Figure 5.

Pregnancy and hormonally-induced adhesion of CD56^bright NK cells to uterine tissues and lymphoid tissue HEV is mediated by vascular addressins. CD56-fluorescent labeled human PBL were incubated with L-selectin blocking mAb (DREG-56) or with FN40 prior to frozen-section adhesion assays using uterine tissues (A) or lymphoid tissues (B). Alternatively, tissue cryosections were preincubated with function blocking mAb specific for PNAd (MECA-79), MAdCAM-1 (MECA-367), or VCAM-1 (20μg/ml). In A, CD56-pre-labeled cells were scored by fluorescence microscopy (high power fields; HPF). Data are the mean ± SD and are representative of results from multiple experiments (n>5). † Indicates significant difference from the oil placebo treatment groups (p<0.05, Student’s t test). *Function-blocking mAb specific for L-selectin (DREG-56) or α₄β₇ integrin (DATK-32) significantly reduced adhesion compared with untreated controls (p<0.001 using Student’s t test). In B, relative adhesion to HEV was calculated based on virgin (V) control values. Because of the low number of CD56^bright cells bound per LN or PP HEV relative to the total PBL population (i.e., 1–2 %), a total of 500 HEV were counted in triplicate for each condition.