Tu116 - Bac Transgenic Overexpression Mice Recapitulate the Immunologic Role of Exonic Variants of APOL1

Tuesday, June 21, 2022

6:15 PM – 7:45 PM PT

Presenting Author(s)

JP

John F. Pell, N/A, n/a

Postgraduate Associate
Yale University School of Medicine
New Haven, Connecticut, United States

Co-Author(s)

AR

Anand Reghuvaran, PhD

Postdoctoral Associate
Yale University School of Medicine
New Haven, Connecticut, United States
KB

Khadija Banu, PhD

Associate Research Scientist
Yale University School of Medicine
New Haven, Connecticut, United States
SN

Soichiro Nagata, PhD

Postdoctoral Associate
Yale University School of Medicine
New Haven, Connecticut, United States
SI

Shuta Ishibe, MD

Professor of Medicine (Nephrology)
Yale University School of Medicine
New Haven, Connecticut, United States
IC

Irene Chernova, MD, PhD

Postdoctoral Associate
Yale University School of Medicine
New Haven, Connecticut, United States
MM

Madhav Menon, MBBS, MD

Associate Professor
Yale University School of Medicine
New Haven, Connecticut, United States

Exonic variants (G1,G2) in apolipoprotein A1(APOL1) increase the risk of kidney disease (CKD) in African-Americans (vs G0 major allele). While kidney cell expression of APOL1 is necessary for CKD, our recent findings showed that renal transplant recipients with G1 or G2 genotype also sustained increased allograft rejection rates. Ex vivo, NK cells, activated CD4/CD8 cells had higher APOL1 among immune cell subsets, and in G1 or G2 individuals these subsets showed enhanced activation by single cell transcriptomics. Since APOL1 is restricted to primates, we studied APOl1 variants in immune cells using a novel Bac-transgenic mouse model for G0, G1 or G2 expression under human APOL1 promoter(Bac-Tg). At baseline, splenocytes from Bac-tg mice showed similar proportions of CD4+, CD8+, CD19+ and innate immune- cell fractions between G0, G1, G2 Bac-Tg and WT mice(N=3 each). CD44+ or CD69+ CD4-Tcells were also similar between all Bac-Tg mice and WT mice. At baseline, we found a higher proportion of CD44+ CD8+ Tcells in G1-Bac-Tg mice vs G0- or wild type (WT) mice (55% vs 18%; P< 0.001). CD8+CD44+ Tcells were similar in G2 vs G0 comparisons at baseline. Next, we performed CFSE labelled proliferation assays (72 hours) in isolated CD4 and CD8-Tcells. While CD4+ proliferation was similar between APOL1 Bac-Tg mice, we observed greater proliferation in G1 or G2 CD8-Tcells vs G0 or WT mice (ANOVA P< 0.05). Hence, we show that human Bac-tg APOL1 mice recapitulate the CD8+ activation observed in human data, and serve as a model to study APOL1-related immune phenotypes.