CD4 and infection: Antibody staining and flow cytometric analysis of immune cell populations performed prior to infection suggested that the proportion of dendritic cells (CD11c+MHCII+), alveolar macrophages (CD11c+F480+), and interstitial macrophages (CD11b+F480+) were comparable in the lungs of C57.BL/6 (wild-type [WT] control mice) and Adamts5-/- mice (Fig 1A–1C), as were the number of CD4+ and CD8+ T lymphocytes and B cells in the spleen (Fig 1D–1F).