FCGR2B and influenza: The analysis demonstrated the negative immunomodulatory effects of antibiotic treatment during influenza infection with suppression of pertinent immunologic functions in the VNAM group, such as “engulfment of cells,” “immune response of cells,” “leukocyte migration,” “phagocytosis,” “recruitment of blood cells,” and “response of phagocytes.” Accordingly, we evaluated expression of various phagocytosis receptors and found that alveolar macrophages in VNAM-treated mice had lower expression of Cd14, Marco, Clec4d, Fcgr1, Fcgr2b, and Fcgr3 (Figure 3, J–O).