Sex Differences in T Cell Migration from the Spleen to the Kidney in Mice at Baseline and in Response to Angiotensin II Infusion

Abstract

Decades of research has indicated that T cells contribute to the development of hypertension and target organ damage. There is a critical role of spleen-derived T cells in angiotensin II-mediated hypertension and kidney damage in mice. Splenectomy abolished sex differences in the development of hypertension in spontaneously hypertensive rats, suggesting sex differences in the spleen-kidney immune axis. It is well-appreciated that immune cells migrate from different tissues to infiltrate organs. However, whether there are sex differences in T cell migration from the spleen to the kidney remained unexplored. Thus, we hypothesized that male mice would show higher immune cell migration from the spleen to the kidney at baseline and in response to angiotensin II infusion when compared to female mice. To quantify T cell migration in male and female mice, we utilized Kikume Green-Red (KikGR) transgenic mice that ubiquitously express the kikume green protein in all cells throughout the body, and this protein can be stably photoconverted to kikume red with exposure to 405 nm blue light. We specifically photoconverted mouse spleens with 10-minute exposure to blue light and infused angiotensin II via mini-pump implantation (490 ng/kg*min) in half of the photoconverted mice. After 3 days post-photoconversion, all mice were sacrificed, and both kidneys were removed for analysis via spectral flow cytometry to determine spleen-derived infiltrating immune cells (CD45+, KikRed+ cells) as well as spleen-derived T cells (CD45+, KikRed+, CD3+) in the kidney. There were no differences in the immune cell profiles found between left and right kidneys within each sex (p = 0.8 [male kidneys] and 0.8292 [female kidneys], n = 6-10 kidneys per group). At baseline, we found significantly increased spleen-derived immune cells in the kidneys of male compared to female mice (P = 0.0173, n = 3-5 per group). In addition, sex was a significant factor in spleen-derived T cell percentages within the kidney (Two-Way ANOVA, P = 0.029, n = 3-5 mice). In response to 3 days of angiotensin II infusion, spleen-derived immune cells were significantly higher in the kidneys of males compared to females (P = 0.0499, n = 3-5 mice). We conclude that there is reduced immune cell migration to the kidney from the spleen at baseline and in response to angiotensin II infusion in female mice, which may contribute to the lower blood pressure and kidney damage observed in female mice. NIH TL1 DK139566 to LNB, NIH R01 DK134562 to JSP. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.