0000000000330959
AUTHOR
Alexandra Helmke
Aggravated Atherosclerosis and Vascular Inflammation With Reduced Kidney Function Depend on Interleukin-17 Receptor A and Are Normalized by Inhibition of Interleukin-17A
Visual Abstract
Surface-bound bovine serum albumin carrier protein as present in recombinant cytokine preparations amplifies T helper 17 cell polarization
AbstractUnderstanding of T helper 17 lineage (TH17) polarization has been significantly promoted by cell culture experiments that reduce the complexity of the in vivo environment. We here investigated TH17 amplification by coating of cytokine preparations. Cytokine preparations coated to the surface compared to the same amount given in solution significantly enhanced TH17 polarization assessed by flow cytometry and interleukin (IL)-17A, IL-17F and RORγt mRNA expression. T cell proliferation and TH1 polarization were similarly enhanced while TREG polarization was impeded. TH17 amplification was replicated by coating the plate with low amounts of FCS or albumin as used as carrier protein for …
Figure 3: IL-17 Receptor A Increases Atherosclerotic Inflammation in Renal Impairment
LDLr–/– and Il17ra–/–LDLr–/– mice were kept on a high-fat diet for 10 weeks after RI or ctrl surgery. (A to F) Aortic leukocytes were analyzed by using flow cytometry for all leukocytes (CD45), myeloid cells (CD11b), B cells (CD19), and T cells (αβ-T-cell receptor [TCR]). (A and D) Typical examples with CD11b+ myeloid cells among all leukocytes are shown in the upper rows and T cells and B cells among all nonmyeloid cells in the lower rows. (B, C, E, F) All leukocytes (B and E) and among CD11b+ myeloid cells granulocytes (PMN, Gr1HIGHF4/80LOWCD11cLOW) and expression of macrophage marker F4/80 and antigen presenting cell markers CD11c and major histocompatibility complex (MHC) II were invest…
Figure 2: Aortic Root Lesion Formation in Renal Impairment Is Enhanced by IL-17 Receptor A
LDLr–/– and Il17ra–/–LDLr–/– male mice were kept on a high-fat diet for 10 weeks after RI or ctrl surgery. (A and B) Aortic root lesions were assessed by histology (typical examples, bar indicates 500 μm, and statistical analysis of n = 5 to 6 per group LDLr–/– mice and n = 4 to 5 Il17ra–/–LDLr–/– mice from 3 independent experiments, 2-way ANOVA, significant effects of treatment group [p < 0.0001] and distance [p < 0.0001], no significant interaction for A or B). (C) Aortic roots were stained for CD11b (green) and CD11c (red) with nuclear counterstain (4',6-diamidino-2-phenylindole [DAPI], blue) (typical examples, 10× and 20× original magnification, bars indicate 500 and 250 μm, respe…
Figure 6: IL-17A Blockade Normalizes Inflammation in Established Atherosclerotic Lesions in Renal Impairment
(A to E)LDLr–/– mice after RI or ctrl were kept on a high-fat diet for a total of 12 weeks after RI. After 6 weeks, they were treated with anti–IL-17A antibody or isotype control. (B and C) Atherosclerotic root lesion size was assessed by histology (B, examples and [C] statistical analysis of n = 7 to 8 per group from 3 to 4 independent experiments, 2-way ANOVA, significant effects of treatment group [p = 0.018] and distance [p < 0.0001], no significant interaction). (D) Aortic roots were stained for CD11b (green) and CD11c (red) with nuclear counterstain (DAPI, blue) (typical examples, 10× and 20× original magnification, bars indicate 500 μm). (E) Flow cytometry of aortic leukocytes was…
Figure 1: IL-17 Receptor A Increases Advanced Atherosclerotic Lesion Size in Renal Impairment
(A to G)LDLr–/– and Il17ra–/–LDLr–/– male mice were kept on a high-fat diet for 20 weeks after unilateral nephrectomy (RI) or control (ctrl) surgery. (B to D) En face atherosclerotic lesion size was analyzed in the total aorta (C) and the aortic arch (D) (n = 5 to 6 per group from 2 independent experiments, Bonferroni after analysis of variance [ANOVA]). (E to G) Aortic root lesions were assessed by histology (E, typical examples, bar indicates 500 μm; F, statistical analysis of mean lesion size by Bonferroni after ANOVA). (G) Lesion according to longitudinal distance (2-way ANOVA, significant effects of treatment group [p < 0.0001] and distance [p < 0.0001], no significant interactio…
Figure 5: IL-17A Promotes Inflammatory Cytokine Expression in Endothelial Cells
(A) IL-17 receptor A (Il17ra) and auxiliary subunits Il17rc and Il17re mRNA expression was determined by using quantitative polymerase chain reaction (qPCR). Il17rb messenger ribonucleic acid (mRNA) was below detection limit (n = 4, 2 exp.). (B to I) Endothelial cells were stimulated for 2 h with 50 ng/ml IL-17A (B to E) or IL-17F (F to I). CCL2 (B and F), CXCL1 (C and G), IL-6 (D and H), and granulocyte-macrophage colony-stimulating factor (GM-CSF) (E and I) cytokine expression quantified by using qPCR (n = 8 from 4 independent experiments for each cytokine).
Figure 4: Role of Myeloid Cell IL-17 Receptor A in Aortic Inflammation
(A and B) IL-17 receptor A expression was determined by flow cytometry on aortic CD45+ leukocytes with and without the myeloid cell marker CD11b (A, n = 3 to 8) and blood leukocytes (B, n = 6 to 7 [2 independent experiments each]) data are expressed as mean fluorescence intensity (MFI), identically treated Il17ra–/– cells are shown as negative controls for comparison, Student t tests). (C and D) Aortic arches from Il17a–/– and Il17ra–/– mice were co-incubated for 1 h with myeloid cells from Il17a–/– or Il17ra–/– mice in the presence or absence of 50 ng/ml IL-17A and aortic myeloid cell content determined by using flow cytometry (n = 4 to 6 from 4 independent experiments, aortic live CD11b+ …