Progression of pathological changes in the lungs of HK<i>C.n.-</i> and <i>C. neoformans</i> strain H99γ-immunized mice following secondary challenge with wild-type cryptococci.

<p>Histological samples were prepared as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0006854#s4" target="_blank">Methods</a>. Digital photographs of H&E stained slides were taken under the light microscope at 10X and 40X power objectives. Note the progressive growth and spread of <i>C. neoformans</i> (red arrows), concurrent development of “loose” inflammatory infiltrates (A–F) in the lungs of non-protected mice, and the hallmarks of allergic broncho-pulmonary mycosis (ABPM) pathology [eosinophilia (yellow arrows) and extended macrophages harboring live organisms (E–F)]. In protected mice, note rapid formation of “tight” mononuclear infiltrates and the absence of <i>C. neoformans</i> growth in the alveolar space (G–J) and a rapid resolution of the inflammatory response that subsides to the well marginalized “cuffs” of neolymphatic tissue within the bronchovascular bundle (black arrows) with the concurrent clearance of inflammation from the alveolar space (K, L). Data are representative of 4 experiments using 3 mice per experiment.