D4 cells bind to lung vascular endothelium and interstitium. (A) D4 cells (1 × 106) were applied to 10-μM-thick frozen lung sections on glass slides in HBSS buffer containing 1 mM CaCl2 and 1 mM MgCl2 with or without 5 mM EDTA. Slides were placed on a rotary shaker for 20 minutes at 70 rpm at room temperature. Slides were rinsed in HBSS to remove unbound cells, fixed in 2% glutaraldehyde, and stained with Giemsa stain. For blocking experiments, D4 cells or lung sections were incubated with 20 μg/mL of appropriate mAb in 200 μL HBSS for 30 minutes and washed prior to use in the assay. Control antibodies against major histocompatibility complex (MHC) class I or CD3 did not inhibit binding (data not shown). (i) Untreated cells. (ii) EDTA. (iii) LFA-1. (iv) ICAM-1. (v) VLA-4. (vi) VCAM-1. Original magnification, × 40. (B) Data are expressed as cells bound to the lung section per field of view as a percent of cells bound in the untreated .group ± SD. Data pooled from 3 independent experiments are shown. *Significantly different (P < .001) from untreated group.
