Whereas no substantial differences were found throughout the infection with either strain in alveolar macrophages (Fig. 3A), neutrophils (Fig. 3C), CD8+ T cells (Fig. 3E), and B cells (Fig. 3F), significantly fewer inflammatory monocytes (Fig. 3B) and CD4+ T cells (Fig. 3D) were detected at day 20 postinfection in the lungs of mice infected with the Δnrp strain. This evidence concerns the gene CD4 and infection.