Integrin α_Dβ₂ is expressed by leukocytes in human lung.

<p>A. Tissue samples from a human subject with normal lungs who underwent autopsy after fatal head injury were fixed and stained for α_D with mAb 169A as outlined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112770#s2" target="_blank">Materials and Methods</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112770#pone.0112770-Albertine1" target="_blank">[34]</a>. Microscopic evaluation revealed α_Dβ₂⁺ macrophages in alveolar spaces (black arrow). There are also scattered α_D⁺ cells in alveolar walls (white arrows), which may be interstitial macrophages and/or dendritic cells. This image is representative of findings from analysis of lung tissue from three subjects who died without lung disease or injury. B. Autopsy samples from a patient who died with acute respiratory distress syndrome <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112770#pone.0112770-Albertine1" target="_blank">[34]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112770#pone.0112770-Harris4" target="_blank">[45]</a> were fixed, stained for α_D, and examined by light microscopy. Numerous α_Dβ₂⁺ macrophages were detected in alveolar spaces and walls. In some fields α_Dβ₂⁺ neutrophils were also present (not shown). Lung samples from 3 patients who died with acute lung injury or ARDS as defined by consensus criteria <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0112770#pone.0112770-Matthay1" target="_blank">[44]</a> were examined. We found α_Dβ₂⁺ leukocytes in the alveoli in each case.