Intravascular space (plasma) was labeled with iv injected albumin–Alexa Fluor 594 (red). Female 4- to 6-week-old NZM WT (A and B) and NZM.BAFFTg (C–E) mice were treated with l-NAME and high-salt diet (HS) (B) or vehicle (A and C) followed by iv injection of FACS-sorted splenic activated memory T cells (sAMTs) (A–C). All transferred activated memory T cells were obtained from 7- to 9-month-old NZM.2328 female mouse donors. (D) sAMTs were preincubated with HA before iv injection. (E) sAMTs were preincubated with anti-CD44 antibody (KM81) before iv injection. (F) Summary of the number of sAMTs homed in glomeruli of the different groups of mice (n = 9–13 glomeruli from n = 4 mice for A–D and n = 3 mice for E). (G–Q) Fluorescence labeling and MPM imaging of endogenous CD3⁺CD44⁺ T cells, in C57BL/6 (n = 3), NZM WT (n = 3), and NZM.BAFFTg (n = 10) mouse glomeruli (4–6 weeks old) and NZM WT (7–9 months, n = 1). (G, I, K, and M) Representative images at baseline before and (H, J, L, and N) after endogenous T cells labeled in same glomeruli. (O) Image of the same glomerulus as in N 1 hour after H injection. (P) Overview image of a large kidney surface area in a 4-week-old female NZM.BAFFTg mouse. Note the high density of endogenous T cells (green) in 3 glomeruli (G) compared with adjacent tubulointerstitial areas. (Q) Summary of the number of CD3⁺CD44⁺ T cells homed in glomeruli of different mouse groups at 4–6 weeks. (R) Normalized density of CD44⁺ cells homed to glomeruli after acute H injection, compared with baseline (dotted line at 100%). Scale bars: 50 μm. Values are expressed as means ± SEM, *P < 0.0001 based on using 1-way ANOVA followed by Tukey’s multiple-comparisons test (F–Q) and unpaired Student’s t test (R). Positive cells are depicted by white arrows. HA, hyaluronic acid; H, hyaluronidase.