Effect of cryptococcal laccase on morphological patterns of pulmonary inflammation and pathological lesions in <i>C. neoformans</i> infected lungs.

<p>Lungs collected from H99-infected (A, C,) and <i>lac1Δ</i>-infected (B, D,) mice were perfused with buffered formalin, fixed, and processed for histology at week 3 postinfection. Representative photomicrographs of H&E + mucicarmine-stained slides taken at 40× (A, B) and 100× (C, D) objective power. Note that sections obtained from wt-infected lungs frequently revealed macrophages harboring intracellular cryptococci encircled by large capsular halos (black arrows) as compared to lung section obtained from <i>Lac1Δ</i>-infected lungs which revealed numerous macrophages with intracellular inclusions consistent with degraded cryptococcal organisms (blue arrows). Also, the extended macrophages in H99-infected mice are heavily laden with YM1/2 crystals (red arrows) which were not observed in <i>lac1Δ</i>-infected lungs. Lastly, note that H99 infection leads to the accumulation of eosinophils (yellow arrow) in the lung, compared to the accumulation of lymphocytes (green arrow) in <i>lac1Δ</i>-infected lungs.