The trapping of DM-and D-USPIO particles in the atherosclerotic wall of rabbits was indicated by a remarkable decrease in SNR. Our histological and imaging analyses showed that DM-USPIO was taken up to a greater degree than D-USPIO. Based on our observations, we suggest that DM-USPIO is superior to D-USPIO for the study of atherosclerotic lesions. IL-15 Participates in the Respiratory Innate Immune Response to Influenza Virus Infection Following influenza infection, natural killer (NK) cells function as interim effectors by suppressing viral replication until CD8 T cells are activated, proliferate, and are mobilized within the respiratory tract. Thus, NK cells are an important first line of defense against influenza virus. Here, in a murine model of influenza, we show that virally-induced IL-15 facilitates the trafficking of NK cells into the lung airways. Blocking IL-15 delays NK cell entry to the site of infection and results in a disregulated control of early viral replication. By the same principle, viral control by NK cells can be therapeutically enhanced via intranasal administration of exogenous IL-15 in the early days post influenza infection. In addition to controlling early viral replication, this IL-15-induced mobilization of NK cells to the lung airways has important downstream consequences on adaptive responses. Primarily, depletion of responding NK1.1+ NK cells is associated with reduced immigration of influenza-specific CD8 T cells to the site of infection. Together this work suggests that local deposits of IL-15 in the lung airways regulate the coordinated innate and adaptive immune responses to influenza infection and may represent an important point of immune intervention. Influenza virus is a major human pathogen that causes substantial morbidity and mortality-approximately 36,000 deaths annually in the United States alone [1] . Combined with the severe economic burden imposed from seasonal influenza outbreaks and growing concerns over potential imminent influenza pandemics, there is considerable need for a firm understanding of the disease pathology, prevention strategies, and mechanisms of host defense against the virus [2] .