 to engineer mice homozygous for the major and minor alleles of this SH2B3 polymorphism, resulting in Arg/Arg and Trp/Trp mice, respectively. Trp/Trp mice exhibited approximately 10 mm Hg higher systolic blood pressure with chronic angiotensin II (Ang II) infusion compared to Arg/Arg mice. Renal damage was also exacerbated in Ang II-treated Trp/Trp mice, as evidenced by significantly increased urinary albumin/creatinine ratio and renal perivascular fibrosis. In addition, renal CD8⁺ T cells from Ang II-treated Trp/Trp mice produced significantly more IFNg compared to Arg/Arg controls, and ex vivo stimulated splenic CD8⁺ T cells from Trp/Trp mice made 2.7-fold more IFNg. Interleukin-12 (IL-12)-induced IFNg production was greater in Trp/Trp compared to Arg/Arg treated CD8⁺ T cells. In addition, IL-12 enhanced Stat4 phosphorylation in Trp/Trp compared to Arg/Arg CD8⁺ T cells, suggesting that Trp-encoding SH2B3 exhibits less negative regulation of IL-12 signaling to promote greater IFNg production. Taken together, these results suggest that the Trp encoding allele of rs3184504 is causal for blood pressure elevation and renal dysfunction, at least in part through loss of SH2B3-mediated repression of T cell IL-12 signaling leading to enhanced IFNg production.