Fig. 1. IL-2 complexes prevent acute rejection of lung allografts.
a C57BL/6 (H-2b) mice were pre-treated with PBS or IL-2/JES6-1 complexes (IL-2cx) on days −4, −3, and −2, followed on day 0 by orthotopic transplantation of a left lung from BALB/c (H-2d) mice. b Macroscopic view of grafted (L, left; white arrowheads) and endogenous (R, right) lungs in PBS- (top panels) and IL-2cx-treated mice (bottom panels) on indicated days (d5–d90) after lung transplantation. c Representative hematoxylin and eosin (HE) staining of grafted lungs of PBS- (top panels) and IL-2cx-treated mice (bottom panels) on indicated days. Scale bars = 200 μm. d–f Scoring of rejection based on adapted International Society for Heart and Lung Transplantation (ISHLT) grade A (d; acute rejection), grade B (e; airway inflammation), and grade C (f; chronic airway rejection) in PBS- (open circles) and IL-2cx-treated mice (open squares). Symbols represent individual mice and horizontal red bars the median of n ≥ 6 mice. F/I indicates fibrotic or infarcted tissue. Data are presented as mean ± SD of n ≥ 6 mice of 2–3 independent experiments. Statistical comparisons in (d–f) were calculated using two-sided Mann–Whitney U test with calculated p values shown. ns not significant.