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. 2021 Mar 21;117(4):1217-1228.
doi: 10.1093/cvr/cvaa187.

Class switching and high-affinity immunoglobulin G production by B cells is dispensable for the development of hypertension in mice

Yuhan Chen  1   2 , Bethany L Dale  2 , Matthew R Alexander  3 , Liang Xiao  4 , Mingfang Ao  4 , Arvind K Pandey  4 , Charles D Smart  2 , Gwendolyn K Davis  4 , Meena S Madhur  2   3   4   5
Affiliations

Class switching and high-affinity immunoglobulin G production by B cells is dispensable for the development of hypertension in mice

Yuhan Chen et al. Cardiovasc Res. .

Abstract

Aims: Elevated serum immunoglobulins have been associated with experimental and human hypertension for decades but whether immunoglobulins and B cells play a causal role in hypertension pathology is unclear. In this study, we sought to determine the role of B cells and high-affinity class-switched immunoglobulins on hypertension and hypertensive end-organ damage to determine if they might represent viable therapeutic targets for this disease.

Methods and results: We purified serum immunoglobulin G (IgG) from mice exposed to vehicle or angiotensin (Ang) II to induce hypertension and adoptively transferred these to wild type (WT) recipient mice receiving a subpressor dose of Ang II. We found that transfer of IgG from hypertensive animals does not affect blood pressure, endothelial function, renal inflammation, albuminuria, or T cell-derived cytokine production compared with transfer of IgG from vehicle infused animals. As an alternative approach to investigate the role of high-affinity, class-switched immunoglobulins, we studied mice with genetic deletion of activation-induced deaminase (Aicda-/-). These mice have elevated levels of IgM but virtual absence of class-switched immunoglobulins such as IgG subclasses and IgA. Neither male nor female Aicda-/- mice were protected from Ang II-induced hypertension and renal/vascular damage. To determine if IgM or non-immunoglobulin-dependent innate functions of B cells play a role in hypertension, we studied mice with severe global B-cell deficiency due to deletion of the membrane exon of the IgM heavy chain (µMT-/-). µMT-/- mice were also not protected from hypertension or end-organ damage induced by Ang II infusion or deoxycorticosterone acetate-salt treatment.

Conclusions: These results suggest that B cells and serum immunoglobulins do not play a causal role in hypertension pathology.

Keywords: B cells; Blood pressure; Hypertension; Immunity; Inflammation.

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Figures

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Graphical abstract
Figure 1
Figure 1
Repeated hypertensive stimulus induces formation of memory B cells. (A) Systolic blood pressure (SBP) was measured weekly by tail-cuff over 56 days of repeated Ang II infusion. WT mice were infused with 4 weeks of Ang II (490 ng/kg/min), followed by a wash-out period of 2 weeks, and then 2 weeks of Ang II (140 ng/kg/min) or vehicle (n = 4–5). (B) Percentage of B memory cells (IgG+CD38−CD80+) of total CD45+ cells in bone marrow from WT mice infused with repeated Ang II or vehicle (n = 7–10). (C) Percentage of plasma cells (CD19−B220−CD138+IgK+) of total CD45+ cells in bone marrow from WT mice infused with repeated Ang II or vehicle (n = 7–10). Data are expressed as mean ± SEM (A) or box-and-whisker plots (B and C); *P < 0.05, **P < 0.01 by two-way ANOVA with repeated measures (A) or Student’s t-test (B and C).
Figure 2
Figure 2
IgG from hypertensive mice is not sufficient to induce a hypertensive response in recipient mice treated with a low dose of Ang II. (A and B) Schematic diagram of IgG transfer study. IgG was purified from serum of WT mice infused with 4 weeks of Ang II (490 ng/kg/min; HTN IgG) or vehicle (Vehicle IgG). Purified IgG was administered to WT mice twice weekly during 2 weeks of low-dose Ang II (140 ng/kg/min) infusion. (C) Flow cytometric quantification of total leukocytes (CD45+), T cells (CD3+), CD4+ T cells, CD8+ T cells, B cells (CD19+), macrophages (F4/80+), NK cells (NK1.1+), and neutrophils (CD11b+Ly6G+) in the aorta from both groups (n = 10). (D) Systolic BP was measured by tail-cuff weekly over 14 days of Ang II infusion (n = 12). (E) Endothelium-dependent relaxation in response to increasing doses of acetylcholine (Ach) (left) and endothelium-independent relaxation in response to increasing doses of sodium nitroprusside (SNP) (right) were measured in isolated mesenteric arterioles (n = 11). (F) Albumin:creatinine ratio was measured in both groups by ELISA (n = 11–12). (G) Splenic CD4+ T-cell production of IL-17A and IL-21 and CD8+ T-cell production of IFNγ were quantified in both groups by ELISA (n = 7–9). Data are expressed as box-and-whisker plots (C, F, and G) or mean ± SEM (D and E); *P < 0.05 by Student’s t-test or Mann–Whitney U test (C).
Figure 3
Figure 3
High-affinity class-switched immunoglobulins are not necessary for a hypertensive response to Ang II in female mice. (A) SBP, diastolic BP (DBP), and HR were measured invasively weekly using carotid radiotelemetry over 28 days of Ang II (490 ng/kg/min) infusion in female Aicda+/+ and Aicda−/− mice (n = 4–5). (B and C) Flow cytometric quantification of total leukocytes (CD45+), T cells (CD3+), B cells (CD19+), macrophages (F4/80+), NK cells (NK1.1+), and neutrophils (CD11b+Ly6G+) in the aorta from both groups (n = 19–22 for B and n = 6–9 for C). (D) Representative images of bright-field aortic media thickness by Picrosirius Red staining. Scale bar: 100 µm. (E) Quantification of aortic media thickness in Aicda+/+ and Aicda−/− mice infused with vehicle or Ang II for 4 weeks (n = 5–6). (F) Albumin:creatinine ratio was measured in both groups by ELISA (n = 10–16). (G) SBP was measured by tail-cuff weekly in female Aicda+/+ and Aicda−/− mice infused with 4 weeks of Ang II (490 ng/kg/min), followed by a wash-out period of 2 weeks, and then 2 weeks of Ang II (140 ng/kg/min) (n = 9). Data are expressed as box-and-whisker plots (B, C, E, and F) or mean ± SEM (A and G); ***P < 0.001,****P < 0.0001 by two-way ANOVA (E).
Figure 4
Figure 4
High-affinity class-switched immunoglobulins are not necessary for a hypertensive response to Ang II in male mice. (A) SBP was measured by tail-cuff weekly over 28 days of Ang II infusion (490 ng/kg/min) in male Aicda+/+ and Aicda−/− mice (n = 14–15). (B) Flow cytometric quantification of total leukocytes (CD45+), T cells (CD3+), B cells (CD19+), macrophages (F4/80+), NK cells (NK1.1+), and neutrophils (CD11b+Ly6G+) in the aorta of both groups (n = 4–7). (C) Splenic CD4+ T-cell production of IL-17A and IL-21 and CD8+ T-cell production of IFNγ were quantified in both groups by ELISA (n = 4–7). (D) Albumin:creatinine ratio was measured in both groups by ELISA (n = 10–11). (E) SBP was measured by tail-cuff weekly in male Aicda+/+ and Aicda−/− mice infused with 4 weeks of Ang II (490 ng/kg/min), followed by a wash-out period of 2 weeks, and then 2 weeks of Ang II (140 ng/kg/min) (n = 9–11). Data are expressed as box-and-whisker plots (B, C, and D) or mean ± SEM (A and E). n.s., not significant.
Figure 5
Figure 5
Global B-cell deficiency does not affect the hypertensive response to Ang II. (A) SBP, DBP, and HR were measured invasively weekly using carotid radiotelemetry over 28 days of Ang II infusion (490 ng/kg/min) in male WT and µMT−/− mice (n = 3–5). (B) Flow cytometric quantification of total leukocytes (CD45+), T cells (CD3+), CD4+ T cells, CD8+ T cells, B cells (CD19+), and macrophages (F4/80+) in the aorta of both groups (n = 8–9). (C) Representative images of bright-field aortic media thickness by Picrosirius Red staining. Scale bar: 100 µm. (D) Quantification of aortic media thickness in male WT and µMT−/− mice infused with vehicle or Ang II for 4 weeks (n = 5–7). (E) Splenic CD4+ T-cell production of IL-17A and IL-21 and CD8+ T-cell production of IFNγ were quantified in both groups by ELISA (n = 5–8). (F) Albumin:creatinine ratio was measured in both groups by ELISA (n = 10–13). (G) SBP was measured by tail-cuff weekly in male WT and µMT−/− mice infused with 4 weeks of Ang II (490 ng/kg/min), followed by a wash-out period of 2 weeks, and then 2 weeks of Ang II (140 ng/kg/min) (n = 21–24). Data are expressed as box-and-whisker plots (B, D, E, and F) or mean ± SEM (A and G); **P < 0.01, ***P < 0.001, ****P < 0.0001 by Student’s t-test or Mann–Whitney U test (B and E) or two-way ANOVA (D).
Figure 6
Figure 6
Global B-cell deficiency does not affect the hypertensive response to DOCA-salt. (A) SBP was measured weekly by tail-cuff over 21 days of DOCA-salt treatment in male WT and µMT−/− mice (n = 5–8). (B) Endothelium-dependent relaxation in response to increasing doses of Ach (left) and endothelium-independent relaxation in response to increasing doses of SNP (right) were measured in isolated mesenteric arterioles (n = 3). (C) Flow cytometric quantification of total leukocytes (CD45+), T cells (CD3+), B cells (CD19+), macrophages (F4/80+), CD4+ T cells, and CD8+ T cells in the aorta of both groups (n = 6–8). (D) Albumin:creatinine ratio was measured in both groups by ELISA (n = 6–8). Data are expressed as mean ± SEM (A and B) or box-and-whisker plots (C and D); *P < 0.05, **P < 0.01, ***P < 0.001 by Student’s t-test or Mann–Whitney U test (C). n.s., not significant.
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References

    1. GBD 2015 Risk Factors Collaborators. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet 2016;388:1659–1724. - PMC - PubMed
    1. Whelton PK, Carey RM, Aronow WS, Casey DE Jr, Collins KJ, Dennison Himmelfarb C, DePalma SM, Gidding S, Jamerson KA, Jones DW, MacLaughlin EJ, Muntner P, Ovbiagele B, Smith SC Jr, Spencer CC, Stafford RS, Taler SJ, Thomas RJ, Williams KA Sr, Williamson JD, Wright JT Jr.. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Hypertension 2018;71:1269–1324. - PubMed
    1. Blacher J, Evans A, Arveiler D, Amouyel P, Ferrieres J, Bingham A, Yarnell J, Haas B, Montaye M, Ruidavets JB, Ducimetiere P; on behalf of the PRIME Study Group. Residual cardiovascular risk in treated hypertension and hyperlipidaemia: the PRIME Study. J Hum Hypertens 2010;24:19–26. - PubMed
    1. Struthers AD. A new approach to residual risk in treated hypertension—3P screening. Hypertension 2013;62:236–239. - PubMed
    1. Norlander AE, Madhur MS, Harrison DG.. The immunology of hypertension. J Exp Med 2018;215:21–33. - PMC - PubMed

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